{"paper_id":"67108054-8ea9-49c2-8334-e30a49fad184","body_text":"Comprehensive genomic profiling (CGP) tests broadly explore treatments based on individual genomic information [ 1 ]. Until June 2023, three CGP tests have been clinically applicable in Japan, including a tumor-only panel, the FoundationOne ®  CDx (F1CDx) assay; a liquid biopsy panel, the FoundationOne Liquid ®  CDx assay; and a tumor/normal paired panel, the OncoGuide TM  NCC Oncopanel System [ 2 , 3 ]. All genomic profiling data and clinical information are transferred to the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) with written informed consent (agreement ratio, 99.7%), and the data are available for research use [ 3 ]. As the CGP tests under the universal health insurance system in Japan are only applicable to patients who have (already or almost) finished standardized treatments, the dataset is composed of patients with a poor prognosis for all cancer types. Liquid biopsy is limited to patients whose tissue specimens are not available or not suitable for CGP, and to date, F1CDx has been broadly tested (>75%) in Japan. The C-CAT database enables us to understand the mutational landscape, tumor mutational burden (TMB), and microsatellite instability (MSI) status of any type of advanced solid tumor [ 3 ].\nEndometrial, cervical, and ovarian cancers are the major types of gynecological malignancies. Platinum-based chemotherapy is typically used for these three cancers, and CGP tests are anticipated to identify novel treatment options. In endometrial cancer, genomic alterations are common in the phosphatidylinositol-3 kinase (PI3K) pathway (such as  PTEN ,  PIK3CA , and  PIK3R1 ) and the receptor tyrosine kinase/RAS pathway [ 4 , 5 ]. Notably, four major molecular subtypes have been identified: (i)  POLE  ultramutated (in the exonuclease domain), (ii) MSI-high (hypermutated), (iii) copy number low (mainly endometrioid), and (iv) copy number-high (serous-like) [ 4 , 6 ]. Immunohistochemistry for mismatch repair (MMR) genes and TP53 can alternatively be considered MSI-high (MSI-H) and copy number-high, respectively [ 7 ]. In cervical cancer, genomic alterations in  PIK3CA  are the most common (26%), followed by  EP300  (11%) and  FBXW7  (11%) [ 8 ]. Genomic alterations in  BRCA1 / 2  (both germline and somatic) and  TP53  are common in high-grade serous ovarian carcinomas [ 9 , 10 ]. Genomic alterations of  ARID1A  and  PIK3CA  have been detected in 30–60% of endometriosis-associated ovarian carcinomas, that is, endometrioid and clear cell ovarian carcinomas [ 11 ]. Genomic alterations in  KRAS  and  BRAF  in the MAPK pathway and  TP53  are common in mucinous ovarian carcinomas [ 12 ].\nBoth MSI-high and TMB-high (TMB-H, ≥10 mutations/megabase [mut/Mb]) are used as companion diagnostics for an immune checkpoint inhibitor (ICI), pembrolizumab, in solid tumors [ 13 , 14 ]. In addition to these tumor-agnostic indications, since December 2022, cemiplimab monotherapy (anti-programmed cell death 1 antibody) has been approved in recurrent cervical cancer as a second-line or later treatment in Japan, regardless of PD-L1 status [ 15 ]. Since December 2021, lenvatinib (a multi-tyrosine kinase inhibitor) plus pembrolizumab has been approved in Japan for the treatment of advanced/recurrent endometrial cancer, regardless of MSI status [ 16 ]. Recently, ICI plus platinum-based chemotherapy has shown significantly better overall survival and/or progression-free survival in both endometrial and cervical cancers (either primary advanced or recurrent) [ 17 , 18 , 19 ]. However, the prognostic benefits of ICI-containing regimens are significantly greater in the presence of MSI-H and/or deficient MMR (dMMR) in endometrial cancer and PD-L1 markers in cervical cancer [ 17 , 18 , 19 ]. In ovarian cancer, TMB-H or MSI-H remains the only indication for pembrolizumab, although several ongoing clinical trials include ICIs [ 20 ].\nIn the present study, we aimed to focus on the mutational landscape, TMB, and MSI status of endometrial, cervical, and ovarian cancers in Japanese patients using the C-CAT database of F1CDx (registered from June 2019 to May 2022;  https://www.ncc.go.jp/jp/c_cat/use/index.html , (accessed on 1 June 2022)).\n\nThis Japanese cohort study included 561 endometrial, 839 cervical, and 1606 ovarian cancers that were analyzed using F1CDx under health insurance coverage. The data were obtained from the C-CAT database organized by the National Cancer Center of Japan, which stores the CGP data tests [ 3 ]. The CGP tests in Japan are limited to patients with solid cancers who have finished (or are expected to finish) standard treatments for advanced unresectable diseases. Therefore, the patients enrolled generally had poor prognoses and were resistant to platinum-based chemotherapies for all three gynecological cancers. We logged into the C-CAT system to collect 3006 of 25,504 patients’ F1CDx data for the three gynecological cancers (between June 2019 and May 2022). We accessed the database on 1 June 2022. The workflow of this study is shown in  Figure 1 . The histological subtypes of each cancer are summarized in  Supplementary Table S1 . In this study, pure sarcomas were not included in endometrial cancer, whereas 2 sarcomas and 63 non-epithelial tumors were included in cervical and ovarian cancers, respectively. This study was approved by our institutional ethics committee (#2021341G) and the Information Utilization Review Board of C-CAT (#CDU2022-026N).\nF1CDx is a tumor-only panel using DNA isolated from formalin-fixed, paraffin-embedded tumor tissue specimens, which can detect substitutions, insertions, and deletions (indels); copy number alterations (CNAs) in 324 genes; gene rearrangements in 36 genes; and genomic signatures, including MSI and TMB [ 21 ]. MSI status is reported as “cannot be determined” when the quality is insufficient. TMB by F1CDx is determined by counting all synonymous and non-synonymous variants, except for hotspot genomic alterations, and is considered TMB-H when reported as ≥10 mut/Mb. In our study, all genetic variants, including single nucleotide variants, CNAs, and gene fusions, were annotated as pathogenic or likely pathogenic based on CIViC, BRCAExchange, ClinVar, and COSMIC [ 3 ]. MSI-H and TMB-H are tumor-agnostically approved as CDx for pembrolizumab in solid cancers in Japan. In this study, cases with “cannot be determined” for either TMB or MSI were excluded from the analysis (31 endometrial, 70 cervical, and 80 ovarian cancers).\nQuantitative variables were analyzed using one-way analysis of variance (ANOVA) (when normality was assumed) and the Kruskal–Wallis H test (when normality could not be assumed) for comparisons among the three groups. Pearson’s correlation test was used for correlation analysis between the two groups. All reported  p  values were two-tailed, and  p  < 0.05 was considered significant unless otherwise specified. All the graphs, calculations, and statistical analyses were performed using GraphPad Prism software 9.3.0 and R 4.2.0 software. The collation and visual analysis of alteration data were implemented using the “ComplexHeatmap” package in R.\n\nWe analyzed the genomic alterations (pathogenic or likely pathogenic) in F1CDx from the C-CAT database in 561 endometrial, 839 cervical, and 1606 ovarian cancer samples. The mutational landscape of frequently mutated (pathogenic or likely pathogenic) genes (top 30) in each cancer type and histological subtype is summarized in  Supplementary Figure S1 , and  Figure 2 , respectively (A: endometrial, B: cervical, and C: ovarian cancers).\nGenomic alterations were common in  TP53  ( n  = 305, 54.4%),  PIK3CA  ( n  = 231, 41.2%),  PTEN  ( n  = 194, 34.6%),  ARID1A  ( n  = 172, 30.7%), and  KRAS  ( n  = 146, 26.0%) ( Supplementary Figure S1A ). The ratio of  TP53  ( p  < 0.001) was significantly higher, and the ratios of  PTEN  ( p  < 0.001) and  PIK3CA  ( p  = 0.0028) were significantly lower in the C-CAT database compared with The Cancer Genome Atlas (TCGA) database. In addition, the ratio of pathogenic/likely pathogenic alterations in  POLE  in the exonuclease domain was only 1.4% (7.3% in the TCGA), supporting the favorable prognosis of  POLE- mutated endometrial carcinomas [ 4 ].\nEndometrioid endometrial carcinoma, accounting for 49.0% of our study, was characterized by genomic alterations of  PTEN  (47.6% vs. 13.7%,  p  < 0.001),  KRAS  (30.9% vs. 17.8%,  p  = 0.0037),  CTNNB1  (23.6% vs. 2.1%,  p  < 0.001), and  ARID1A  (37.8% vs. 22.6%,  p  = 0.0015), compared with non-endometrioid endometrial carcinomas (serous, clear cell, and mixed carcinomas) ( Figure 2 A). The high frequency of  PIK3CA  genomic alterations, regardless of the histological types, suggested the need for potential therapies targeting the PI3K pathway ( Figure 3 A and  Table 1 ).\nGenomic alterations of both  TP53  (80.8% vs. 35.3%,  p  < 0.001) and  ERBB2  (27.4% vs. 6.9%,  p  < 0.001) were more frequent in non-endometrioid carcinomas ( Figure 3 A).\nAmong the 839 samples, genomic alterations of  PIK3CA  were the most prevalent ( n  = 270, 32.2%), followed by  STK11  ( n  = 170, 20.3%),  TP53  ( n  = 166, 19.8%),  KRAS  ( n  = 117, 13.9%), and  CDKN2A  ( n  = 96, 11.4%) ( Supplementary Figure S1B ).  ERBB2  genomic alterations were observed at 9.7% (amplifications at 6.3% and pathogenic variants at 4.1%), which might lead to clinical trials ( Table 1 ). Squamous cell carcinomas ( n  = 389) exhibited a significantly higher  PIK3CA  mutation rate of 45.2% compared with 19.8% in non-squamous cell carcinomas ( n  = 420) ( Figure 3 B). In adenocarcinomas ( n  = 180),  KRAS  genomic alterations were most frequently observed (32.2%), followed by  TP53  (29.4%),  PIK3CA  (22.2%),  STK11  (22.2%),  CDKN2A  (18.3%),  ERBB2  (16.7%), and  ARID1A  (11.7%) ( Figure 2 B).\nAmong the 1606 samples,  TP53  genomic alterations ( n  = 1054, 65.6%) were the most frequent, followed by  ARID1A  ( n  = 407, 25.3%),  PIK3CA  ( n  = 406, 25.3%),  KRAS  ( n  = 272, 16.9%),  KMT2D  ( n  = 272, 16.9%), and  NOTCH3  ( n  = 270, 16.8%) ( Supplementary Figure S1C  and  Table 1 ).\nIn serous carcinomas, genomic alterations of  BRCA1  and  BRCA2  accounted for 21.2% (166/784) and 14.7% (115/784) of cases, respectively ( Figure 2 C). The coexistence rate of these two alterations was 4.8% (38/784), which was significantly higher than those reported by 0.6% (2/316) [ 12 ] and 0% (0/205) [ 30 ]. Genomic alterations in other homologous recombination repair genes included  ATM  (8.8%),  PALB2  (7.1%), and  CDK12  (6.6%) ( Figure 2 C). Genomic alterations in  TP53 ,  NF1, KRAS , and  PIK3CA  were detected in 90.4% ( n  = 709), 15.8% ( n  = 124), 11.9% ( n  = 93), and 11.7% ( n  = 92) of cases, respectively ( Figure 3 C).\nClear cell carcinomas were examined in 20.7% ( n  = 333) of the cases, with genomic alterations in  ARID1A  ( n  = 231, 69.4%) and  PIK3CA  ( n  = 190, 57.1%), consistent with previous reports [ 15 ] ( Figure 2 C). Genomic alterations of  TP53  were observed in 16.5% ( n  = 55) of the cases and were negatively associated with alterations in both  ARID1A  ( p  < 0.001) and  PIK3CA  ( p  < 0.001) ( Figure 2 C). Genomic alterations of  ERBB2  (primarily amplification) and  KRAS  were detected in 25% and 15% of the cases, respectively.\nIn endometrioid carcinomas, the ratios of genomic alterations in  TP53 ,  PIK3CA ,  KRAS ARID1A ,  PTEN,  and  CTNNB1  were 55.4%, 43.5%, 31.5%, 29.3%, 27.2%, and 19.6%, respectively.  TP53  alterations were negatively associated with alterations in  ARID1A  ( p  = 0.0006),  KRAS  ( p  = 0.0017),  PTEN  ( p  = 0.0002), and  CTNNB1 ( p  < 0.001).\nIn mucinous carcinomas, genomic alterations of  TP53 ,  KRAS ,  CDKN2A , and  CDKN2B  were detected in 61.5%, 59.3%, 44.0%, and 26.4% of the cases, respectively. Although genomic alterations of  BRAF  were approximately 20% [ 16 ], the ratio was only 5.5% ( n  = 5) in this study. Genomic alterations in  ERBB2  were detected in 16.5% of the cases.\nAmong the 561 endometrial cancer samples, 78 (13.9%) were TMB-H and 61 (10.9%) were MSI-H. A total of 58 of the 61 MSI-H tumors were TMB-H, whereas 20 of the 78 (25.6%) TMB-H tumors were non-MSI-H tumors ( Figure 4 A).\nAmong the 839 cervical cancer samples, 119 (14.2%) and 13 (1.5%) were TMB-H and MSI-H, respectively ( Figure 4 B). Only 1 of 13 (7.7%) cervical cancers with MSI-H was TMB-low (TMB-L) ( Figure 4 B). Among the 1606 ovarian cancer samples, 80 (5.0%) were MSI-H and 19 (1.2%) were TMB-H ( Figure 4 C). All 19 MSI-H ovarian cancer samples were classified as TMB-H ( Figure 4 C).\nThe TMB value in endometrial cancer was significantly higher than that in cervical cancer ( p  < 0.001 by one-way ANOVA with the Kruskal–Wallis test) and ovarian cancer ( p  < 0.001) ( Figure 4 D). The median TMB values in MSI-H tumors were 21.4 mut/Mb in endometrial, 23.0 mut/Mb in cervical, and 40.4 mut/Mb in ovarian cancers ( Figure 4 E), with a strong correlation between MSI and TMB in these three cancer types ( p  < 0.001) ( Figure 4 E).\nThe TMB and MSI statuses were distinct among the histological subtypes of each cancer ( Supplementary Table S2 ).\nIn endometrial cancer, the MSI-H ratio was significantly higher in endometrioid carcinomas (40/275, 14.5%) compared to serous carcinomas, clear cell carcinomas, and carcinosarcomas (5/215, 2.3%) ( p  < 0.001) ( Figure 5 A).\nIn cervical cancer, the MSI-H ratio was not significantly different between squamous cell carcinomas (1.3%) and adenocarcinomas (1.1%) ( Figure 5 A). In ovarian cancer, the MSI-H ratio was <4.0% in all histological subtypes and was significantly lower in serous carcinomas (2/784, 0.3%) compared with non-serous carcinomas (15/571, 2.6%) ( p  = 0.0002) ( Figure 5 A). In endometrial cancer, the ratio of TMB-H was high in adenosquamous carcinomas (5/17, 29.4%), mixed carcinomas (5/18, 27.8%), and endometrioid carcinomas (47/275, 17.1%), whereas it was only 4.9–7.7% in serous carcinomas, clear cell carcinomas, and carcinosarcomas ( Figure 5 B). In cervical cancer, the TMB-H ratio was significantly higher in squamous cell carcinomas (80/389, 20.6%) compared with adenocarcinomas (8.3%, 15/180) and mucinous carcinomas (5.0%, 4/80) ( p  = 0.0002 and  p  = 0.0004, respectively) ( Figure 5 B). In ovarian cancer, the TMB-H ratio was 3.3–6.5% in all histological subtypes.\nWe analyzed the correlation between genomic alterations in MMR genes (dMMR, defined as genomic alterations in  MLH1 ,  PMS2 ,  MSH2 , and  MSH6 ) and the MSI status. In endometrial cancer, the dMMR ratio was 31.1% (19/61) in MSI-H, which was significantly higher than the 2.8% (13/469) reported in microsatellite stable (MSS) tumors ( p  < 0.001) ( Supplementary Figure S2A ). The dMMR ratios in MSI-H and MSS in cervical cancer were 61.5% (8/13) and 4.6% (35/756) ( p  < 0.001), respectively, whereas those in ovarian cancer were 84.2% (16/19) and 13.5% (203/1507) ( p  < 0.001), respectively ( Supplementary Figure S2A ).\nNext, we analyzed the dMMR ratio in MSS tumors. The dMMR ratio was significantly higher in TMB-H tumors (25%) compared with TMB-L tumors (2.5%) in MSS endometrial cancer ( p  = 0.0003) ( Supplementary Figure S2B ). In MSS cervical cancer, dMMR was also more frequent in TMB-H (9.4%) compared with TMB-L (4.3%) ( p  = 0.0302). No statistically significant difference was detected in ovarian cancer (22.4% vs. 13.5%,  p  = 0.0769) ( Supplementary Figure S2B ).\nThe highest prevalence of genomic alterations in MSI-H endometrial cancer was observed in  MSH6  ( n  = 14, 23.0%), followed by  MSH2  ( n  = 8, 13.1%),  MLH1  ( n  = 4, 6.6%), and  PMS2  ( n  = 1, 1.6%) ( Supplementary Table S3 ). Similarly, this prevalence was confirmed in ovarian cancer with MSI-H, with genomic alteration rates of  MSH6 ,  MSH2 ,  MLH1 , and  PMS2  of 52.6%, 36.8%, 31.6%, and 10.5%, respectively. In MSI-H cervical cancer, the genomic alteration rates of  MSH6  and  MLH1  were the highest ( n  = 4, 30.8%) ( Supplementary Table S3 ).\nAll  POLE  variants (including variants of unknown significance [VUS]) are listed in  Table 2 .\nThe ultramutated genotype (TMB > 100 mut/Mb) was identified in eight tumors (five endometrial and three ovarian cancers). In endometrial cancer, all eight (1.4%)  POLE  exonuclease-mutated tumors were TMB-H (median TMB, 90.78 mut/Mb), of which only one was MSI-H ( Table 2 ). Three MSI-H and TMB-H tumors showed VUS of  POLE  outside the exonuclease domain, which should be categorized as MSI-H, not as a  POLE  subgroup ( Table 2 ). Pathogenic/likely pathogenic variants in the  POLE  exonuclease domain were detected in one case (0.12%) of cervical cancer and three cases (0.19%) of ovarian cancer. None of the  POLE  variants outside the exonuclease domain were annotated as pathogenic or likely pathogenic ( Table 2 ).\nFinally, we focused on the mutational landscape of “TMB-H with MSS” and “MSI-H” tumors in each cancer type. The most frequent genomic alteration in the “MSI-H” group was  ARID1A  in all three cancer types. The ratios were 96.7% (59/61) in endometrial, 76.9% (10/13) in cervical, and 89.5% (17/19) in ovarian cancers ( Supplementary Figure S3A–C ).  PTEN  was another MSI-H-related gene. The ratios of  PTEN  alterations in the “MSI-H” group were 85.2% (52/61) in endometrial, 69.2% (9/13) in cervical, and 57.9% (11/19) in ovarian cancers, whereas the ratios of  PTEN  alterations in the “MSS with TMB-L” group were 28.2% (127/451) in endometrial, 7.5% (49/650) in cervical, and 6.3% (92/1449) in ovarian cancers.\nIn “TMB-H with MSS” tumors, the ratio of genomic alterations in  PIK3CA  was the most or the second highest, which was 61.1% in endometrial, 51.4% in cervical, and 31.0% in ovarian cancers ( Supplementary Figure S3 ). Genomic alterations of  TP53  were most common in the TMB-H with MSS group in endometrial (61.1%) and ovarian (82.8%) cancers, whereas the rate was 12.0% in cervical cancer (usually human papillomavirus [HPV], which relates to the impairment of TP53 by the ubiquitin–proteasome pathway). The ratio of genomic alterations in  CDKN2A  and  CDKN2B  was also high in endometrial and ovarian cancers ( Supplementary Figure S3 ).\n\nIn this study, we analyzed 3006 endometrial, cervical, and ovarian cancers using a tumor-only panel, F1CDx. The Japanese CGP test dataset is unique in terms of eligible patients and insurance coverage. All the patients have finished or are expected to finish the standardized treatments and take the CGP tests under universal health insurance coverage [ 3 , 31 ]. Thus, any poor prognosis in Japanese patients with cancer may allow them to undergo CGP tests. Furthermore, a sufficient number of tumor specimens are usually available through surgery and/or biopsy. Therefore, the C-CAT database is suitable for analyzing the genomic profiles of patients with gynecological cancer with a poor prognosis.\nIn endometrial cancer, a comparison with the TCGA database highlighted the high incidence of genomic alterations of  TP53  (54.4%) and the low incidence of genomic alterations of  POLE  (1.4%) in this database. This discrepancy supports the significance of the molecular classification of “Proactive Molecular Risk Classifier for Endometrial Cancer” in endometrial cancer by POLE, dMMR, and TP53 [ 32 ]. Drug development is highly warranted in genomic alterations of the PI3K ( PTEN  and  PIK3CA ), RAS ( KRAS ), and wnt/β-catenin ( CTNNB1 ) pathways in endometrioid carcinomas and  TP53 ,  ERBB2 , and  PIK3CA  in non-endometrioid carcinomas ( Table 1 ). A WEE1 inhibitor, adavosertib, showed an objective response rate of 29.4% in recurrent uterine serous carcinomas (usually  TP53  mutated), and an international phase IIb study is ongoing [ 33 , 34 ]. Further development of precision medicine in endometrial cancer is warranted.\nIn cervical cancer, the C-CAT dataset was helpful for elucidating the genomic profiling of adenocarcinomas, as the ratio of non-squamous cell carcinomas was significantly lower in the TCGA dataset (19.1%) than in the C-CAT database (53.6%) [ 8 ]. Key molecular targets, especially in adenocarcinomas, include  KRAS ,  ERBB2 , and  ARID1A.  According to the recently published 5th edition of the World Health Organization classification, cervical cancer is classified as HPV-associated and HPV-independent for each histological type [ 35 ]. As both the TP53 and RB pathways are impaired by HPV-E6 and HPV-E7 oncoproteins, respectively, genomic alterations of  TP53 ,  RB , and  CDKN2A / 2B  are informative for speculating HPV-independent cervical cancers, especially in gastric-type mucinous adenocarcinomas [ 36 , 37 ].\nOne limitation of the C-CAT database is that data on low-grade serous ovarian carcinomas are mixed with those on high-grade serous carcinomas. Genomic alterations of  TP53  in 90% of serous carcinomas suggest that these tumors represent high-grade serous carcinomas. The RAS-MAPK signaling pathway (genomic alterations of  NF1  at 16% and  KRAS  at 12% with mutual exclusivity), the PI3K-mTOR pathway ( PIK3CA  at 12% and  TSC2  at 8%), and certain receptor tyrosine kinases ( ROS1  at 9% and  ERBB2  at 8%) might be candidates for targeted therapy in serous carcinomas. The pathogenicity of each alteration, especially in  BRCA1  and  BRCA2 , should be carefully addressed [ 9 , 30 ]. Drug development targeting  ARID1A  and  PIK3CA  in clear-cell ovarian carcinomas is also warranted. Currently, a p110alpha selective inhibitor, CYH33, is under phase 2 clinical trials ( NCT05043922 , jRCT2031210216), which recruits patients with clear cell ovarian carcinoma with hotspot mutations in  PIK3CA  ( Table 1 ) [ 29 ]. Targeting the RAS-MAPK pathway should be key in mucinous carcinomas.\nCandidate tumor-agnostic molecular targets in the three gynecological malignancies included  ERBB2 ,  PIK3CA ,  ARID1A , and  KRAS . An antibody-drug conjugate, trastuzumab deruxtecan, showed an overall response rate of 54.5–70.0% in endometrial carcinosarcomas positive for HER2 in the STATICE trial [ 28 ]. Genomic alterations in  ARID1A  may lead to novel molecular-targeted therapies, including an EZH2 inhibitor and an enzyme for antioxidant glutathione synthesis ( Table 1 ) [ 23 , 24 ]. p110alpha selective inhibitors (alpelisib), KRAS G12C  inhibitors (sotorasib), KRAS G12D  degraders (ASP3082), and a CBP/β-catenin inhibitor (E7386) may be candidates [ 22 , 25 , 26 , 27 ]. The Japanese Gynecologic Oncology Group is currently conducting a basket trial on niraparib monotherapy for any gynecological cancer (except ovarian cancer) with  BRCA1 / 2  genomic alterations, which targets a rare fraction of each cancer type [ 38 ].\nIn agreement with previous findings, MSI-H in this study was the main causative genomic finding for TMB-H induction in endometrial cancer, whereas it shared only 10% and 24% of TMB-H in cervical and ovarian cancers, respectively [ 39 , 40 ]. A low TMB-H ratio (5.0%) in ovarian cancer may be associated with limited sensitivity to ICIs [ 41 ]. A comparison between “TMB-H with MSS” and “MSI-H” in each cancer type is informative to elucidate real “driver” alterations. In endometrial and ovarian cancers, the frequency of genomic alterations in  TP53  and  CDKN2A / 2B  was significantly higher in the group of “TMB-H with MSS”. These findings suggest that TMB-H should be subclassified according to the MSI status. Although pembrolizumab has been approved in any solid cancers with either TMB-H and MSI-H, combination therapies with immune checkpoint inhibitors may be developed separately according to the status of TMB and MSI.\nThis study has some limitations. First, CGP tests in Japan are reimbursed only for patients who have (almost) finished standardized treatments, suggesting that patients with rapid progression may miss the opportunity to undergo CGP tests. In addition, this study lacks data from patients without medical insurance due to the universal health insurance system in Japan. Second, the response to genome-matched therapies was not analyzed in this study because of the low accessibility of the recommended drugs. Third, the C-CAT database was deposited at designated hospitals located in Japan. Therefore, most of the patients were Japanese.\n\nThis study uniquely illustrates the genomic landscape of three major gynecological cancers in the Japanese cohort. It highlights the necessity of future drug developments in each cancer type and each histological subtype.  ERBB2 ,  PIK3CA ,  ARID1A , and  KRAS  would be key molecular targets in gynecological cancers. Furthermore, the prevalence and correlation between TMB and MSI may influence future immunotherapy, including combination therapies. These insights reinforce the necessity of molecular classification in understanding tumor biology and developing personalized therapies, underlining the potential of genomic profiling in precision oncology.","source_license":"CC-BY-4.0","license_restricted":false}