Long-term prognostic value of staging surgery for high-intermediate-risk and high-risk endometrial cancer

Endometrial cancer (EC) represents a major global health burden, ranking seventh among the most frequently diag - nosed cancers in women worldwide and fourth among European women [1]. Approximately 420,300 new cases of EC were reported globally in 2022, of which nearly 125,000 occurred within Europe [2, 3]. Both the incidence and mor- tality rates of EC have continued to increase, largely attrib - utable to the growing prevalence of established risk factors [4–6]. The World Health Organization (WHO) classifies EC into several main histologic tumour subtypes, including endometrioid, serous, and clear cell carcinoma (CCC), undifferentiated (UC) and dedifferentiated carcinomas, carcinosarcoma (CS), and mixed carcinoma [ 1, 5, 6]. The Cornelis G. Gerestein [email protected] 1 Department of Gynecologic Oncology, University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, The Netherlands 2 Department of Radiotherapy, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands 3 Department of Medical Oncology, University Medical Center Utrecht, Utrecht University, 85500, 3508 GA Utrecht, The Netherlands 4 Department of Pathology, University Medical Center Utrecht, Utrecht University, 85500, 3508 GA Utrecht, The Netherlands

The prognostic relevance of surgical staging in patients with high-intermediate-risk and high-risk endometrial cancer remains uncertain. In this cohort study, we investigated the prognostic role of robot-assisted laparoscopic staging surgery among patients with clinically early-stage endometrial carcinoma at a high-intermediate-risk or high-risk for recurrence. Clinical data of women with clinically International Federation of Gynaecology and Obstetrics (FIGO) 2009 stage I–II, grade 3 endometrioid or non-endometrioid EC who were intended to undergo robot-assisted laparoscopic staging sur - gery were retrospectively collected from a single tertiary referral center. The procedure consisted of total hysterectomy with bilateral salpingo-oophorectomy, pelvic lymphadenectomy, and, when feasible, para-aortic lymphadenectomy, with additional omentectomy and peritoneal biopsies performed in a subset of cases. Survival outcomes were assessed using Kaplan–Meier analysis, with additional subgroup analyses by histological subtype. A total of 166 patients, of which 154 patients (92.8%) with FIGO 2009 stage I and 12 patients (7.2%) with FIGO 2009 stage II were included, comprising various histological subtypes, including 64 (38.6%) with endometrioid carcinoma, 52 (31.3%) with serous carcinoma, 11 (6.6%) with clear cell carcinoma, and 27 (16.3%) with carcinosarcoma. Thirty-two patients (19.3%) were reclassified as having FIGO stage disease III–IV based on final pathology. The 5-year disease-specific survival was 25.5% for upstaged patients compared with 73.1% for those who were not upstaged. Robot-assisted laparoscopic staging provides valuable prognostic information in clinically early-stage endometrial cancer with a high-intermediate-risk or high-risk of recurrence. These findings underscore the value of surgical staging in informing prognosis and guiding adjuvant treatment decisions.

Endometrial neoplasms · Robotic surgical procedures · Treatment outcome · Disease-free survival · Recurrence Received: 13 January 2026 / Accepted: 3 March 2026 © The Author(s) 2026 Long-term prognostic value of staging surgery for high-intermediate- risk and high-risk endometrial cancer Alise de Jong1  · Jasper Markus1  · Ronald P . Zweemer1  · Jacob P . Hoogendam1 · Judith M. Roesink2  · Inge O. Baas3  · Geertruida N. Jonges4 · Cornelis G. Gerestein1 1 3 Journal of Robotic Surgery (2026) 20:468 International Federation of Gynaecology and Obstetrics (FIGO) staging system further classifies EC by anatomical characteristics. In 2023, the FIGO classification system was updated to integrate molecular classification with tumour characteristics and histological subtype [7]. To further determine stage, staging surgery is recom - mended for patients with grade 3 endometrioid endome - trial carcinoma (EEC) or non-endometrioid EC [ 1, 7–9]. In staging surgery, pelvic lymph node dissection (PLND) with or without paraaortic lymph node dissection (PALND) is performed in addition to hysterectomy and bilateral salpingo-oophorectomy. In serous carcinoma (SC) and CS omentectomy and peritoneal biopsies should be considered [10]. Surgical staging plays an important role in determin - ing which patients require intensive adjuvant treatment. It provides insight into predictors of prognosis, such as lymph node status, lymphovascular space invasion (LVSI) and dept of myometrial invasion [ 11, 12]. This can guide adjuvant treatment strategies and identify patients in whom adju - vant treatment may be safely omitted. However, it remains unclear whether the prognostic information obtained through (robot-assisted laparoscopic) staging surgery has an impact on overall survival (OS), disease-specific survival (DSS) or disease-free survival (DFS) [ 13]. In this cohort study, we evaluated the prognostic role of robot-assisted laparoscopic staging (RALS) surgery among patients with clinically early-stage EC at a high-intermediate-risk or high-risk for recurrence.

All women diagnosed with clinically FIGO 2009 stage I or II, grade 3 EEC or non-endometrioid EC who were intended to treat with RALS surgery between the 1st of January, 2012, until the 31st of December, 2023, at the University Medical Center Utrecht, were retrospectively included. Patients were treated in accordance with contemporaneous national and international guidelines. Follow-up information was docu - mented in the medical files. Given the retrospective design and use of pseudonominysed data, formal informed consent was not required, as approved by the institutional review board. The primary aim is to evaluate the prognostic role of RALS among patients with clinically early-stage EC, with presumed high-intermediate-risk or high-risk for recur - rence. Main objectives are to determine in how many patients RALS resulted in upstaging to advanced FIGO stages (FIGO 2009 stage III or IV) and to determine OS, DSS, and DFS for patients in whom RALS resulted in upstaging to advanced FIGO stages III or IV and compare

to patients without upstaging. Secondary objectives are to determine which were the localisations of metastases leading to upstaging. Other

include assessing differences in OS, DSS and DFS between patients who were upstaged and those who were not for each histological subtype. Patients eligible for inclusion were 18 years old or older, with a diagnosis of primary endometrial carcinoma (grade 3 EEC, SC, CCC, CS, UC and dedifferentiated carcinomas or mixed carcinoma) confirmed by histopathological examina- tion, pre-operative early FIGO 2009 stage (defined as stage I or II) who were treated primarily with RALS surgery. Patients receiving neoadjuvant treatment prior to surgery were excluded. Relevant clinical variables, including demo- graphics, tumour characteristics, surgical treatment, and follow-up data, were obtained from electronic patient files. Risk group classification was performed in accordance with the European Society of Gynaecological Oncology/ European Society for Radiotherapy and Oncology/Euro - pean Society of Pathology (ESGO/ESTRO/ESP) guidelines of 2020 [ 14]. During the study period, complete molecu - lar classification was not routinely available. Patients with preoperative stage I grade 3 EEC and stage II EEC were classified as high-intermediate risk EC, whereas preopera - tive stage I or II EC with non-endometrioid histologies (SC, CCC, UC and dedifferentiated carcinomas, CS, or mixed carcinoma) with myometrial invasion were classified as high-risk EC. Standard preoperative imaging consisted of transvaginal ultrasonography and abdominal and thoracic computed tomography (CT). Preoperative magnetic reso - nance imaging was not routinely performed to assess for myometrial invasion. The surgical procedure regarding patients with clini - cally early-stage EC at high-intermediate- or high-risk for recurrence, performed at the UMC Utrecht has been pre - viously described [ 15]. Surgery was performed by a team of three gynaecologic oncologists using a robotic surgi - cal system (da Vinci Surgical System Si until 2017, X or Xi from 2018–2023; Intuitive Surgical, Sunnyvale, CA). RALS surgery comprised of total hysterectomy with bilat - eral salpingo-oophorectomy, PLND, and, when feasible, PAOLND. PLND included systematic excision of lym - phatic tissue along the common, external and internal iliac vessels and in the obturator fossa. PAOLND comprised excision of precaval and paracaval lymphatic tissue up to the level of the left renal vein. During this study period, the sentinel lymph node (SLN) procedure was not standard of care according to contemporaneous guidelines. In CSa, SCs or CCC histologies, omentectomy and peritoneal tis - sue sampling were performed in addition to standard stag - ing. Surgical methods used, including use of the McCartney uterine manipulator manufactures by LiNA Medical (Den - mark), remained unchanged throughout the study period. 1 3 468 Page 2 of 10 Journal of Robotic Surgery (2026) 20:468 Operation time was calculated from incision until the skin was sutured. Adjuvant treatment strategies were determined in a multidisciplinary tumour board setting in accordance with contemporary guidelines and were risk-adapted based on postoperative FIGO 2009 stage, histological subtype, tumour grade, depth of myometrial invasion, LVSI, nodal involvement, and patient-related factors. Oncological fol - low-up was conducted according to national guidelines, with visits scheduled at three-monthly intervals during the first two years after surgery, followed by six-monthly inter- vals thereafter, up to five years post-treatment. Follow-up visits alternated between the gynaecologist and the radiation oncologist or medical oncologist, and no routine CT scans or tumour marker assessments were performed. Continuous variables were described using means with standard deviation (SD) or medians with interquartile range (IQR) depending on data distribution. Categorial variables were reported as counts and percentages. Images were cre - ated with Biorender.com. OS was defined as the interval, in days, from the date of the operation to the date of death from any cause or the date of last-follow-up. DSS was defined as the interval from the date of the operation to the date of death of disease or the date of last follow-up. Non–disease deaths are censored at death for DSS. DFS was defined as the interval from the operation date until formal confirmation of recurrence at a multidisciplinary tumour board meeting, or until the most recent follow-up. Time-to-event outcomes were evaluated using Kaplan–Meier survival analysis. Statistical signifi - cance was assessed using log-rank tests with administra - tive censoring at 12, 36, and 60 months. A p-value < 0.05 was defined as statistically significant. Standard error was determined using Greenwood’s formula. Cox proportional hazards regression was performed to assess whether upstag- ing remained independently associated with survival after adjustment for confounders. Multivariable models included age, LVSI, and myometrial invasion, selected based on clin- ical relevance and univariable significance, with the number of covariates restricted to avoid overfitting. Hazard ratios (HRs) with 95% confidence intervals (CIs) were reported. All analysis, figures and plots were generated in the R statis- tical computing environment (R version 4.5.1R Core Team, 2025).

Clinical characteristics of the 166 included patients with clinically early-stage EC at a high-intermediate- or high- risk for recurrence are described in Table 1. Follow-up dura- tion was 25 months [IQR 13.0–44.8]. 160 patients (96.4%) underwent PLND. 136 patients (81.9%) underwent PALND. The median BMI was 33.96 (30.47–39.04) in the group without PALND, compared to 25.83 (29.38–23.31) in the group that underwent PALND (Table 1). Following RALS, 32/166 included patients (19.3%) were reclassified as having advanced stage FIGO III-IV disease after surgical staging and were therefore considered upstaged (Fig. 1) In total, 21/32 patients (65.6%) had meta- static lymph nodes; only 5/21 patients (23.8%) had isolated para-aortic lymph node metastasis. 5/32 patients (15.6%) had omental metastasis and 5/32 patients (15.6%) had peri- toneum metastasis. Patients were upstaged due to the fol - lowing findings: 2/32 (6.3%) because of both omental and peritoneal metastases, 3/32 (9.4%) due to omental metas - tases only, and 3/32 (9.4%) due to peritoneal metastases only. Among these eight patients, 4/8 (50%) had parametrial Table 1 Baseline characteristics of study population Characteristic Study population, n = 166 Age, years 68.50 (62.00, 73.00) BMI, kg/m2 27.48 (23.74, 31.89) Previous abdominal infection 31 (18.7%) Previous abdominal surgery 85 (51.2%) Smoking Current 18 (10.8%) Stopped over ten years ago 8 (4.8%) Stopped over five years ago 1 (0.6%) Stopped less than five years ago 5 (3.0%) Stopped 4 (2.4%) Never 130 (78.3%) Preoperative histology Endometrioid carcinoma 67 (40.4%) Serous carcinoma 58 (34.9%) Clear cell carcinoma 14 (8.4%) Carcinosarcoma 18 (10.8%) Undifferentiated carcinoma 5 (3.0%) Other 4 (2.4%) Preoperative FIGO 2009 IA 141 (84.9%) IB 13 (7.8%) II 12 (7.2%) PLND performed 160 (96.4%) PALND performed 136 (81.9%) Lymph nodes dissected, n 20 (14, 23) Omentectomy performed 108 (65.1%) Peritoneum biopsy performed 91 (54.8%) Operation time, min 230 (195, 267) Unknown 1 Blood loss, ml 100 (50, 150) Unknown 15 Statistics presented: median (interquartile range); n (%) BMI = body mass index, PLND = pelvic lymph node dissection, PALND = para-aortic lymph node dissection, ml = milliliters, min = minutes, FIGO = International Federation of Gynecology and Obstetrics 1 3 Page 3 of 10 468 Journal of Robotic Surgery (2026) 20:468 were reclassified as having advanced FIGO stages III or IV disease (Table 3). Survival analysis using Kaplan–Meier method demon - strated a statistically significant prognostic effect of upstag- ing to advanced FIGO stages III-IV following RALS on long-term survival outcomes in patients with clinically early-stage EC at a high-intermediate-risk or high-risk for recurrence. Patients reclassified as having advanced stage FIGO III or IV disease had a statistically significant worse OS (p < 0.01), DSS (p < 0.01) and DFS (p < 0.01) in contrast to patients who remained classified as early-stage disease (Fig. 2). In multivariable Cox regression adjusting for age, LVSI, and myometrial invasion, upstaging remained inde - pendently associated with worse overall survival (HR 2.77, 95% CI 1.40—5.48, p = 0.003), disease-specific survival (HR 3.21, 95% CI 1.57—6.54, p = 0.001) and disease-free survival (HR 2.06, 95% CI 1.09—3.92, p = 0.027) (Supple- mentary 2). In total, 52 patients (31.3%) had a recurrence of dis - ease. Of the 32 patients who were upstaged to advanced stage FIGO III-IV , 20 patients (62,5%) had a recurrence of disease. Of the 134 patients who remained classified as FIGO stage I-II, 32 patients (23.9%) had disease recur - rence. The median time until recurrence of these patients was 14 months (IQR 7.50–28.00). 17/32 (53.1%) patients had unifocal recurrence of disease. 3/32 patients (9.4%) had port site metastasis, all of whom had additional locations of disease recurrence. Further information on lymph node and organ recurrences in patients who remained classified as FIGO stage I-II are presented in Supplementary 3. involvement and 3 (37.5%) also had positive lymph nodes. An additional 18/32 patients (56.3%) were upstaged due to lymph node metastases, of whom 3/18 (16.7%) also showed parametrial involvement. Finally, 4/32 patients (12.5%) were upstaged due to parametrial involvement alone, 1/32 (3.1%) due to vaginal involvement, and 1/32 (3.1%) due to adnexal invasion (Table 2). The majority of patients who remained classified as early-stage FIGO stage I-II disease underwent vaginal brachytherapy (VBT) ( n = 94/134, 70.1%) postoperatively. The majority of patients who were reclassified as hav - ing advanced stage FIGO III-IV disease received external beam radiotherapy (EBRT) (n = 13/32, 40.6%). 9/32 patients (28.1%) underwent adjuvant chemotherapy. Adjuvant ther- apy was not administered in 6/32 patients(18.8%) due to rapid disease progression in two patients, refusal of adju - vant therapy in two patients who subsequently received hor- monal therapy or chemotherapy at disease relapse, another patient being judged unfit for adjuvant treatment, and fol - low-up information missing for one patient (Supplementary 1). OS rates for the 134 patients who remained classified as early-stage FIGO stages I-II were 93.4%, 82.5% and 67.5%, compared to 68%, 34.9% and 25.5% in the upstaged group at 1, 3 and 5-year follow-up, respectively ( p-value < 0.01). DSS rates in patients who remained classified as early-stage FIGO stages I-II were 93.4%, 83.4% and 73.1% at 1, 3 and 5-year follow-up, respectively ( p-value < 0.01). DSS rates did not differ from overall survival among patients who Fig. 1 Pre- and postoperative FIGO 2009 stage 1 3 468 Page 4 of 10 Journal of Robotic Surgery (2026) 20:468 risk groups, OS rates for the 94 patients who remained FIGO stages I-II at 1, 3, and 5-year follow-up were 93.1%, 79.8% and 58.6% and DSS rates were 93.1%, 81.1%, and 66.2%. OS and DSS rates for the 32 patients who were reclassified as having advanced stage FIGO III-IV did not differ from those previously reported for the entire cohort, as these patients represent the same subgroup (Table 3). In total, 47 of 126 patients (37.3%) in the combined postop - erative high-(intermediate-)risk groups had a recurrence of disease. Of the 94 patients who remained early-stage FIGO I-II, 20 patients (21.3%) had a recurrence of disease. Among patients with EEC ( n = 64), 7 patients (10.9%) were reclas - sified as having advanced stage FIGO III-IV disease follow- ing RALS (Supplementary 4). Upstaging was not associated with a significant difference for both OS (p = 0.59) and DSS (p = 0.61), in contrast with patients who remained early- stage FIGO I-II EEC. In contrast, DFS was significantly lower in the upstaged group ( p < 0.01), indicating a higher risk of recurrence without an apparent effect on long-term survival (Supplementary 5). In 90 patients with non-endometrioid carcinoma, 24 patients (26.7%) were reclassified as having FIGO stage III-IV disease following RALS (Supplementary 4). 19.2% of patients with SC (10/52), was reclassified as hav - ing advanced stage FIGO III-IV disease (Supplementary 6). Among patients with SC, those reclassified as hav - ing advanced stage FIGO III-IV disease had a statistically significantly worse OS ( p < 0.01), DSS (p < 0.01) and DFS (p < 0.01) than those who remained early stage FIGO I-II (Supplementary 7). Four patients diagnosed with CCC were reclassified as having advanced stage FIGO III-IV disease follow - ing RALS and had a statistically significantly worse OS (p < 0.01) and DSS (p < 0.01) in contrast to those remaining early stage FIGO I-II. In contrast, no significant difference in DFS was observed between the groups (p = 0.14), though these findings should be interpreted with caution due to the small subgroup size (n = 11) (Supplementary 8 & 9). 37% of patients with CS (10/27) were reclassified as hav- ing advanced stage FIGO III-IV disease following RALS (Supplementary 10) Upstaging was not associated with a significant difference in OS (p = 0.09) or DSS ( p = 0.06). In contrast, DFS was statistically significant worse in upstaged patients (p = 0.05) in contrast to those who remained clas - sified as early-stage disease, although this finding may be influenced by the limited subgroup size ( n = 27) (Supple - mentary 11). Postoperative histopathological assessment identified CS in four patients (2.4%). Other histological subtypes were diagnosed in an additional six patients (3.6%) (Table 2) This group consisted of two patients with rhabdomyosar - coma, one patient with adenosarcoma, one patient with Of the 166 included patients, risk stratification identified 34 patients (20.5%) as intermediate-risk, 32 patients (19.3%) as high-intermediate-risk and 94 patients (56.5%) as high- risk for recurrence (Table 2). This is mainly explained by the absence of preoperative MRI, resulting in 34 patients who were found to have < 50% myometrial invasion only after surgery. In three cases, the postoperative differentia - tion grade was lower than the preoperative assessment. All 32 patients who were upstaged postoperatively were classified as high-intermediate risk or high risk (32/126, 25.4%). In this combined postoperative high-(intermediate-) Table 2 Postoperative pathology characteristics of study population Characteristic Study population, n = 166 Upstaged to FIGO stage III–IV 32 (19.3%) Risk classification1 Low 3 (1.8%) Intermediate 34 (20.9%) High‑intermediate 32 (19.6%) High 94 (57.7%) Unknown 3 Postoperative histology Endometrioid carcinoma 64 (38.6%) Serous carcinoma 52 (31.3%) Clear cell carcinoma 11 (6.6%) Carcinosarcoma 27 (16.3%) Undifferentiated carcinoma 4 (2.4%) Other 6 (3.6%) Tumor free 2 (1.2%) Lymph node metastasis Yes 21 (12.7%) Micrometastasis 18 (10.7%) Macrometastasis 3 (1.8%) No 141 (84.9%) Not performed 4 (2.4%) Omental metastasis Yes 5 (3.0%) No 103 (62.0%) Not performed 58 (34.9%) Peritoneal metastasis Yes 5 (3.0%) No 86 (51.8%) Not performed 75 (45.2%) Adjuvant therapy None 25 (15.1%) Vaginal brachytherapy 95 (57.2%) External beam radiotherapy 30 (18.1%) Chemotherapy 11 (6.6%) Other 5 (3.0%) Statistics presented: median (interquartile range); n (%) ESGO = European Society of Gynaecological Oncology, ESTRO = European Society for Radiotherapy and Oncology, ESP = European Society of Pathology, FIGO = International Federa - tion of Gynecology and Obstetrics 1ESGO/ESTRO/ESP guidelines 2020 1 3 Page 5 of 10 468 Journal of Robotic Surgery (2026) 20:468 survival outcomes in multivariable Cox regression analy - ses, underscoring its prognostic significance. The question remains how this prognostic information can be translated to improved adjuvant treatment for upstaged patients and whether there are patients who should receive adjuvant therapy regardless of the results of staging surgery. Hope - fully, the molecular classification will improve surgical and adjuvant treatment strategies and provide new therapeutic targets. RALS is associated with fewer morbidities such as lymphedema and lymphoceles, compared to laparotomic staging [ 15, 18, 19]. To further reduce the morbidity of staging surgery, SLN procedure is increasingly being adopted by gynaecologic oncologists as a replacement for systematic lymphadenectomy. Various systematic reviews found that no statistically significant differences in sur - vival were observed between patients who underwent SLN and lymphadenectomy [ 20–25]. However, several of these reviews were assessed as low quality and did not explicitly describe survival outcomes of SLN in patients with EC at a high-intermediate- or high-risk for recurrence [ 26]. The SENTIREC-ENDO trial demonstrated a safe diagnostic algorithm for SLN mapping in high-risk EC [ 27]. A lim - itation however of the SLN procedure is the risk to miss isolated paraaortic metastases [28, 29]. In this study cohort 5/166 patients (3%) had isolated paraaortic metastases. PALND was not performed mainly due to technical feasibil- ity in a subset of patients (30/166, 18.1%), which could have led to missed isolated paraaortic lymph node metastasis. Although paraaortic metastasis could be missed, SLN pro - cedure uses ultrastaging which increases the likelihood of detecting lymph node metastasis [ 30, 31]. Future research may determine whether lymphadenectomy can be omitted or substituted by SLN procedure guided by preoperative molecular risk classification. Arguably SLN procedure will become the standard of care in the near future [32–34]. A strength of this study is the availability of detailed clinicopathological and surgical data, allowing for a mesonephric-like adenocarcinoma, one patient with muci - nous carcinoma, and one patient with neuroendocrine carcinoma.

This study evaluates RALS in 166 high-intermediate and high-risk EC patients resulting in 19.3% upstaging. 5-year DSS for patients who reclassified as having advanced FIGO stages III-IV following RALS was 25.5% compared to 73.1% for patients who were not upstaged. Notably, the majority of not upstaged patients underwent VBT and the majority upstaged patients underwent either EBRT or che - motherapy. During the study period, combined chemoradio- therapy was not routinely administered, as this was not our institutional standard. OS and DSS did not differ significantly between upstaged and non-upstaged patients with EEC and CS, despite a sig - nificant reduction in their DFS. This observation in patients with CS should be interpreted with caution given the lim - ited sample size ( n = 27). For patients with EEC this may be explained by the fact that the risk groups in this study differed from the current updated risk classification. This subgroup may include POLE-mutated tumours, whose generally favourable clinical course could contribute to the favourable survival outcomes reported in this study [16]. In this cohort, the recurrence rate was 31.3%, similar to the 27.4%–44.8% range reported in the PORTEC-3 study [17]. The most frequent locations of recurrence were the pelvis (11.2%, of which 3/15 patients had vaginal recurrence), peritoneum (11.2%) or lungs (7.5%). This study demonstrates that the added value of surgi - cal staging without performing molecular classification lies in the prognostic information it provides regarding patient outcomes. Especially for patients who are not upstaged after surgical staging 5-years survival rate is nearly 75%. Upstaging remained independently associated with worse Table 3 Survival rates Survival type Timepoint Study population (n = 166) Postoperative high-(intermediate-) risk group (n = 106) Not upstaged (n at risk) Upstaged (n at risk) p-value Not upstaged (n at risk) Upstaged (n at risk) p-value Overall survival 12 months 93.4% (n = 107) 68.0% (n = 1 8 ) < 0.01 93.1% (n = 7 5 ) 68.0% (n = 1 8 ) < 0.01 36 months 82.5% (n = 4 8 ) 34.9% (n = 10) < 0.01 79.8% (n = 33) 34.9% (n = 10) < 0.01 60 months 67.5% (n = 1 8 ) 25.5% (n = 3) < 0.01 58.6% (n = 12) 25.5% (n = 3) < 0.01 Disease-spe- cific survival 12 months 93.4% (n = 107) 68.0% (n = 1 8 ) < 0.01 93.1% (n = 7 5 ) 68.0% (n = 1 8 ) < 0.01 36 months 83.4% (n = 4 8 ) 34.9% (n = 10) < 0.01 81.1% (n = 33) 34.9% (n = 10) < 0.01 60 months 73.1% (n = 1 8 ) 25.5% (n = 3) < 0.01 66.2% (n = 12) 25.5% (n = 3) < 0.01 Disease-free survival 12 months 88.7% (n = 102) 61.2% (n = 14) < 0.01 86.3% (n = 7 0 ) 61.2% (n = 14) < 0.01 36 months 72.8% (n = 40) 24.6% (n = 5) < 0.01 67.1% (n = 26) 24.6% (n = 5) < 0.01 60 months 65.7% (n = 13) 14.8% (n = 2) < 0.01 56.8% (n = 8 ) 14.8% (n = 2) < 0.01 Statistics presented: p-values are calculated with log-rank tests with administrative censoring at predefined time points (12, 36, and 60 months) 1 3 468 Page 6 of 10 Journal of Robotic Surgery (2026) 20:468 RALS and prevents definitive conclusions about therapeu - tic benefit. Furthermore, the impact of adjuvant treatments could not be adequately evaluated because no control group was available. We cannot conclude that omitting or add - ing adjuvant EBRT and/or chemotherapy for patients who remained early stage FIGO I-II following RALS would lead to improved oncological outcomes. Adjuvant therapy strate- gies after RALS differ in national and international practice, comprehensive evaluation of oncological outcomes in a real-world tertiary care setting. Nonetheless, the retrospec - tive study design may limit the broader applicability of our results. A limitation is the heterogenous study population, resulting in small subgroup sizes that limit the ability to draw definite conclusions from our findings. The lack of a control group without comprehensive staging limits the interpret - ability of our findings to prognostic stratification following Fig. 2 Survival analysis 1 3 Page 7 of 10 468 Journal of Robotic Surgery (2026) 20:468 https://BioRender.com. Author contributions Alise de Jong, Cornelis G. Gerestein en Ronald P. Zweemer contributed to the study conception and design. Material preparation and data collection were performed by Jasper Markus and Alise de Jong. Analysis was performed by Alise de Jong. The first draft of the manuscript was written by Alise de Jong and all authors com - mented on previous versions of the manuscript. All authors read and approved the final manuscript. Funding No grants, sponsorships, or other sources of financial support were provided for performing this study and writing the manuscript. Data availability Metadata describing the participant data analyzed in this study are available through the HDSU catalogue ( h t t p s : / / c a t a l o g u e . h d s u . n l / H D S U / c o l l e c t i o n s / R o b E c O). Participant data was extracted from electronic medical patient files. Due to the sensitive and pro - tected nature of the underlying data, the raw datasets are not publicly available. Access to the data may be granted upon reasonable request, subject to approval of a research proposal and completion of a data- sharing agreement. Declarations Competing interests Ronald P. Zweemer is a proctor for robot-assist- ed surgery in gynaecological oncology on behalf of Intuitive Surgi - cal. The authors declare no further financial or non-financial conflicts of interest. Ethics approval The protocol was reviewed in accordance with insti - tutional guidelines and classified as exempt from Institutional Review Board approval. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. 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1. Oaknin A, Bosse TJ, Creutzberg CL, Giornelli G, Harter P, Joly F et al (2022) Endometrial cancer: ESMO clinical practice guide- line for diagnosis, treatment and follow-up. Ann Oncol 33:860– 877. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . a n n o n c . 2 0 2 2 . 0 5 . 0 0 9 2. Cancer Today (2022) [Internet]. World Health Organization. Available from: h t t p s : / / g c o . i a r c . f r / t o d a y / e n / d a t a v i z / t a b l e s ? m o d e = c a n c e r & g r o u p _ p o p u l a t i o n s = 1 & m u l t i p l e _ p o p u l a t i o n s = 1 3. Bray F, Laversanne M, Sung H, Ferlay J, Siegel RL, Soerjomata- ram I et al (2024) Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 74:229–263. h t t p s : / / d o i . o r g / 1 0 . 3 3 2 2 / c a a c . 2 1 8 3 4 which precludes definitive conclusions regarding the best optimal adjuvant treatment after RALS. In our cohort, the majority of patients who were not upstaged underwent VBT postoperatively. For patients who were upstaged, combined chemotherapy and radiotherapy were not routinely admin - istered, which differs from practice in some centres world - wide. Changes in the adjuvant treatment standards during the inclusion period may also have influenced oncological outcomes and may limit the generalisability of these find - ings to current treatment strategies. Another limitation concerns the variability in staging approaches, as the SLN procedure has already been implemented in several centres worldwide. Nevertheless, these differences are unlikely to have substantially influenced the observed upstaging rates. Future research should focus on integrating the clinico - pathological factors with molecular risk groups to inform the extent of surgical staging and to optimize adjuvant ther- apy strategies. The role of molecular risk stratification in informing surgical staging decisions, through evaluation of metastatic patterns across molecular subgroups, is currently being investigated in the prospective EUGENIE trial. A less invasive approach using SLN mapping may be considered for patients with EC at a high-intermediate- or high-risk for recurrence. Evaluating the clinical integration of molecular classification may allow for patient-specific adjuvant ther - apy decisions, ultimately contributing to improved survival outcomes.

This cohort study contributes to a better understanding of prognosis in patients with clinically early-stage EC at high- intermediate or high-risk for recurrence, who underwent surgically staging with RALS. We found that 5-year DSS for upstaged patients was 25.5% compared to 73.1% for patients who were not upstaged. RALS provides impor - tant prognostic information, while its therapeutic benefit warrants further investigation. Prospective research should assess the impact of adjuvant treatment strategies guided by surgical staging. Identifying patient subgroups using molecular risk classification, including patients with POL - Emut EEC and a favourable prognosis, for whom RALS or adjuvant therapy may offer none or little benefit, or patients with aggressive p53abn EC who should possibly receive adjuvant treatment regardless of surgical staging outcomes, could help redefine treatment protocols. Supplementary Information The online version contains supplementary material available at h t t p s : / / d o i . o r g / 1 0 . 1 0 0 7 / s 1 1 7 0 1 - 0 2 6 - 0 3 3 1 6 - 6.

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Gynecol Oncol 170:273–281. h t t p s : / / d o i . o r g / 1 0 . 1 0 1 6 / j . y g y n o . 2 0 2 3 . 0 1 . 0 2 2 1 3 Page 9 of 10 468 Journal of Robotic Surgery (2026) 20:468 Publisher’s Note Springer Nature remains neutral with regard to juris- dictional claims in published maps and institutional affiliations. intermediate- and high-risk endometrial cancer by sentinel lymph node biopsy implementation. Front Oncol 11:654285. h t t p s : / / d o i . o r g / 1 0 . 3 3 8 9 / f o n c . 2 0 2 1 . 6 5 4 2 8 5 1 3 468 Page 10 of 10