Central Nervous System Disease and Outcome in Pediatric Acute Myeloid Leukemia: Results from NOPHO-DBH AML2012 Trial

Central Nervous System Disease and Outcome in Pediatric Acute Myeloid Leukemia: Results from NOPHO-DBH AML2012 Trial | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Central Nervous System Disease and Outcome in Pediatric Acute Myeloid Leukemia: Results from NOPHO-DBH AML2012 Trial Nira Arad-Cohen, Daniel Cheuk, Barbara De Moerloose, Jose Mavarro, and 16 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5449535/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 10 You are reading this latest preprint version Abstract Background: Central nervous system disease (CNS3) in pediatric acute myeloid leukemia (pAML) is reported in 6% to 29% of cases. However, its impact on event-free survival (EFS) and overall survival (OS) remains uncertain. This study evaluates the effect of CNS involvement at diagnosis on relapse and survival in patients treated on the NOPHO-DBH AML2012 protocol. Methods: Data from 931 pediatric AML patients in the NOPHO-DBH AML2012 protocol were analyzed, comparing outcomes, relapse rates, and survival between those with and without CNS disease. CNS-directed therapy included intensified intrathecal chemotherapy without irradiation. Results: Of 922 patients with available CNS status, 10.9% had CNS3 at diagnosis. CNS3 patients were younger (median age 3.5 vs. 8 years,P=0.001) with higher white blood cell counts (56.1x10 9 /L vs 18.7x10 9 /L,P<0.001) and higher frequency of other extramedullary disease (30.4% vs 11.3%,P<0.001) and inv(16)(P<0.001). EFS 5y was 71.5% for CNS-positive patients vs. 62.7% for CNS-negative (p=0.14), and OS 5y was 81.4% vs. 79.3% (p=0.54). Patients with CNS disease had a lower cumulative incidence of relapse (15.6% vs 26.5%,P=0.023), and CNS relapse occurred in 0.9% and 0.7% of patients with and without CNS disease. Conclusion: CNS disease at diagnosis in pAML does not adversely affect survival or treatment response. Health sciences/Medical research/Clinical trial design/Clinical trials/Phase III trials Health sciences/Diseases/Haematological diseases/Haematological cancer/Leukaemia/Acute myeloid leukaemia Health sciences/Diseases/Cancer/Cancer therapy/Chemotherapy Figures Figure 1 Introduction Pediatric acute myeloid leukemia (pAML) is a rare disease, accounting for 15–20% of childhood leukemia cases. Over the past few years, the 5-year overall survival (OS) rates for pAML patients have shown improvement, with some clinical trials achieving a survival rate of up to 80% ( 1 )( 2 )( 3 ). The frequency of central nervous system (CNS) disease in AML at the time of diagnosis ranges from 6–29% ( 4 )( 5 ). This surpasses the 0–4.2% rate observed in adult cohorts( 6 ). The diagnosis of CNS disease in AML involves lumbar puncture (LP) with cytological examination of the cerebrospinal fluid (CSF) as well as imaging in suspected cases. Studies have identified hyperleukocytosis, inv( 16 ), KMT2A gene rearrangements, and younger age as factors associated with CNS leukemia in pediatric AML ( 7 )( 8 )( 9 ). Other research has shown a lack of correlation with various demographic and clinical factors at diagnosis, such as race, sex, FAB subtype, coagulation abnormalities, hemoglobin or platelet levels, and white blood cell (WBC) count ( 4 ). Traditionally, the presence of CNS disease has been viewed as an adverse prognostic factor. The standard therapeutic approach involves intensified CNS-directed therapy, mainly frequent intrathecal (IT) chemotherapy as well as high-dose cytarabine. Nevertheless, the rationale for this intensified treatment has not been substantiated and is primarily based on studies conducted in the context of acute lymphoblastic leukemia ( 10 ). While the impact on outcomes remains uncertain, existing evidence suggests a limited prognostic effect on event-free survival (EFS) and overall survival (OS), with an increased occurrence of isolated CNS relapse in children initially diagnosed with CNS disease ( 5 )( 8 )( 11 ). The NOPHO-DBH AML2012 protocol started recruiting patients in 2013 and combined intensive response-guided induction therapy with an at the time novel risk stratification primarily based on measurable residual disease (MRD) using flow cytometry after induction therapy. The protocol has resulted in improved results with overall survival approaching 80% [3]( 12 ). Given the conflicting literature on the impact of CNS involvement in pAML, we found it important to conduct a comprehensive investigation of a large cohort of patients with CNS disease treated according to this highly effective protocol. Methods 1. Definitions: CNS disease (CNS3) was diagnosed if any of the following criteria were met: ≥5 WBCs/µL with blasts on cytospin, clinical symptoms consistent with CNS disease such as cranial nerve palsy or radiological evidence of leukemic infiltration in the CNS. Patients with CNS disease were recommended to have an MRI evaluation. Patients with < 5 WBC/ µL, regardless of the presence of blasts in cytospin, were classified as not having CNS disease. Traumatic tap (RBC ≥ 10 /µL) was registered but did not influence the classification of CNS disease. Extramedullary disease was defined as AML occurring at sites outside the bone marrow (BM) and CNS, such as skin, orbit, etc. 2. Patients Children and adolescents between 0 and 19 years of age with de novo AML were included in the NOPHO-DBH AML2012 protocol. Exclusion criteria were Down syndrome, acute promyelocytic leukemia, bone marrow failure syndromes, and secondary AML. In addition, patients with isolated CNS myeloid sarcoma were excluded from analysis. Enrollment of patients commenced in March 2013, encompassing participants from the Nordic countries (Denmark, Finland, Iceland, Norway, Sweden) and Baltic countries (Estonia, Latvia, Lithuania), as well as Belgium, Hong Kong, and The Netherlands. By May 2014, all countries, except for Hong Kong (which began in June 2016), had initiated the protocol. AML2012 included two randomizations, with some countries (Iceland and the Baltic countries) opting not to participate in the randomization process. Patients who did not undergo randomization were included in an observation cohort. Subsequently, Israel joined in 2016 and Spain in 2017, both without participating in the randomizations. The randomized comparison of mitoxantrone and liposomal daunorubicin (DNX, R1) came to an early close in October 2017, as DNX production was discontinued [3]. A second randomization (R2), focusing on the second induction (ADxE vs FLADx), reached its recruitment target of 300 patients in July 2021. The present study reports on all randomized and observational patients included until July 2023. The study was approved by competent authorities and ethical review boards in each country. Informed consent and/or assent, were acquired from patients and guardians in accordance with the Declaration of Helsinki. The trial was registered with the European Medical Agency (EUDract 2012-002934-35), and on www.clinicaltrials.gov (NCT01828489). 3. Treatment Patients were stratified into either the standard-risk (SR) or high-risk (HR) group. Response was assessed by MRD measurement using flow cytometry. The HR group comprised patients with ≥ 15% leukemic cells in the bone marrow (BM) after the 1st induction and/or ≥ 0.1% after the 2nd induction. Additionally, patients with FLT3 -ITD mutation without concurrent NPM1 mutation were classified into the HR group, irrespective of treatment response. All patients received two induction courses, with randomization in each course. SR group patients received three consolidation courses with high-dose cytarabine, except for those with inv( 16 ) who received only two. HR patients were scheduled for hematopoietic stem cell transplantation (HSCT) with the best available donor after one consolidation course. An overview of the therapy used in the AML2012 study is shown in Supplemental data. The protocol advised to perform a lumbar puncture (LP) on the sixth day of treatment, following 5 days of VP16 treatment, to minimize the risk of CNS bleeding. Patients without CNS disease and no malignant cells in cerebrospinal fluid (CNS1) received one IT-methotrexate (MTX) injection on day 6 of the first course and at the beginning of subsequent courses. If IT-MTX was administered alongside diagnostic procedures, the day 6 injection was omitted. CNS1 patients did not require additional CSF cytology evaluations. Patients with CNS2 (cytospin positive for leukemic cells with < 5 WBC/mm 3 ) had the same IT treatment as CNS1 but were evaluated with an LP on day 22 after course one. If the results were negative, they were treated as patients without CNS disease. Patients with CNS disease received age-adjusted triple IT (MTX, prednisone, cytarabine) injections twice weekly until the CSF was free from blasts followed by two additional injections. A minimum of four injections were given. CSF cytology was then evaluated on day 22 after the first course. Thereafter one triple IT was given at the start of each course. Cranial irradiation was not given. If cytology remained positive before the first consolidation course, the patient was regarded as refractory. Patients with CNS disease with focal symptoms without malignant blasts in CSF received triple IT twice weekly for two weeks (i.e. a total of four injections) and then one triple IT injection with each course. A persistent mass present on MRI after two induction courses required a biopsy to check for viable cells. CNS relapse was defined as the presence of leukemic cells in CSF cytospin with ≥ 5 WBC/µL or the detection of a tumor mass in the CNS exhibiting identical or very similar characteristics on biopsy, including morphology, immunophenotype, and cytogenetic analysis, as the original malignant cells. All treatment details, including diagnostic measures, response evaluation, toxicity, and outcome were registered in the AML 2012 database from which the data were extracted. Statistical Methods Differences in proportions were assessed with the chi-squared test. Mann-Whitney test was used to compare medians. Overall survival was defined as the time from entry until death of any cause. Event-free survival was defined as the time from entry until death, resistant disease, relapse, or second malignant neoplasm. All estimates are given at five years. Induction death was defined as death occurring before final BM evaluation after induction 2. Survival curves were constructed according to the method of Kaplan-Meier and 95% confidence intervals (Cis) calculated according to Link ( 13 ). Cumulative incidence of relapse (CIR) was calculated using competing risk analysis according to Fine and Gray. Competing events in the analysis were resistant disease, early death, death in CR1, and second malignant neoplasm ( 14 ). To estimate hazard ratios (HzRs) for univariate and multivariate models of EFS and OS, Cox proportional hazards models were used, and competing risk regression models were used to estimate HzR for CIR ( 14 ) ( 15 ). Analyses were performed with SPSS v29 (IBM SPSS Statistics) or R v4.0.3 (R Foundation). Results Patient characteristics Out of the 931 eligible patients registered on AML2012, data for CNS status were available for 92 2 patients. Among these, 102 (10.9%) had CNS disease at diagnosis. Table 1 illustrates the characteristics of all patients. The median observation time for patients alive was 49.5 months (range 2-131). Patients with CNS disease were younger compared to those without CNS disease (median 3.5 [range 0-17] vs. 8 years [0-18], P=0.001) and 36.3% of children with CNS disease were below 2 years of age. Patients with CNS disease demonstrated a higher median WBC (56.1 x10 9 /L [range: 1.5-517] compared to 18.7 x10 9 /L [range: 0.3-889] P < 0.001) and a higher frequency of extramedullary disease (30.4% vs. 11.3%, P < 0.001). The only cytogenetic aberration that was over-represented in patients with CNS disease was inv(16) (P < 0.001). Among the 102 patients with CNS disease, 33 (32.3%) were categorized as CNS disease based on clinical signs of CNS leukemia (such as facial nerve palsy or eye involvement) or radiographic evidence of an intracranial, intradural mass indicative of a chloroma. These patients did not have blasts in the CSF, (3 patients with no CSF data). Fifty-eight patients (56.8%) were classified as CNS disease solely due to having ≥ 5 WBCs in the CSF along with the presence of blasts. The remaining 11 patients exhibited both clinical or radiological findings and ≥ 5 WBCs with blasts. Patient outcomes For all patients, EFS 5y and OS 5y were 63.5% (CI 60.1-66.9) and 79.4% (CI 76.6-82.3). Figure 1 shows EFS and OS for patients with and without CNS disease. There was no significant difference in EFS in cases with (71.5% [CI 61.9-81.1]) or without (62.7% [CI 59.0-66.3], P=0.14) CNS disease, and similarly, no significant difference was observed for OS (81.4% [CI 73.3-89.5] vs 79.3% [CI 76.3-82.4], P=0.54). Furthermore, subgroup analyses of SR and HR groups exhibited no statistically significant differences for either EFS or OS as shown in Table 2A. Table 2B presents the treatment response. After two inductions, over 90% of patients achieved CR, both in the CNS positive and the CNS negative group. There was no difference in the distribution of risk groups between patients with and without CNS disease. Six patients with refractory disease had CNS disease at diagnosis. However, none of them failed to respond within the CNS, thus giving a complete CNS response in all cases. The CIR 5y was significantly lower for patients with CNS disease compared to those without (15.6% [CI 8.6-24.4] vs. 26.5% [CI 23.3-29.9], p=0.023). The difference remained significant (HzR 0.50 [CI 0.28-0.88], P=0.017) in a regression model including sex, genetic subtype, MRD after course 1, and log(WBC). Among all relapses, 1 out of 102 (0.9%) with CNS disease and 6 out of 820 (0.7%) without experienced relapse in CNS with or without BM involvement. Thus, CNS relapse was not more frequent in patients with CNS disease at primary diagnosis. Univariable analysis (Table 3A) showed that MRD after course 1 was strongly predictive of EFS and OS. Patients not achieving MRD <0.1% had significantly lower EFS (HzR 2.19 [CI 1.75-2.74], P<0.001)) and OS (HzR 2.57 [1.89-3.51], P<0.001) compared to those who had MRD <0.1%. The presence of CNS disease did not significantly impact EFS or OS (HzR 0.74 [CI 0.50-1.11] p=0.13 and HzR 0.94 [CI 0.57-1.55], p=0.81 respectively). Female sex was associated with lower OS but not EFS, and higher WBC count, both categorized and continuous, was associated with poorer EFS but not OS. The gene rearrangements/mutations FLT3 -ITD/ NPM1 wt and KMT2A rearrangement other than KMT2A :: MLLT3 were associated with lower EFS, while RUNX1 :: RUNX1T1 , CBFB :: MYH11 , and NPM1 mut were associated with better OS. Multivariate Cox regression analysis for EFS and OS based only on diagnostic parameters is summarized in Table 3B. It confirmed that CNS disease did not significantly affect EFS (HR 0.8 [0.53-1.21], p=0.29) or OS (HR 1.09 [0.65-1.82], p=0.76). Female sex was associated with lower OS (HR 1.46 [1.07-1.98], p=0.016) while higher log(WBC) at diagnosis negatively impacted EFS (HR 1.29, p=0.004). RUNX1 :: RUNX1T1 , CBFB :: MYH11, and NPM1 mut were associated with significantly better OS whereas FLT3 -ITD with wild-type NPM1 , KMT2A rearrangements other than KMT2A :: MLLT3, and the group with other aberrations, were associated with lower EFS but not with OS. When introducing response to treatment as an additional parameter in the multivariate Cox regression analysis (Table 3C), failure to achieve MRD <0.1% after course 1 emerged as the strongest factor associated with lower EFS (HzR 1.98 [1.56-2.51], p<0.001) and OS (HzR 2.38 [1.72-3.31], p<0.001) Female sex remained associated with worse OS (HzR 1.52 [CI 1.12-2.06], P=0.008) and log(WBC) with lower EFS (HzR 1.21 [CI 1.01-1.44], P=0.037). The genetic subtypes RUNX1 :: RUNX1T1 , CBFB :: MYH11, and NPM1 mut remained significantly associated with better OS whereas FLT3 -ITD with wild-type NPM1 , KMT2A rearrangements other than KMT2A :: MLLT3 and the group with other aberrations, had significantly lower EFS but not OS. Discussion The AML2012 protocol has included 931 patients and demonstrated some of the best overall results in pediatric AML with an EFS 5y of 63.5%, and OS 5y of 79.4%. We have attributed these improved results to intensive response-guided induction and the introduction of risk stratification primarily based on flow cytometric evaluation of response during and at the end of induction therapy. Apart from skin and orbital involvement, extramedullary leukemia in pAML most commonly affects the CNS ( 16 ). Previously, CNS involvement was reported to range from 6–29%. However, recent studies, have shown a narrower range of 8–16% ( 5 )( 8 )( 11 ), and our large cohort showed a frequency of 10.9%. Since some patients underwent a lumbar puncture (LP) only on the sixth day after beginning treatment, it is possible that malignant cells had already been cleared from the CSF, potentially leading to an underestimation of CNS disease. However, there was no difference in the frequency of CNS disease in patients with early lumbar puncture compared to those where the procedure was performed after day 5 from starting therapy (data supplement). In our study, the frequency of CNS disease was 17% in patients below two years at diagnosis which was higher than in the other age groups in which the frequency was 8–10% also in adolescents 15–17 years. Children with CNS disease also had higher WBC counts and more frequent AML with inv( 16 ). These risk factors have been previously observed in pediatric studies ( 4 )( 5 )( 7 )( 8 )( 9 )( 11 )( 17 )( 18 ). In adult patients, a lower occurrence of CNS leukemia is reported. A retrospective analysis of 3,240 adult patients diagnosed with de-novo AML between 1980 and 2008 across 11 clinical trials revealed that 36 patients (1.1%) had CNS disease at diagnosis, with incidence rates ranging from 0–4.2% among trials( 6 ). To some extent, this lower frequency may depend on that lumbar puncture is not always performed at diagnosis in adults. Previous studies conducted in pediatric cohorts have reached varying conclusions regarding the prognostic significance of CNS involvement at diagnosis. While the majority of studies suggest that there is no significant difference in EFS and OS between cases with CNS disease and those without ( 4 )( 5 )( 8 )( 9 )( 17 ), some studies have indicated an increased risk of relapse( 7 ), especially for isolated CNS relapse( 5 )( 7 )( 8 )( 11 )( 19 ). Multivariable Cox regression analysis (Table 3 B), both when based on diagnostic parameters alone (CNS involvement, sex, WBC, and genetic subtypes) as well as including treatment response in the model, failed to demonstrate any significant effect of CNS disease on both EFS and OS. In contrast, failure to achieve MRD < 0.1% after the first induction course is strongly associated with both decreased EFS and OS (HzR 2.19 CI 1.75–2.74 and 2.57 CI 1.89–3.51, respectively). In the full regression, other factors associated with decreased EFS were high WBC and the genetic subtypes FLT3 -ITD, KMT2A rearrangements other than KMT2A :: MLLT3 , and the large group with other aberrations. The latter group includes patients with potential poor risk aberrations such as CBFA2T3 :: GLIS2 , NUP98 translocations, del( 7 ), and del (5q). AML with RUNX1 :: RUNX1T1 , CBFB::MYH11 , and NPM1 mut were associated with better OS whereas, perhaps a bit surprisingly and unexplained, female sex with decreased OS (HzR 1.42 CI 1.04–1.92). The rate of CNS relapse in pAML patients with CNS disease at diagnosis varies significantly across different study groups( 20 ). European studies have consistently reported a higher CIR for CNS relapse in these patients (8% vs. 3%, respectively) [8][9]. In reports from Children’s Oncology Group (COG), CNS relapse rates were notably higher in patients classified as CNS3 (17.7%) and CNS2 (11.7%) compared to CNS1 patients (3.9%) [11]. However, EFS was around 53% in these studies suggesting that the treatment efficacy was lower than for AML2012 ( 21 )( 22 ). Similarly, the French ELAM02 protocol reported elevated relapse rates in patients with CNS disease, particularly for combined relapses (26.1% vs. 10% )( 5 ). Despite the increased rate of CNS relapses, these studies have not shown a significant decrease in overall survival in patients with CNS disease( 20 ). Although not significantly associated with EFS, we somewhat surprisingly found lower CIR in patients with CNS disease (16.5% vs 26.5%). This apparent discrepancy may be explained by the fact that there indeed was a trend for higher EFS in patients with CNS disease (71.5% vs 62.7%, P = 0.14) and slightly more early deaths for CNS disease. However, one can speculate if the additional IT therapy can have systemic effects leading to a decreased relapse rate. In the European studies, the indications for HSCT in first complete remission (CR) varied significantly between study groups, and no clear data exist on transplantation rates for patients with and without CNS involvement. The AIEOP group reported a 68% HSCT rate, while for BFM, DCOG/BSPHO, and NOPHO, only 11.5% of patients with CNS disease underwent HSCT( 23 )( 24 ). In the French ELAM02 trial, 30.7% of cases with CNS involvement and 30.3% without received HSCT after achieving CR, showing no significant difference between the two groups. In our cohort, a relatively low proportion of 22% of patients were treated with HSCT in first remission, and patients with CNS disease did not undergo HSCT more frequently. A similar distribution of risk groups is also observed in Table 2 B. Previously, the BFM administered preventive radiation therapy to children with AML ( 25 ). However, due to severe long-term side effects ( 26 ) and comparable outcomes to treatment without radiation, the current strategy for managing and preventing CNS disease in pAML relies on intensive systemic chemotherapy, mainly high-dose cytarabine, supplemented by IT treatment ( 10 ). Despite the use of IT-Cytarabine or triple IT for CNS prophylaxis among most groups ( 8 ) ( 10 )( 11 ), the NOPHO group has consistently utilized IT-Methotrexate for many years ( 9 ). Our protocol gave a frequency of CNS relapse of under 1%. Considering that adults typically do not receive IT chemotherapy prophylaxis unless presenting with CNS symptoms, our findings prompt a reassessment of the necessity of CNS prophylaxis for pediatric patients without initial CNS involvement. It might be that high-dose cytarabine in consolidation is sufficient for these patients, eliminating the necessity for IT therapy. Ideally, this should be tested in a randomized setting but given the low numbers of CNS events, this may be unfeasible. On the other hand, if intensified IT therapy in patients with CNS disease contributes to a lower relapse rate, one could speculate that this might be of benefit even for patients without CNS disease. The NOPHO-DBH AML2012 protocol recommended an LP to be performed on the sixth day of treatment, following five days of VP16 therapy, to reduce the risk of CNS bleeding. The effect of the timing of the diagnostic LP on the detection of CNS disease and the frequency of traumatic taps was assessed. The results indicated that the timing of the LP, whether conducted before or after day 5, did not significantly influence the detection rate of CNS disease or the incidence of traumatic taps. This suggests that VP16 administration during the early treatment phase does not compromise the diagnostic accuracy of LP for CNS disease (Supplementary data). Traumatic LPs, characterized by ≥ 10 RBC/𝜇L, raise concerns about introducing leukemic cells into CSF at initial diagnosis. However, studies by COG and European groups, including AIEOP, BFM, DCOG/BSPHO, and NOPHO found no significant differences in survival or treatment outcomes between traumatic and atraumatic LPs ( 8 )( 11 )( 27 ). These findings suggest that a traumatic tap at diagnosis does not lead to adverse outcomes. However, it is important to note that most of these patients were classified with CNS disease and received additional IT therapy. When preparing the AML2012 protocol, there was no strong evidence indicating that the presence of a low number of blasts (CNS2) affected the outcome ( 7 )( 28 ). Therefore, patients with CNS2 did not receive any additional IT treatment and, although registering traumatic tap, the presence of blasts was not documented if the WBC count was < 5/µL in CSF. When comparing EFS and OS of all patients as well as for those without CNS involvement with or without traumatic tap we found no difference in outcome (Supplementary data). Since the CNS relapse rate in our protocol was low, it does not appear to be influenced by traumatic tap or by a small number of leukemic cells in the CSF and thus it seems not justifiable to treat them with intensified IT therapy. In conclusion, in this extensive multicenter study, children diagnosed with AML and CNS disease tended to be younger, with elevated WBC counts and a higher frequency of inv( 16 ). However, CNS disease did not have an impact on CR rate, EFS, or OS. Additionally, patients with CNS disease at diagnosis tended to have a lower relapse rate, with very few relapses involving the CNS. With the treatment, including intensified IT therapy, and risk-adapted treatment stratification, used in AML2012, CNS disease at diagnosis of pAML is not an adverse prognostic factor. Declarations Data-sharing statement Requests for access to data used in this article for research purposes can be made to the senior author. Disclosures No conflicts of interest to disclose. Contributions NAC, DC, BDM, JMFN, HH, KJ, GK, ZK, OGJ, BL, JP, RP, CJP, KS, BZ, UNN, AT and JA designed the research study. NAC, DC, BDM, JMFN, HH, KJ, KLJ-D, GK, ZK, OGJ, BL, MM-K, JP, RP, CJP, KS, BZ, and JA obtained patients’ consent and collected clinical data. NAC, UNN, AT, and JA analyzed the data. NAC and JA wrote the paper. All authors reviewed and approved the final manuscript. Acknowledgment The study was financed by grants from the Swedish Children’s Cancer Foundation and the Swedish state under the agreement between the Swedish government and the county councils, the ALF agreement (ALFGBG-966256). References Aplenc R, Meshinchi S, Sung L, Alonzo T, Choi J, Fisher B, et al. 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Response-guided chemotherapy for pediatric acute myeloid leukemia without hematopoietic stem cell transplantation in first complete remission: Results from protocol DB AML-01. Pediatr Blood Cancer. 2019;66(5):e27605. Abrahamsson J, Forestier E, Heldrup J, Jahnukainen K, Jónsson OG, Lausen B, et al. Response-guided induction therapy in pediatric acute myeloid leukemia with excellent remission rate. J Clin Oncol Off J Am Soc Clin Oncol. 2011;29(3):310–5. Creutzig U, Zimmermann M, Bourquin JP, Dworzak MN, Fleischhack G, von Neuhoff C, et al. CNS irradiation in pediatric acute myleoid leukemia: Equal results by 12 or 18 Gy in studies AML-BFM98 and 2004. Pediatr Blood Cancer. 2011;57(6):986–92. Krull KR, Li C, Phillips NS, Cheung YT, Brinkman TM, Wilson CL, et al. Growth hormone deficiency and neurocognitive function in adult survivors of childhood acute lymphoblastic leukemia. Cancer. 2019;125(10):1748–55. Johnston DL, Alonzo TA, Gerbing RB, Aplenc R, Woods WG, Meshinchi S, et al. The Effect of Traumatic Diagnostic Lumbar Puncture in De Novo Pediatric Acute Myeloid Leukemia - a Report from the Children’s Oncology Group. Blood. 2016;128(22):4016. Creutzig U, Van Den Heuvel-Eibrink MM, Gibson B, Dworzak MN, Adachi S, De Bont E, et al. Diagnosis and management of acute myeloid leukemia in children and adolescents: Recommendations from an international expert panel. Blood. 2012;120(16):3167–205. Tables Table 1 to 3 are available in the Supplementary Files section. Additional Declarations There is NO conflict of interest to disclose. Supplementary Files supplement.pdf Tables.docx Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: revise 24 Feb, 2025 Review # 3 received at journal 27 Jan, 2025 Reviewer # 3 agreed at journal 08 Jan, 2025 Review # 1 received at journal 01 Dec, 2024 Reviewer # 2 agreed at journal 17 Nov, 2024 Reviewer # 1 agreed at journal 17 Nov, 2024 Reviewers invited by journal 14 Nov, 2024 Editor assigned by journal 14 Nov, 2024 Submission checks completed at journal 14 Nov, 2024 First submitted to journal 13 Nov, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5449535","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":378318265,"identity":"a50788f6-37f5-4108-8f37-628105ca6412","order_by":0,"name":"Nira 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Norén-Nyström","email":"","orcid":"https://orcid.org/0000-0001-5606-5442","institution":"Umeå University","correspondingAuthor":false,"prefix":"","firstName":"Ulrika","middleName":"","lastName":"Norén-Nyström","suffix":""},{"id":378318278,"identity":"9fa758a0-91fc-4b56-a67f-d381099db482","order_by":13,"name":"Josefine Palle","email":"","orcid":"","institution":"Uppsala University","correspondingAuthor":false,"prefix":"","firstName":"Josefine","middleName":"","lastName":"Palle","suffix":""},{"id":378318279,"identity":"a935b5fe-e483-4680-b419-78ef6f9a19b1","order_by":14,"name":"Ramunė Pasaulienė","email":"","orcid":"","institution":"Center of Pediatric Oncology and Hematology, Children's Hospital, Vilnius University","correspondingAuthor":false,"prefix":"","firstName":"Ramunė","middleName":"","lastName":"Pasaulienė","suffix":""},{"id":378318280,"identity":"0a4f0d8d-e7b6-4c90-91a8-13e59b0ac6a9","order_by":15,"name":"Cornelis Pronk","email":"","orcid":"https://orcid.org/0000-0002-0073-9660","institution":"Sk�ne University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Cornelis","middleName":"","lastName":"Pronk","suffix":""},{"id":378318281,"identity":"539595f1-61d3-4f23-ad78-790d387fd779","order_by":16,"name":"Kadri Saks","email":"","orcid":"","institution":"Tallinn Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Kadri","middleName":"","lastName":"Saks","suffix":""},{"id":378318282,"identity":"3adace6a-bd55-410c-aeca-8658e0687ab0","order_by":17,"name":"Anne Tierens","email":"","orcid":"https://orcid.org/0000-0002-5350-8313","institution":"University Health Network and University of Toronto","correspondingAuthor":false,"prefix":"","firstName":"Anne","middleName":"","lastName":"Tierens","suffix":""},{"id":378318283,"identity":"23249047-3c94-456f-98a3-c022ab0e445f","order_by":18,"name":"Bernward Zeller","email":"","orcid":"","institution":"University Hospital, Rikshospitalet","correspondingAuthor":false,"prefix":"","firstName":"Bernward","middleName":"","lastName":"Zeller","suffix":""},{"id":378318284,"identity":"254714da-3880-4e5a-9c51-5fdb231b0ac4","order_by":19,"name":"Jonas Abrahamsson","email":"","orcid":"","institution":"Queen Silvia Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jonas","middleName":"","lastName":"Abrahamsson","suffix":""}],"badges":[],"createdAt":"2024-11-13 21:30:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5449535/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5449535/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":71741820,"identity":"ac6c63a3-0b3a-4a2b-b49e-089aa9b0b058","added_by":"auto","created_at":"2024-12-18 08:19:54","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":146643,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEFS and OS of pediatric AML patients according to CNS status at diagnosis\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure1EFSandOS.png","url":"https://assets-eu.researchsquare.com/files/rs-5449535/v1/702d26625f6ac52a7871497e.png"},{"id":71741821,"identity":"77412e9a-3345-4579-aef2-0730fa66a3e1","added_by":"auto","created_at":"2024-12-18 08:19:59","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":578276,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5449535/v1/dc4dfac5-886f-4cd6-bfe2-74907e638f5d.pdf"},{"id":71741818,"identity":"95d87b50-a1e8-44db-8b5d-71644d7a2552","added_by":"auto","created_at":"2024-12-18 08:19:54","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":774119,"visible":true,"origin":"","legend":"","description":"","filename":"supplement.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5449535/v1/32b5570875e598d3b736d564.pdf"},{"id":71741819,"identity":"4776b5e0-137d-4862-9700-91ed8fa93d31","added_by":"auto","created_at":"2024-12-18 08:19:54","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":49691,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-5449535/v1/d6e76e055cbbd4009e64634e.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e conflict of interest to disclose.","formattedTitle":"Central Nervous System Disease and Outcome in Pediatric Acute Myeloid Leukemia: Results from NOPHO-DBH AML2012 Trial","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePediatric acute myeloid leukemia (pAML) is a rare disease, accounting for 15–20% of childhood leukemia cases. Over the past few years, the 5-year overall survival (OS) rates for pAML patients have shown improvement, with some clinical trials achieving a survival rate of up to 80% (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e)(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e)(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). The frequency of central nervous system (CNS) disease in AML at the time of diagnosis ranges from 6–29% (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). This surpasses the 0–4.2% rate observed in adult cohorts(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The diagnosis of CNS disease in AML involves lumbar puncture (LP) with cytological examination of the cerebrospinal fluid (CSF) as well as imaging in suspected cases.\u003c/p\u003e \u003cp\u003eStudies have identified hyperleukocytosis, inv(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e), KMT2A gene rearrangements, and younger age as factors associated with CNS leukemia in pediatric AML (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Other research has shown a lack of correlation with various demographic and clinical factors at diagnosis, such as race, sex, FAB subtype, coagulation abnormalities, hemoglobin or platelet levels, and white blood cell (WBC) count (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Traditionally, the presence of CNS disease has been viewed as an adverse prognostic factor. The standard therapeutic approach involves intensified CNS-directed therapy, mainly frequent intrathecal (IT) chemotherapy as well as high-dose cytarabine. Nevertheless, the rationale for this intensified treatment has not been substantiated and is primarily based on studies conducted in the context of acute lymphoblastic leukemia (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). While the impact on outcomes remains uncertain, existing evidence suggests a limited prognostic effect on event-free survival (EFS) and overall survival (OS), with an increased occurrence of isolated CNS relapse in children initially diagnosed with CNS disease (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe NOPHO-DBH AML2012 protocol started recruiting patients in 2013 and combined intensive response-guided induction therapy with an at the time novel risk stratification primarily based on measurable residual disease (MRD) using flow cytometry after induction therapy. The protocol has resulted in improved results with overall survival approaching 80% [3](\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Given the conflicting literature on the impact of CNS involvement in pAML, we found it important to conduct a comprehensive investigation of a large cohort of patients with CNS disease treated according to this highly effective protocol.\u003c/p\u003e \n\n \n\n "},{"header":"Methods","content":"\u003ch3\u003e1. Definitions:\u003c/h3\u003e\u003cp\u003eCNS disease (CNS3) was diagnosed if any of the following criteria were met: ≥5 WBCs/µL with blasts on cytospin, clinical symptoms consistent with CNS disease such as cranial nerve palsy or radiological evidence of leukemic infiltration in the CNS. Patients with CNS disease were recommended to have an MRI evaluation. Patients with \u0026lt; 5 WBC/ µL, regardless of the presence of blasts in cytospin, were classified as not having CNS disease. Traumatic tap (RBC ≥ 10 /µL) was registered but did not influence the classification of CNS disease.\u003c/p\u003e\u003cp\u003eExtramedullary disease was defined as AML occurring at sites outside the bone marrow (BM) and CNS, such as skin, orbit, etc.\u003c/p\u003e\u003ch2\u003e2. Patients\u003c/h2\u003e\u003cp\u003eChildren and adolescents between 0 and 19 years of age with de novo AML were included in the NOPHO-DBH AML2012 protocol. Exclusion criteria were Down syndrome, acute promyelocytic leukemia, bone marrow failure syndromes, and secondary AML. In addition, patients with isolated CNS myeloid sarcoma were excluded from analysis. Enrollment of patients commenced in March 2013, encompassing participants from the Nordic countries (Denmark, Finland, Iceland, Norway, Sweden) and Baltic countries (Estonia, Latvia, Lithuania), as well as Belgium, Hong Kong, and The Netherlands. By May 2014, all countries, except for Hong Kong (which began in June 2016), had initiated the protocol. AML2012 included two randomizations, with some countries (Iceland and the Baltic countries) opting not to participate in the randomization process. Patients who did not undergo randomization were included in an observation cohort. Subsequently, Israel joined in 2016 and Spain in 2017, both without participating in the randomizations. The randomized comparison of mitoxantrone and liposomal daunorubicin (DNX, R1) came to an early close in October 2017, as DNX production was discontinued [3]. A second randomization (R2), focusing on the second induction (ADxE vs FLADx), reached its recruitment target of 300 patients in July 2021. The present study reports on all randomized and observational patients included until July 2023.\u003c/p\u003e\u003cp\u003eThe study was approved by competent authorities and ethical review boards in each country. Informed consent and/or assent, were acquired from patients and guardians in accordance with the Declaration of Helsinki. The trial was registered with the European Medical Agency (EUDract 2012-002934-35), and on \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ewww.clinicaltrials.gov\u003c/a\u003e\u003c/span\u003e\u003cspan address=\"http://www.clinicaltrials.gov\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (NCT01828489).\u003c/p\u003e\u003ch3\u003e3. Treatment\u003c/h3\u003e\u003cp\u003ePatients were stratified into either the standard-risk (SR) or high-risk (HR) group. Response was assessed by MRD measurement using flow cytometry. The HR group comprised patients with ≥ 15% leukemic cells in the bone marrow (BM) after the 1st induction and/or ≥ 0.1% after the 2nd induction. Additionally, patients with \u003cem\u003eFLT3\u003c/em\u003e-ITD mutation without concurrent \u003cem\u003eNPM1\u003c/em\u003e mutation were classified into the HR group, irrespective of treatment response. All patients received two induction courses, with randomization in each course. SR group patients received three consolidation courses with high-dose cytarabine, except for those with inv(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e) who received only two. HR patients were scheduled for hematopoietic stem cell transplantation (HSCT) with the best available donor after one consolidation course. An overview of the therapy used in the AML2012 study is shown in Supplemental data.\u003c/p\u003e\u003cp\u003eThe protocol advised to perform a lumbar puncture (LP) on the sixth day of treatment, following 5 days of VP16 treatment, to minimize the risk of CNS bleeding.\u003c/p\u003e\u003cp\u003ePatients without CNS disease and no malignant cells in cerebrospinal fluid (CNS1) received one IT-methotrexate (MTX) injection on day 6 of the first course and at the beginning of subsequent courses. If IT-MTX was administered alongside diagnostic procedures, the day 6 injection was omitted. CNS1 patients did not require additional CSF cytology evaluations.\u003c/p\u003e\u003cp\u003ePatients with CNS2 (cytospin positive for leukemic cells with \u0026lt; 5 WBC/mm\u003csup\u003e3\u003c/sup\u003e) had the same IT treatment as CNS1 but were evaluated with an LP on day 22 after course one. If the results were negative, they were treated as patients without CNS disease.\u003c/p\u003e\u003cp\u003ePatients with CNS disease received age-adjusted triple IT (MTX, prednisone, cytarabine) injections twice weekly until the CSF was free from blasts followed by two additional injections. A minimum of four injections were given. CSF cytology was then evaluated on day 22 after the first course. Thereafter one triple IT was given at the start of each course. Cranial irradiation was not given. If cytology remained positive before the first consolidation course, the patient was regarded as refractory.\u003c/p\u003e\u003cp\u003ePatients with CNS disease with focal symptoms without malignant blasts in CSF received triple IT twice weekly for two weeks (i.e. a total of four injections) and then one triple IT injection with each course. A persistent mass present on MRI after two induction courses required a biopsy to check for viable cells.\u003c/p\u003e\u003cp\u003eCNS relapse was defined as the presence of leukemic cells in CSF cytospin with ≥ 5 WBC/µL or the detection of a tumor mass in the CNS exhibiting identical or very similar characteristics on biopsy, including morphology, immunophenotype, and cytogenetic analysis, as the original malignant cells.\u003c/p\u003e\u003cp\u003eAll treatment details, including diagnostic measures, response evaluation, toxicity, and outcome were registered in the AML 2012 database from which the data were extracted.\u003c/p\u003e\n\u003ch3\u003eStatistical Methods\u003c/h3\u003e\n\u003cp\u003eDifferences in proportions were assessed with the chi-squared test. Mann-Whitney test was used to compare medians. Overall survival was defined as the time from entry until death of any cause. Event-free survival was defined as the time from entry until death, resistant disease, relapse, or second malignant neoplasm. All estimates are given at five years. Induction death was defined as death occurring before final BM evaluation after induction 2. Survival curves were constructed according to the method of Kaplan-Meier and 95% confidence intervals (Cis) calculated according to Link (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). Cumulative incidence of relapse (CIR) was calculated using competing risk analysis according to Fine and Gray. Competing events in the analysis were resistant disease, early death, death in CR1, and second malignant neoplasm (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). To estimate hazard ratios (HzRs) for univariate and multivariate models of EFS and OS, Cox proportional hazards models were used, and competing risk regression models were used to estimate HzR for CIR (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e) (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Analyses were performed with SPSS v29 (IBM SPSS Statistics) or R v4.0.3 (R Foundation).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003ePatient characteristics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOut of the 931 eligible patients registered on AML2012, data for CNS status were available for 92\u003cspan dir=\"RTL\"\u003e2\u003c/span\u003e patients. Among these, 102 (10.9%) had CNS disease at diagnosis. Table 1 illustrates the characteristics of all patients.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe median observation time for patients alive was 49.5 months (range 2-131). Patients with CNS disease were younger compared to those without CNS disease (median 3.5 [range 0-17] vs. 8 years [0-18], P=0.001) and 36.3% of children with CNS disease were below 2 years of age. Patients with CNS disease demonstrated a higher median WBC (56.1 x10\u003csup\u003e9\u003c/sup\u003e/L [range: 1.5-517] compared to 18.7 x10\u003csup\u003e9\u003c/sup\u003e/L [range: 0.3-889] P \u0026lt; 0.001) and a higher frequency of extramedullary disease (30.4% vs. 11.3%, P \u0026lt; 0.001). The only cytogenetic aberration that was over-represented in patients with CNS disease was inv(16) (P \u0026lt; 0.001).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAmong the 102 patients with CNS disease, 33 (32.3%) were categorized as CNS disease based on clinical signs of CNS leukemia (such as facial nerve palsy or eye involvement) or radiographic evidence of an intracranial, intradural mass indicative of a chloroma. These patients did not have blasts in the CSF, (3 patients with no CSF data). Fifty-eight patients (56.8%) were classified as CNS disease solely due to having \u0026ge; 5 WBCs in the CSF along with the presence of blasts. The remaining 11 patients exhibited both clinical or radiological findings and \u0026ge; 5 WBCs with blasts.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatient outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor all patients, EFS\u003csub\u003e5y\u003c/sub\u003e and OS\u003csub\u003e5y\u003c/sub\u003e were 63.5% (CI 60.1-66.9) and 79.4% (CI 76.6-82.3). Figure 1 shows EFS and OS for patients with and without CNS disease. There was no significant difference in EFS in cases with (71.5% [CI 61.9-81.1]) or without (62.7% [CI 59.0-66.3], P=0.14) CNS disease, and similarly, no significant difference was observed for OS (81.4% [CI 73.3-89.5] vs 79.3% [CI 76.3-82.4], P=0.54). Furthermore, subgroup analyses of SR and HR groups exhibited no statistically significant differences for either EFS or OS as shown in Table 2A. Table 2B presents the treatment response. After two inductions, over 90% of patients achieved CR, both in the CNS positive and the CNS negative group. There was no difference in the distribution of risk groups between patients with and without CNS disease. Six patients with refractory disease had CNS disease at diagnosis. However, none of them failed to respond within the CNS, thus giving a complete CNS response in all cases.\u003c/p\u003e\n\u003cp\u003eThe CIR\u003csub\u003e5y\u003c/sub\u003e was significantly lower for patients with CNS disease compared to those without (15.6% [CI\u0026nbsp;8.6-24.4]\u0026nbsp;vs. 26.5% [CI 23.3-29.9], p=0.023). The difference remained significant (HzR 0.50 [CI 0.28-0.88], P=0.017) in a regression model including sex, genetic subtype, MRD after course 1, and log(WBC).\u0026nbsp;\u003cbr\u003e\u0026nbsp;Among all relapses, 1 out of 102 (0.9%) with CNS disease and 6 out of 820 (0.7%) without experienced relapse in CNS with or without BM involvement. Thus, CNS relapse was not more frequent in patients with CNS disease at primary diagnosis.\u003c/p\u003e\n\u003cp\u003eUnivariable analysis (Table 3A) showed that MRD after course 1 was strongly predictive of EFS and OS. Patients not achieving MRD \u0026lt;0.1% had significantly lower EFS (HzR 2.19 [CI 1.75-2.74], P\u0026lt;0.001)) and OS (HzR 2.57 [1.89-3.51], P\u0026lt;0.001) compared to those who had MRD \u0026lt;0.1%. The presence of CNS disease did not significantly impact EFS or OS (HzR 0.74 [CI 0.50-1.11] p=0.13 and HzR 0.94 [CI 0.57-1.55], p=0.81 respectively). Female sex was associated with lower OS but not EFS, and higher WBC count, both categorized and continuous, was associated with poorer EFS but not OS. The gene rearrangements/mutations \u003cem\u003eFLT3\u003c/em\u003e-ITD/\u003cem\u003eNPM1\u003c/em\u003ewt and \u003cem\u003eKMT2A\u003c/em\u003e rearrangement other than \u003cem\u003eKMT2A\u003c/em\u003e::\u003cem\u003eMLLT3\u003c/em\u003e were associated with lower EFS, while \u003cem\u003eRUNX1\u003c/em\u003e::\u003cem\u003eRUNX1T1\u003c/em\u003e, \u003cem\u003eCBFB\u003c/em\u003e::\u003cem\u003eMYH11\u003c/em\u003e, and \u003cem\u003eNPM1\u003c/em\u003emut were associated with better OS.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMultivariate Cox regression analysis for EFS and OS based only on diagnostic parameters is summarized in Table 3B. It confirmed that CNS disease did not significantly affect EFS (HR 0.8 [0.53-1.21], p=0.29) or OS (HR 1.09 [0.65-1.82], p=0.76). Female sex was associated with lower OS (HR 1.46 [1.07-1.98], p=0.016) while higher log(WBC) at diagnosis negatively impacted EFS (HR 1.29, p=0.004). \u003cem\u003eRUNX1\u003c/em\u003e::\u003cem\u003eRUNX1T1\u003c/em\u003e, \u003cem\u003eCBFB\u003c/em\u003e::\u003cem\u003eMYH11,\u003c/em\u003e and \u003cem\u003eNPM1\u003c/em\u003emut were associated with significantly better OS\u003cem\u003e\u0026nbsp;\u003c/em\u003ewhereas\u003cem\u003e\u003cspan dir=\"RTL\"\u003e\u0026nbsp;\u003c/span\u003eFLT3\u003c/em\u003e-ITD with wild-type \u003cem\u003eNPM1\u003c/em\u003e, \u003cem\u003eKMT2A\u003c/em\u003e rearrangements other than \u003cem\u003eKMT2A\u003c/em\u003e::\u003cem\u003eMLLT3,\u0026nbsp;\u003c/em\u003eand the group with other aberrations, were associated with lower EFS but not with OS.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWhen introducing response to treatment as an additional parameter in the multivariate Cox regression analysis (Table 3C), failure to achieve MRD \u0026lt;0.1% after course 1 emerged as the strongest factor associated with lower EFS (HzR 1.98 [1.56-2.51], p\u0026lt;0.001) and OS (HzR 2.38 [1.72-3.31], p\u0026lt;0.001) Female sex remained associated with worse OS (HzR 1.52 [CI 1.12-2.06], P=0.008) and log(WBC) with lower EFS (HzR 1.21 [CI 1.01-1.44], P=0.037). The genetic subtypes \u003cem\u003eRUNX1\u003c/em\u003e::\u003cem\u003eRUNX1T1\u003c/em\u003e, \u003cem\u003eCBFB\u003c/em\u003e::\u003cem\u003eMYH11,\u003c/em\u003e and \u003cem\u003eNPM1\u003c/em\u003emut remained significantly associated with better OS\u003cem\u003e\u0026nbsp;\u003c/em\u003ewhereas\u003cem\u003e\u0026nbsp;FLT3\u003c/em\u003e-ITD with wild-type \u003cem\u003eNPM1\u003c/em\u003e, \u003cem\u003eKMT2A\u003c/em\u003e rearrangements other than \u003cem\u003eKMT2A\u003c/em\u003e::\u003cem\u003eMLLT3\u0026nbsp;\u003c/em\u003eand the group with other aberrations, had significantly lower EFS but not OS.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe AML2012 protocol has included 931 patients and demonstrated some of the best overall results in pediatric AML with an EFS\u003csub\u003e5y\u003c/sub\u003e of 63.5%, and OS\u003csub\u003e5y\u003c/sub\u003e of 79.4%. We have attributed these improved results to intensive response-guided induction and the introduction of risk stratification primarily based on flow cytometric evaluation of response during and at the end of induction therapy.\u003c/p\u003e \u003cp\u003eApart from skin and orbital involvement, extramedullary leukemia in pAML most commonly affects the CNS (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Previously, CNS involvement was reported to range from 6\u0026ndash;29%. However, recent studies, have shown a narrower range of 8\u0026ndash;16% (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e), and our large cohort showed a frequency of 10.9%. Since some patients underwent a lumbar puncture (LP) only on the sixth day after beginning treatment, it is possible that malignant cells had already been cleared from the CSF, potentially leading to an underestimation of CNS disease. However, there was no difference in the frequency of CNS disease in patients with early lumbar puncture compared to those where the procedure was performed after day 5 from starting therapy (data supplement).\u003c/p\u003e \u003cp\u003eIn our study, the frequency of CNS disease was 17% in patients below two years at diagnosis which was higher than in the other age groups in which the frequency was 8\u0026ndash;10% also in adolescents 15\u0026ndash;17 years. Children with CNS disease also had higher WBC counts and more frequent AML with inv(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). These risk factors have been previously observed in pediatric studies (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e)(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e)(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). In adult patients, a lower occurrence of CNS leukemia is reported. A retrospective analysis of 3,240 adult patients diagnosed with de-novo AML between 1980 and 2008 across 11 clinical trials revealed that 36 patients (1.1%) had CNS disease at diagnosis, with incidence rates ranging from 0\u0026ndash;4.2% among trials(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). To some extent, this lower frequency may depend on that lumbar puncture is not always performed at diagnosis in adults.\u003c/p\u003e \u003cp\u003ePrevious studies conducted in pediatric cohorts have reached varying conclusions regarding the prognostic significance of CNS involvement at diagnosis. While the majority of studies suggest that there is no significant difference in EFS and OS between cases with CNS disease and those without (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e)(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e), some studies have indicated an increased risk of relapse(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e), especially for isolated CNS relapse(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e)(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e)(\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMultivariable Cox regression analysis (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e3\u003c/span\u003eB), both when based on diagnostic parameters alone (CNS involvement, sex, WBC, and genetic subtypes) as well as including treatment response in the model, failed to demonstrate any significant effect of CNS disease on both EFS and OS. In contrast, failure to achieve MRD\u0026thinsp;\u0026lt;\u0026thinsp;0.1% after the first induction course is strongly associated with both decreased EFS and OS (HzR 2.19 CI 1.75\u0026ndash;2.74 and 2.57 CI 1.89\u0026ndash;3.51, respectively). In the full regression, other factors associated with decreased EFS were high WBC and the genetic subtypes \u003cem\u003eFLT3\u003c/em\u003e-ITD, \u003cem\u003eKMT2A\u003c/em\u003e rearrangements other than \u003cem\u003eKMT2A\u003c/em\u003e::\u003cem\u003eMLLT3\u003c/em\u003e, and the large group with other aberrations. The latter group includes patients with potential poor risk aberrations such as \u003cem\u003eCBFA2T3\u003c/em\u003e::\u003cem\u003eGLIS2\u003c/em\u003e, \u003cem\u003eNUP98\u003c/em\u003e translocations, del(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e), and del (5q). AML with \u003cem\u003eRUNX1\u003c/em\u003e::\u003cem\u003eRUNX1T1\u003c/em\u003e, \u003cem\u003eCBFB::MYH11\u003c/em\u003e, and \u003cem\u003eNPM1\u003c/em\u003emut were associated with better OS whereas, perhaps a bit surprisingly and unexplained, female sex with decreased OS (HzR 1.42 CI 1.04\u0026ndash;1.92).\u003c/p\u003e \u003cp\u003eThe rate of CNS relapse in pAML patients with CNS disease at diagnosis varies significantly across different study groups(\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). European studies have consistently reported a higher CIR for CNS relapse in these patients (8% vs. 3%, respectively) [8][9]. In reports from Children\u0026rsquo;s Oncology Group (COG), CNS relapse rates were notably higher in patients classified as CNS3 (17.7%) and CNS2 (11.7%) compared to CNS1 patients (3.9%) [11]. However, EFS was around 53% in these studies suggesting that the treatment efficacy was lower than for AML2012 (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e)(\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Similarly, the French ELAM02 protocol reported elevated relapse rates in patients with CNS disease, particularly for combined relapses (26.1% vs. 10% )(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Despite the increased rate of CNS relapses, these studies have not shown a significant decrease in overall survival in patients with CNS disease(\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Although not significantly associated with EFS, we somewhat surprisingly found lower CIR in patients with CNS disease (16.5% vs 26.5%). This apparent discrepancy may be explained by the fact that there indeed was a trend for higher EFS in patients with CNS disease (71.5% vs 62.7%, P\u0026thinsp;=\u0026thinsp;0.14) and slightly more early deaths for CNS disease. However, one can speculate if the additional IT therapy can have systemic effects leading to a decreased relapse rate.\u003c/p\u003e \u003cp\u003eIn the European studies, the indications for HSCT in first complete remission (CR) varied significantly between study groups, and no clear data exist on transplantation rates for patients with and without CNS involvement. The AIEOP group reported a 68% HSCT rate, while for BFM, DCOG/BSPHO, and NOPHO, only 11.5% of patients with CNS disease underwent HSCT(\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e)(\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). In the French ELAM02 trial, 30.7% of cases with CNS involvement and 30.3% without received HSCT after achieving CR, showing no significant difference between the two groups. In our cohort, a relatively low proportion of 22% of patients were treated with HSCT in first remission, and patients with CNS disease did not undergo HSCT more frequently. A similar distribution of risk groups is also observed in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e2\u003c/span\u003eB.\u003c/p\u003e \u003cp\u003ePreviously, the BFM administered preventive radiation therapy to children with AML (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). However, due to severe long-term side effects (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e) and comparable outcomes to treatment without radiation, the current strategy for managing and preventing CNS disease in pAML relies on intensive systemic chemotherapy, mainly high-dose cytarabine, supplemented by IT treatment (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Despite the use of IT-Cytarabine or triple IT for CNS prophylaxis among most groups (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e) (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e), the NOPHO group has consistently utilized IT-Methotrexate for many years (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Our protocol gave a frequency of CNS relapse of under 1%. Considering that adults typically do not receive IT chemotherapy prophylaxis unless presenting with CNS symptoms, our findings prompt a reassessment of the necessity of CNS prophylaxis for pediatric patients without initial CNS involvement. It might be that high-dose cytarabine in consolidation is sufficient for these patients, eliminating the necessity for IT therapy. Ideally, this should be tested in a randomized setting but given the low numbers of CNS events, this may be unfeasible. On the other hand, if intensified IT therapy in patients with CNS disease contributes to a lower relapse rate, one could speculate that this might be of benefit even for patients without CNS disease.\u003c/p\u003e \u003cp\u003eThe NOPHO-DBH AML2012 protocol recommended an LP to be performed on the sixth day of treatment, following five days of VP16 therapy, to reduce the risk of CNS bleeding. The effect of the timing of the diagnostic LP on the detection of CNS disease and the frequency of traumatic taps was assessed. The results indicated that the timing of the LP, whether conducted before or after day 5, did not significantly influence the detection rate of CNS disease or the incidence of traumatic taps. This suggests that VP16 administration during the early treatment phase does not compromise the diagnostic accuracy of LP for CNS disease (Supplementary data).\u003c/p\u003e \u003cp\u003eTraumatic LPs, characterized by \u0026ge;\u0026thinsp;10 RBC/\u0026#120583;L, raise concerns about introducing leukemic cells into CSF at initial diagnosis. However, studies by COG and European groups, including AIEOP, BFM, DCOG/BSPHO, and NOPHO found no significant differences in survival or treatment outcomes between traumatic and atraumatic LPs (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e)(\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). These findings suggest that a traumatic tap at diagnosis does not lead to adverse outcomes. However, it is important to note that most of these patients were classified with CNS disease and received additional IT therapy. When preparing the AML2012 protocol, there was no strong evidence indicating that the presence of a low number of blasts (CNS2) affected the outcome (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)(\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). Therefore, patients with CNS2 did not receive any additional IT treatment and, although registering traumatic tap, the presence of blasts was not documented if the WBC count was \u0026lt;\u0026thinsp;5/\u0026micro;L in CSF. When comparing EFS and OS of all patients as well as for those without CNS involvement with or without traumatic tap we found no difference in outcome (Supplementary data). Since the CNS relapse rate in our protocol was low, it does not appear to be influenced by traumatic tap or by a small number of leukemic cells in the CSF and thus it seems not justifiable to treat them with intensified IT therapy.\u003c/p\u003e \u003cp\u003eIn conclusion, in this extensive multicenter study, children diagnosed with AML and CNS disease tended to be younger, with elevated WBC counts and a higher frequency of inv(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). However, CNS disease did not have an impact on CR rate, EFS, or OS. Additionally, patients with CNS disease at diagnosis tended to have a lower relapse rate, with very few relapses involving the CNS. With the treatment, including intensified IT therapy, and risk-adapted treatment stratification, used in AML2012, CNS disease at diagnosis of pAML is not an adverse prognostic factor.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eData-sharing statement\u003c/h2\u003e\n\u003cp\u003eRequests for access to data used in this article for research purposes can be made to the senior author.\u003c/p\u003e\n\u003ch2\u003eDisclosures\u003c/h2\u003e\n\u003cp\u003eNo conflicts of interest to disclose.\u003c/p\u003e\n\u003ch2\u003eContributions\u003c/h2\u003e\n\u003cp\u003eNAC, DC, BDM, JMFN, HH, KJ, GK, ZK, OGJ, BL, JP, RP, CJP, KS, BZ, UNN, AT and JA designed the research study.\u003c/p\u003e\n\u003cp\u003eNAC, DC, BDM, JMFN, HH, KJ, KLJ-D, GK, ZK, OGJ, BL, MM-K, JP, RP, CJP, KS, BZ, and JA obtained patients\u0026rsquo; consent and collected clinical data.\u003c/p\u003e\n\u003cp\u003eNAC, UNN, AT, and JA analyzed the data. NAC and JA wrote the paper.\u003c/p\u003e\n\u003cp\u003eAll authors reviewed and approved the final manuscript.\u003c/p\u003e\n\u003ch2\u003eAcknowledgment\u003c/h2\u003e\n\u003cp\u003eThe study was financed by grants from the Swedish Children\u0026rsquo;s Cancer Foundation and the Swedish state under the agreement between the Swedish government and the county councils, the ALF agreement (ALFGBG-966256).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAplenc R, Meshinchi S, Sung L, Alonzo T, Choi J, Fisher B, et al. Bortezomib with standard chemotherapy for children with acute myeloid leukemia does not improve treatment outcomes: a report from the Children\u0026rsquo;s Oncology Group. Haematologica. 2020;105(7):1879\u0026ndash;1886.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eReinhardt D, Antoniou E, Waack K. Pediatric Acute Myeloid Leukemia-Past, Present, and Future. J Clin Med. 2022;11(3).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTierens A, Arad-Cohen N, Cheuk D, De Moerloose B, Fernandez Navarro JM, Hasle H, et al. Mitoxantrone Versus Liposomal Daunorubicin in Induction of Pediatric AML With Risk Stratification Based on Flow Cytometry Measurement of Residual Disease. J Clin Oncol. 2024;42(18):2174\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbbott BL, Rubnitz JE, Tong X, Srivastava DK, Pui CH, Ribeiro RC, et al. Clinical significance of central nervous system involvement at diagnosis of pediatric acute myeloid leukemia: A single institution\u0026rsquo;s experience. Leukemia. 2003;17(11):2090\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFelix A, Leblanc T, Petit A, Nelkem B, Bertrand Y, Gandemer V, et al. Acute Myeloid Leukemia with Central Nervous System Involvement in Children: Experience from the French Protocol Analysis ELAM02. J Pediatr Hematol Oncol. 2018;40(1):43\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGanzel C, Lee JW, Fernandez HF, Paietta EM, Luger SM, Lazarus HM, et al. CNS involvement in AML at diagnosis is rare and does not affect response or survival: data from 11 ECOG-ACRIN trials. Blood Adv. 2021;5(22):4560\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnston DL, Alonzo TA, Gerbing RB, Lange BJ, Woods WG. The presence of central nervous system disease at diagnosis in pediatric acute myeloid leukemia does not affect survival: A children\u0026rsquo;s oncology group study. Pediatr Blood Cancer. 2010;55(3):414\u0026ndash;20.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCreutzig U, Dworzak MN, Zimmermann M, Reinhardt D, Sramkova L, Bourquin JP, et al. Characteristics and outcome in patients with central nervous system involvement treated in European pediatric acute myeloid leukemia study groups. Pediatr Blood Cancer. 2017;64(12):1\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSt\u0026oslash;ve HK, Sandahl JD, Abrahamsson J, Asdahl PH, Forestier E, Ha SY, et al. Extramedullary leukemia in children with acute myeloid leukemia: A population-based cohort study from the Nordic Society of Pediatric Hematology and Oncology (NOPHO). Pediatr Blood Cancer. 2017;64(12):1\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePui CH, Howard SC. Current management and challenges of malignant disease in the CNS in paediatric leukaemia. Lancet Oncol. 2008;9(3):257\u0026ndash;68.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnston DL, Alonzo TA, Gerbing RB, Aplenc R, Woods WG, Meshinchi S, et al. Central nervous system disease in pediatric acute myeloid leukemia: A report from the Children\u0026rsquo;s Oncology Group. Pediatr Blood Cancer. 2017;64(12):1\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZeller B, Arad-Cohen N, Cheuk D, De Moerloose B, Navarro JMF, Hasle H, et al. Management of hyperleukocytosis in pediatric acute myeloid leukemia using immediate chemotherapy without leukapheresis: results from the NOPHO-DBH AML 2012 protocol. Haematologica. 2024;109(9):2873\u0026ndash;83.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLink CL. Confidence intervals for the survival function using Cox\u0026rsquo;s proportional-hazard model with covariates. Biometrics. 1984;40(3):601\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFine JP, Gray RJ. A Proportional Hazards Model for the Subdistribution of a Competing Risk. J Am Stat Assoc. 1999;94(446):496\u0026ndash;509.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCox DR. Regression Models and Life-Tables. J R Stat Soc Ser B Stat Methodol. 1972;34(2):187\u0026ndash;202.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDusenbery KE, Howells WB, Arthur DC, Alonzo T, Lee JW, Kobrinsky N, et al. Extramedullary leukemia in children with newly diagnosed acute myeloid leukemia: a report from the Children\u0026rsquo;s Cancer Group. J Pediatr Hematol Oncol. 2003;25(10):760\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnston DL, Alonzo TA, Gerbing RB, Lange BJ, Woods WG. Superior outcome of pediatric acute myeloid leukemia patients with orbital and CNS myeloid sarcoma: A report from the Children\u0026rsquo;s Oncology Group. Pediatr Blood Cancer. 2012;58(4):519\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRozovski U, Ohanian M, Ravandi F, Garcia-Manero G, Faderl S, Pierce S, et al. Incidence of and risk factors for involvement of the central nervous system in acute myeloid leukemia. Leuk Lymphoma. 2015;56(5):1392\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnston DL, Alonzo TA, Gerbing RB, Lange BJ, Woods WG. Risk factors and therapy for isolated central nervous system relapse of pediatric acute myeloid leukemia. J Clin Oncol. 2005;23(36):9172\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGruber TA, Zwaan CM. Central nervous system disease in pediatric acute myeloid leukemia. Pediatr Blood Cancer. 2017;64(12):1\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGamis AS, Alonzo TA, Meshinchi S, Sung L, Gerbing RB, Raimondi SC, et al. Gemtuzumab ozogamicin in children and adolescents with de novo acute myeloid leukemia improves event-free survival by reducing relapse risk: Results from the randomized phase iII children\u0026rsquo;s oncology group Trial AAML0531. J Clin Oncol. 2014;32(27):3021\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCooper TM, Franklin J, Gerbing RB, Alonzo TA, Hurwitz C, Raimondi SC, et al. AAML03P1, a pilot study of the safety of gemtuzumab ozogamicin in combination with chemotherapy for newly diagnosed childhood acute myeloid leukemia: A report from the Children\u0026rsquo;s Oncology Group. Cancer. 2012;118(3):761\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDe Moerloose B, Reedijk A, de Bock GH, Lammens T, de Haas V, Denys B, et al. Response-guided chemotherapy for pediatric acute myeloid leukemia without hematopoietic stem cell transplantation in first complete remission: Results from protocol DB AML-01. Pediatr Blood Cancer. 2019;66(5):e27605.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbrahamsson J, Forestier E, Heldrup J, Jahnukainen K, J\u0026oacute;nsson OG, Lausen B, et al. Response-guided induction therapy in pediatric acute myeloid leukemia with excellent remission rate. J Clin Oncol Off J Am Soc Clin Oncol. 2011;29(3):310\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCreutzig U, Zimmermann M, Bourquin JP, Dworzak MN, Fleischhack G, von Neuhoff C, et al. CNS irradiation in pediatric acute myleoid leukemia: Equal results by 12 or 18 Gy in studies AML-BFM98 and 2004. Pediatr Blood Cancer. 2011;57(6):986\u0026ndash;92.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKrull KR, Li C, Phillips NS, Cheung YT, Brinkman TM, Wilson CL, et al. Growth hormone deficiency and neurocognitive function in adult survivors of childhood acute lymphoblastic leukemia. Cancer. 2019;125(10):1748\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnston DL, Alonzo TA, Gerbing RB, Aplenc R, Woods WG, Meshinchi S, et al. The Effect of Traumatic Diagnostic Lumbar Puncture in De Novo Pediatric Acute Myeloid Leukemia - a Report from the Children\u0026rsquo;s Oncology Group. Blood. 2016;128(22):4016.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCreutzig U, Van Den Heuvel-Eibrink MM, Gibson B, Dworzak MN, Adachi S, De Bont E, et al. Diagnosis and management of acute myeloid leukemia in children and adolescents: Recommendations from an international expert panel. Blood. 2012;120(16):3167\u0026ndash;205.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 to 3 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"leukemia","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"leu","sideBox":"Learn more about [Leukemia](http://www.nature.com/leu/)","snPcode":"41375","submissionUrl":"https://mts-leu.nature.com/cgi-bin/main.plex","title":"Leukemia","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5449535/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5449535/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Central nervous system disease (CNS3) \u0026nbsp;in pediatric acute myeloid leukemia (pAML) is reported in 6% to 29% of cases. However, its impact on event-free survival (EFS) and overall survival (OS) remains uncertain. This study evaluates the effect of CNS involvement at diagnosis on relapse and survival in patients treated on the NOPHO-DBH AML2012 protocol.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData from 931 pediatric AML patients in the NOPHO-DBH AML2012 protocol were analyzed, comparing outcomes, relapse rates, and survival between those with and without CNS disease. CNS-directed therapy included intensified intrathecal chemotherapy without irradiation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eOf 922 patients with available CNS status, 10.9% had CNS3 at diagnosis. CNS3 patients were younger (median age 3.5 vs. 8 years,P=0.001) with higher white blood cell counts (56.1x10\u003csup\u003e9\u003c/sup\u003e/L vs 18.7x10\u003csup\u003e9\u003c/sup\u003e/L,P\u0026lt;0.001) and higher frequency of other extramedullary disease (30.4% vs 11.3%,P\u0026lt;0.001) and inv(16)(P\u0026lt;0.001).\u003c/p\u003e\n\u003cp\u003eEFS\u003csub\u003e5y\u003c/sub\u003e was 71.5% for CNS-positive patients vs. 62.7% for CNS-negative (p=0.14), and OS\u003csub\u003e5y \u003c/sub\u003ewas 81.4% vs. 79.3% (p=0.54). Patients with CNS disease had a lower cumulative incidence of relapse (15.6% vs 26.5%,P=0.023), and CNS relapse occurred in 0.9% and 0.7% of patients with and without CNS disease.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e CNS disease at diagnosis in pAML does not adversely affect survival or treatment response.\u003c/p\u003e","manuscriptTitle":"Central Nervous System Disease and Outcome in Pediatric Acute Myeloid Leukemia: Results from NOPHO-DBH AML2012 Trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-18 08:19:49","doi":"10.21203/rs.3.rs-5449535/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"revise","date":"2025-02-24T14:22:12+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"This content is not available.","date":"2025-01-27T10:18:51+00:00","index":3,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2025-01-08T17:40:36+00:00","index":3,"fulltext":"This content is not available."},{"type":"editorInvitedReview","content":"This content is not available.","date":"2024-12-01T17:00:55+00:00","index":1,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2024-11-17T22:06:43+00:00","index":2,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2024-11-17T10:55:40+00:00","index":1,"fulltext":"This content is not available."},{"type":"reviewersInvited","content":"","date":"2024-11-14T21:51:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-11-14T12:16:41+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-11-14T12:16:27+00:00","index":"","fulltext":""},{"type":"submitted","content":"Leukemia","date":"2024-11-13T21:26:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"leukemia","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"leu","sideBox":"Learn more about [Leukemia](http://www.nature.com/leu/)","snPcode":"41375","submissionUrl":"https://mts-leu.nature.com/cgi-bin/main.plex","title":"Leukemia","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"06567919-3569-4a9e-a982-ab6fca626779","owner":[],"postedDate":"December 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":40287171,"name":"Health sciences/Medical research/Clinical trial design/Clinical trials/Phase III trials"},{"id":40287172,"name":"Health sciences/Diseases/Haematological diseases/Haematological cancer/Leukaemia/Acute myeloid leukaemia"},{"id":40287173,"name":"Health sciences/Diseases/Cancer/Cancer therapy/Chemotherapy"}],"tags":[],"updatedAt":"2025-02-24T14:26:01+00:00","versionOfRecord":[],"versionCreatedAt":"2024-12-18 08:19:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5449535","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5449535","identity":"rs-5449535","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}