Britta Weigelt

Interferon response and epigenetic modulation by SMARCA4 mutations drive ovarian tumor immunogenicity

Cell-intrinsic mechanisms of immunogenicity in ovarian cancer (OC) are not well understood. Damaging mutations in the SWI/SNF chromatin remodeling complex, such as SMARCA4 (BRG1), are associated with improved response to immune checkpoint blockade; however, the mechanism by which this occurs is unclear. We found that SMARCA4 loss in OC models resulted in increased cancer cell–intrinsic immunogenicity, characterized by up-regulation of long-terminal RNA repeats, increased expression of interferon-stimulated genes, and up-regulation of antigen presentation machinery. Notably, this response was dependent on STING, MAVS, and IRF3 signaling but was independent of the type I interferon receptor. Mouse ovarian and melanoma tumors with SMARCA4 loss demonstrated increased infiltration and activation of cytotoxic T cells, NK cells, and myeloid cells in the tumor microenvironment. These results were recapitulated in BRG1 inhibitor–treated SMARCA4- proficient tumor models, suggesting that modulation of chromatin remodeling through targeting SMARCA4 may serve as a strategy to overcome cancer immune evasion.

Clinicopathologic Features, Molecular Landscape, and Prognostic Implications of Ovarian Low-grade Serous Tumors with Histologic Transformation

Abstract Purpose: The purpose of this study was to characterize the clinicopathologic features, molecular genetic landscape, and clinical behavior of ovarian low-grade serous tumors with histologic transformation (LGS-HT) to indeterminate/high-grade carcinoma. Experimental Design: LGS-HT were retrospectively identified from an institutional cohort of patients with ovarian cancer and underwent central pathology re-review. Data on clinicopathologic characteristics, including age, stage, surgical outcomes, systemic treatments, and overall survival (OS), were collected. IHC profiling and next-generation sequencing were performed. OS comparisons were performed with our institutional cohorts of ovarian low-grade serous carcinoma (n = 109) and high-grade serous carcinoma (n = 1,672). Results: From 4,371 ovarian serous cancers, 40 (0.9%) LGS-HT were identified: 30 with synchronous low-grade and higher-grade tumor components at initial diagnosis and 10 with an ovarian low-grade serous neoplasm that recurred as a higher-grade carcinoma. The most common somatic driver mutations included TP53 (38.5%), KRAS (21.8%), NF1 (15.6%), BRAF (15.6%), and NRAS (12.5%), with coexisting TP53 and RAS/RAF mutations in 18.8% of cases. Alterations in DNA damage response genes (BRCA2, PALB2, CHEK2, ATM, NBN, and RECQL4) were identified in LGS-HT lacking TP53 genetic alterations. Synchronous low-grade and higher-grade tumor components at initial diagnosis were associated with poorer OS (median, 59.7 months) compared with low-grade serous carcinoma (median, 105.4 months; P = 0.026) and were similar to high-grade serous carcinoma (median, 48.8 months; P = 0.61). Severe nuclear atypia and the absence of RAS/RAF-driver mutations were significant adverse prognostic factors. Conclusions: LGS-HT exhibit both low-grade and high-grade morphologic and molecular features, representing an exception to the dualistic classification of ovarian serous neoplasms. The presence of a definitive high-grade carcinoma component in a low-grade serous tumor portends aggressive clinical behavior.

A tale of two pathways: Review of immune checkpoint inhibitors in DNA mismatch repair‐deficient and microsatellite instability‐high endometrial cancers

AbstractThe DNA mismatch repair (MMR) pathway is critical for correcting DNA mismatches generated during DNA replication. MMR‐deficiency (MMR‐D) leads to microsatellite instability (MSI) associated with an increased mutation rate, driving cancer development. This is particularly relevant in endometrial cancer (EC) as 25%–30% of tumors are of MMR‐D/MSI‐high (MSI‐H) phenotype. Comprehensive assessment using immunohistochemistry (IHC) and sequencing‐based techniques are necessary to fully evaluate ECs given the importance of molecular subtyping in staging and prognosis. This also influences treatment selection as clinical trials have demonstrated survival benefits for immune checkpoint inhibitors (ICIs) alone and in combination with chemotherapy for MMR‐D/MSI‐H EC patients in various treatment settings. As a portion of MMR‐D/MSI‐H ECs are driven by Lynch syndrome, an inherited cancer predisposition syndrome that is also associated with colorectal cancer, this molecular subtype also prompts germline assessment that can affect at‐risk family members. Additionally, heterogeneity in the tumor immune microenvironment and tumor mutation burden (TMB) have been described by MMR mechanism, meaning MLH1 promoter hypermethylation versus germline/somatic MMR gene mutation, and this may affect response to ICI therapies. Variations by ancestry in prevalence and mechanism of MMR‐D/MSI‐H tumors have also been reported and may influence health disparities given observed differences in tumors of Black compared to White patients which may affect ICI eligibility. These observations highlight the need for additional prospective studies to evaluate the nuances regarding MMR‐D heterogeneity as well as markers of resistance to inform future trials of combination therapies to further improve outcomes for patients with EC.

Moving into the modern era of molecular classification for endometrial cancer

AbstractThe molecular subtypes of endometrial carcinoma (EC) were first described by The Cancer Genome Atlas (TCGA) a decade ago. Using surrogate approaches, the molecular classification has been demonstrated to be prognostic across EC patients and to have predictive implications. Starting in 2020, the molecular classification has been incorporated into multiple guidelines as part of the risk assessment and most recently into the International Federation of Gynecology and Obstetrics (FIGO) staging. This review article discusses the implementation of the EC molecular classification into clinical practice, the therapeutic implications, and the molecular and clinical heterogeneity of the EC molecular subtypes.

Decreased HER2 expression in endometrial cancer following anti‐HER2 therapy

Abstract Trastuzumab has demonstrated clinical efficacy in the treatment of HER2‐positive serous endometrial cancer (EC), which led to its incorporation into standard‐of‐care management of this aggressive disease. Acquired resistance remains an important challenge, however, and its underlying mechanisms in EC are unknown. To define the molecular changes that occur in response to anti‐HER2 therapy in EC, targeted next‐generation sequencing (NGS), HER2 immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) were performed on pre‐ and post‐treatment tumour samples from 14 patients with EC treated with trastuzumab or trastuzumab emtansine. Recurrent tumours after anti‐HER2 therapy acquired additional genetic alterations compared with matched pre‐treatment ECs and frequently showed decreased HER2 protein expression by IHC (7/14, 50%). Complete/near‐complete absence of HER2 protein expression (score 0/1+) observed post‐treatment (4/14, 29%) was associated with retained HER2 gene amplification ( n  = 3) or copy number neutral status ( n  = 1). Whole‐exome sequencing performed on primary and recurrent tumours from the latter case, which exhibited genetic heterogeneity of HER2 amplification in the primary tumour, revealed selection of an early HER2 ‐non‐amplified clone following therapy. Our findings demonstrate that loss of target expression, by selection of HER2 ‐non‐amplified clones or, more commonly, by downregulation of expression, may constitute a mechanism of resistance to anti‐HER2 therapy in HER2‐positive EC. © 2023 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Pathogenic germline variants in patients with endometrial cancer of diverse ancestry

AbstractBackgroundRacial disparities in outcomes exist in endometrial cancer (EC). The contribution of ancestry‐based variations in germline pathogenic variants (gPVs) is unknown.MethodsGermline assessment of ≥76 cancer predisposition genes was performed in patients with EC undergoing tumor‐normal Memorial Sloan Kettering Cancer Center Integrated Mutation Profiling of Actionable Cancer Targets sequencing from January 1, 2015 through June 30, 2021. Self‐reported race/ethnicity and Ashkenazi Jewish ancestry data classified patients into groups. Genetic ancestry was inferred from Memorial Sloan Kettering Cancer Center Integrated Mutation Profiling of Actionable Cancer Targets. Rates of gPV and genetic counseling were compared by ancestry.ResultsAmong 1625 patients with EC, 216 (13%) had gPVs; 15 had >1 gPV. Rates of gPV varied by self‐reported ancestry (Ashkenazi Jewish, 40/202 [20%]; Asian, 15/124 [12%]; Black/African American (AA), 12/171 [7.0%]; Hispanic, 15/124 [12%]; non‐Hispanic (NH) White, 129/927 [14%]; missing, 5/77 [6.5%]; p = .009], with similar findings by genetic ancestry (p < .001). We observed a lower likelihood of gPVs in patients of Black/AA (odds ratio [OR], 0.44; 95% CI, 0.22–0.81) and African (AFR) ancestry (OR, 0.42; 95% CI, 0.18–0.85) and a higher likelihood in patients of Ashkenazi Jewish genetic ancestry (OR, 1.62; 95% CI; 1.11–2.34) compared with patients of non‐Hispanic White/European ancestry, even after adjustment for age and molecular subtype. Somatic landscape influenced gPVs with lower rates of microsatellite instability‐high tumors in patients of Black/AA and AFR ancestry. Among those with newly identified gPVs (n = 114), 102 (89%) were seen for genetic counseling, with lowest rates among Black/AA (75%) and AFR patients (67%).ConclusionsIn those with EC, gPV and genetic counseling varied by ancestry, with lowest rates among Black/AA and AFR patients, potentially contributing to disparities in outcomes given implications for treatment and cancer prevention.Plain Language Summary Black women with endometrial cancer do worse than White women, and there are many reasons for this disparity. Certain genetic changes from birth (mutations) can increase the risk of cancer, and it is unknown if rates of these changes are different between different ancestry groups. Genetic mutations in 1625 diverse women with endometrial cancer were studied and the lowest rates of mutations and genetic counseling were found in Black and African ancestry women. This could affect their treatment options as well as their families and may make disparities worse.

ERBB2 amplification is a late event in the pathogenesis of high‐grade endometrial carcinomas with heterogeneous HER2 expression

Abstract Intratumor heterogeneity of ERBB2 amplification/HER2 overexpression is frequently observed in ERBB2 ‐amplified high‐grade endometrial carcinoma (HG‐EC) and contributes to anti‐HER2 therapy resistance. To elucidate the molecular pathogenesis and evolutionary trajectory of HER2‐heterogeneous HG‐ECs, we performed next‐generation sequencing of spatially distinct HER2‐negative (HER2−) and HER2‐positive (HER2+) tumor areas from nine tumors (whole exome, n  = 7; targeted panel, n  = 2). HER2− and HER2+ components shared a high proportion of somatic mutations, particularly clonal mutations, including known EC driver genetic alterations. The 17q12 amplicon, containing the ERBB2 gene, was the only significant recurrent copy number alteration that differed between HER2− and HER2+ components. By unsupervised hierarchical clustering of genome‐wide copy number alterations, samples clustered together at the patient level rather than by HER2 status. Intra‐ and intertumor heterogeneity in ERBB2 amplification/HER2 expression was also observed in metastatic lesions, which likely originated from different tumor subpopulations within the primary tumor. Exploratory spatial transcriptomics analyses revealed gene expression differences associated with HER2 status, including a shift from ‘mesenchymal‐like’ toward epithelial differentiation in HER2+ components for a subset of cases, a finding that warrants further investigation. Our results suggest that HER2 heterogeneity in HG‐EC reflects late acquisition of ERBB2 amplification during tumor evolution. ERBB2 does not appear to drive tumor initiation in HER2‐heterogeneous HG‐EC but likely serves a context‐dependent role in the progression of established tumors. © 2026 The Pathological Society of Great Britain and Ireland.

A Subset of Serous Tubal Intraepithelial Carcinoma (STIC)–Like Lesions and Concurrent High-Grade Endometrial Carcinoma Are Genomically Related Entities

In patients with high-grade endometrial carcinoma (HG-EC), concurrent isolated serous tubal intraepithelial carcinoma (STIC) or STIC-like lesions (STIC-LLs) in the fallopian tube(s) may be found. We sought to determine whether concurrently diagnosed HG-ECs and STIC-LLs are genetically related. Six HG-ECs, including serous carcinomas (n = 4) and carcinosarcomas with serous epithelial component (n = 2), with cooccurring STIC-LLs were identified and subjected to microdissection, DNA extraction, and panel sequencing targeting 468 cancer-related genes or, if DNA quantities were limited, to Sanger sequencing. WT1 and p53 protein expression was assessed by immunohistochemistry. We found that 3 HG-ECs and concurrent STIC-LLs shared pathogenic mutations, such as TP53 hotspot, NF2, FBXW7, and PIK3CA mutations. Immunohistochemical analysis revealed that the HG-EC of case 5 lacked WT1 expression and had aberrant p53 expression, although the matched STIC-LL displayed diffuse WT1 expression. Of the remaining 3 cases that did not show evidence of genetic relatedness based on the targeted sequencing panel, 1 STIC-LL harbored a clonal TP53 missense mutation, whereas the matched HG-EC had a distinct clonal TP53 hotspot mutation, a clonal FBXW7 hotspot mutation, and ERBB2 amplification. At the protein level, the p53 expression patterns of the HG-ECs and STIC-LLs were concordant in these 3 cases. Here, we demonstrate that cooccurring HG-ECs and STIC-LLs are genetically related in a subset of cases.

Evolution and Co-occurrence of PI3K Pathway Gene Mutations in Endometrial Carcinoma Molecular Subtypes at the Single-Cell Level

Abstract Purpose: The PI3K pathway is altered in >85% of endometrioid endometrial carcinomas (EEC), with multiple mutations commonly co-occurring. Yet, the therapeutic effects of single-agent PI3K pathway inhibitors have been limited. We used single-cell sequencing to determine whether co-occurring PTEN, PIK3CA, and/or PIK3R1 somatic mutations in EECs stratified by molecular subtype originated through convergent or linear evolution. Experimental Design: Banked frozen EECs with co-occurring PI3K pathway mutations of no specific molecular profile (NSMP; n = 5), mismatch repair–deficient (MMRd; n = 3), and POLE (n = 3) subtypes were selected for single-nucleus DNA sequencing targeting hotspot variants of 64 cancer-related genes and the PTEN, PIK3R1, and PIK3CA coding sequences. EEC cell lines and nonmalignant samples were used to define error rates and filter false-positive calls. Results: Single-nucleus analyses (n = 50,009 cells) revealed that in NSMP EECs, the co-occurring PIK3CA, PIK3R1, and/or PTEN mutations affected nearly all cells through linear evolution. MMRd EECs displayed higher levels of genetic heterogeneity, harboring PI3K pathway gene mutations in subsets of cells ranging from 3.9% to 96%. POLE EECs had the highest level of clonal diversity and harbored multiple, minor subclonal structures in all cases, through convergent evolution. We found a clear distinction between nearly clonal PI3K pathway gene alterations (>95%) and multiple, minor mutually exclusive subclones only affecting 1.4% to 27% of the tumor cells sequenced. Conclusions: Our exploratory, hypothesis-generating analysis suggests that PI3K pathway alterations evolve distinctly in MMRd/POLE compared with NSMP EECs, which may have therapeutic consequences. Further studies on the signaling output and PI3K pathway inhibitor response in EECs with subclonal PI3K pathway alterations are warranted.

Molecular Characterization of Endometrial Carcinomas in Black and White Patients Reveals Disparate Drivers with Therapeutic Implications

Abstract Although the incidence of endometrial carcinoma (EC) is similar in Black and White women, racial disparities are stark, with the highest mortality rates observed among Black patients. Here, analysis of 1,882 prospectively sequenced ECs using a clinical FDA-authorized tumor–normal panel revealed a significantly higher prevalence of high-risk histologic and molecular EC subtypes in self-identified Black (n = 259) compared with White (n = 1,623) patients. Clinically actionable alterations, including high tumor mutational burden/microsatellite instability, which confer benefit from immunotherapy, were less frequent in ECs from Black than from White patients. Ultramutated POLE molecular subtype ECs associated with favorable outcomes were rare in Black patients. Results were confirmed by genetic ancestry analysis. CCNE1 gene amplification, which is associated with aggressive clinical behavior, was more prevalent in carcinosarcomas occurring in Black than in White patients. ECs from Black and White patients display important differences in their histologic types, molecular subtypes, driver genetic alterations, and therapeutic targets. Significance: Our comprehensive analysis of prospectively clinically sequenced ECs revealed significant differences in their histologic and molecular composition and in the presence of therapeutic targets in Black versus White patients. These findings emphasize the importance of incorporating diverse populations into molecular studies and clinical trials to address EC disparities. This article is featured in Selected Articles from This Issue, p. 2293

A Phase II Study of Fulvestrant plus Abemaciclib in Hormone Receptor–Positive Advanced or Recurrent Endometrial Cancer

Abstract Purpose: Inhibition of the cyclin D–cyclin-dependent kinase (CDK)4/6–INK4–retinoblastoma pathway can overcome acquired or de novo treatment resistance to endocrine monotherapy. Responses to endocrine monotherapy in advanced endometrial cancer are suboptimal, perhaps due to genomic alterations that promote estrogen receptor–independent cyclin D1–CDK4/6 activation. We hypothesized that the addition of abemaciclib, a CDK4/6 kinase inhibitor, to antiestrogen therapy with fulvestrant would be an effective therapeutic strategy in patients with advanced or recurrent endometrial cancer. Patients and Methods: In this phase II study, patients with advanced or recurrent endometrial cancer received 150 mg of abemaciclib orally twice daily with 500 mg of fulvestrant intramuscularly monthly with a 2-week loading dose. Eligibility included estrogen receptor or progesterone receptor expression ≥1% by IHC, measurable disease, ≤2 prior lines of chemotherapy, and ≤1 prior lines of hormonal therapy. The primary endpoint was the objective response rate by RECIST v1.1. Results: Twenty-seven patients initiated therapy, and 25 were evaluable for efficacy. Eleven patients achieved partial response; 10 responses (91%) were in copy number–low/no specific molecular profile tumors, 1 response (9%) was in a microsatellite instability–high tumor, and no responses were observed in copy number–high/TP53abnormal tumors. The objective response rate was 44% (90% confidence interval, 27.0%–62.1%). The median duration of response was 15.6 months. The median progression-free survival was 9.0 months (90% confidence interval, 1.8–20.4). The most common grade ≥3 treatment-related adverse events were neutropenia (26%) and anemia (19%); no new safety signals were identified. Conclusions: The combination of abemaciclib and fulvestrant has promising activity with durable responses in advanced or recurrent endometrial cancer; a randomized trial is planned. See related commentary by Garg and Oza, p. 2073

ERBB2 mutations define a subgroup of endometrial carcinomas associated with high tumor mutational burden and the microsatellite instability‐high (MSI‐H) molecular subtype

Anti‐HER2 therapy is indicated for erb‐b2 receptor tyrosine kinase 2 ( ERBB2 )‐amplified/overexpressing endometrial carcinoma (EC). Mutations constitute another mode of ERBB2 activation, but only rare ERBB2 ‐mutated ECs have been reported. We sought to characterize the clinicopathologic and genetic features of ERBB2 ‐mutated EC. From an institutional cohort of 2638 ECs subjected to clinical tumor‐normal panel sequencing, 69 (2.6%) with pathogenic ERBB2 mutation(s) were identified, of which 11 were also ERBB2 ‐amplified. The most frequent ERBB2 hotspot mutations were V842I (38%) and R678Q (25%). ERBB2 mutations were clonal in 87% of evaluable cases. Immunohistochemistry revealed low HER2 protein expression in most ERBB2 ‐mutated ECs (0/1+ in 66%, 2+ in 27%); all 3+ tumors (7.3%) were also ERBB2 ‐amplified. Compared to ERBB2 ‐wildtype ECs (with or without ERBB2 amplification), ERBB2 ‐mutated/non‐amplified ECs were enriched for the microsatellite instability‐high (MSI‐H) and, to a lesser extent, DNA polymerase epsilon, catalytic subunit ( POLE ) molecular subtypes, and associated with high tumor mutational burden and low chromosomal instability. Survival outcomes were similar between patients with ERBB2 ‐mutated/non‐amplified versus wildtype EC, whereas ERBB2 amplification was associated with worse prognosis on univariate, but not multivariate, analyses. In conclusion, ERBB2 mutation defines a rare subgroup of ECs that is pathogenically distinct from ERBB2 ‐wildtype and ERBB2 ‐amplified ECs.

Comprehensive analysis of germline drivers in endometrial cancer

AbstractBackgroundWe sought to determine the prevalence of germline pathogenic variants (gPVs) in unselected patients with endometrial cancer (EC), define biallelic gPVs within tumors, and describe their associations with clinicopathologic features.MethodsGermline assessment of at least 76 cancer predisposition genes was performed in patients with EC undergoing clinical tumor-normal Memorial Sloan Kettering–Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) sequencing from January 1, 2015, to June 30, 2021. In patients with gPVs, biallelic alterations in ECs were identified through analysis of loss of heterozygosity and somatic PVs. Clinicopathologic variables were compared using nonparametric tests.ResultsOf 1625 patients with EC, 216 (13%) had gPVs, and 15 patients had 2 gPVs. There were 231 gPVs in 35 genes (75 [32%] high penetrance; 39 [17%] moderate penetrance; and 117 [51%] low, recessive, or uncertain penetrance). Compared with those without gPVs, patients with gPVs were younger (P = .002), more often White (P = .009), and less obese (P = .025) and had differences in distribution of tumor histology (P = .017) and molecular subtype (P < .001). Among 231 gPVs, 74 (32%) exhibited biallelic inactivation within tumors. For high-penetrance gPVs, 63% (47 of 75) of ECs had biallelic alterations, primarily affecting mismatch repair (MMR) and homologous recombination related genes, including BRCA1,BRCA2, RAD51D, and PALB2. Biallelic inactivation varied across molecular subtypes with highest rates in microsatellite instability-high (MSI-H) or copy-number (CN)–high subtypes (3 of 12 [25%] POLE, 30 of 77 [39%] MSI-H, 27 of 60 [45%] CN-high, 9 of 57 [16%] CN-low; P < .001).ConclusionsOf unselected patients with EC, 13% had gPVs, with 63% of gPVs in high-penetrance genes (MMR and homologous recombination) exhibiting biallelic inactivation, potentially driving cancer development. This supports germline assessment in EC given implications for treatment and cancer prevention.

Risk Stratification of Stage I Grade 3 Endometrioid Endometrial Carcinoma in the Era of Molecular Classification

PURPOSE The role of adjuvant therapy in stage I grade 3 endometrioid endometrial carcinoma (EEC) is debatable. We sought to define the agreement between Post Operative Radiation Therapy in Endometrial Carcinoma 1 (PORTEC-1) high-intermediate risk (HIR) and Gynecologic Oncology Group (GOG)-99 HIR criteria, assess their concordance with The Cancer Genome Atlas molecular subtypes, and evaluate oncologic outcomes in this population. METHODS We identified patients with stage I grade 3 EECs who underwent surgical staging at our institution from January 2014 to January 2020. Patients were stratified into PORTEC-1 HIR, GOG-99 HIR, and The Cancer Genome Atlas molecular subtypes. Adjuvant treatment, and progression-free survival (PFS), and overall survival (OS) were analyzed. RESULTS Seventy-five patients were included. The agreement between PORTEC-1 and GOG-99 HIR classification was 68% (95% CI, 56.2 to 78.3), with a kappa of 0.36 ( P = .001). There was no agreement between PORTEC-1 or GOG-99 HIR classification and a dichotomized molecular classification (copy number-high [CN-H] v other subtypes), with a kappa of 0.03 ( P = .39) and −0.03 ( P = .601), respectively. There was no difference in PFS between PORTEC-1 HIR and non-HIR (HR, 10.9; 95% CI, 0.28 to 4.21) or between GOG-99 HIR and non-HIR (HR, 1.22; 95% CI, 0.32 to 4.6) stage I grade 3 EECs. Patients with CN-H compared with non-CN-H EEC had worse PFS (HR, 5.67; 95% CI, 1.73 to 18.63) and OS (HR, 5.05; 95% CI, 1.13 to 22.5). CONCLUSION In surgically staged patients with stage I grade 3 EEC, PORTEC-1 and GOG-99 HIR criteria were not prognostic and did not identify CN-H patients. Patients with CN-H EEC had worse PFS and OS compared with those with other molecular subtypes. The integration of the molecular classification with recognized clinicopathologic factors may identify patients with higher-risk stage I grade 3 EEC who benefit from additional therapy.

High-Sensitivity Mutation Analysis of Cell-Free DNA for Disease Monitoring in Endometrial Cancer

Abstract Purpose: We sought to determine whether sequencing analysis of circulating cell-free DNA (cfDNA) in patients with prospectively accrued endometrial cancer captures the mutational repertoire of the primary lesion and allows for disease monitoring. Experimental Design: Peripheral blood was prospectively collected from 44 newly diagnosed patients with endometrial cancer over a 24-month period (i.e., baseline, postsurgery, every 6 months after). DNA from the primary endometrial cancers was subjected to targeted next-generation sequencing (NGS) of 468 cancer-related genes, and cfDNA to a high-depth NGS assay of 129 genes with molecular barcoding. Sequencing data were analyzed using validated bioinformatics methods. Results: cfDNA levels correlated with surgical stage in endometrial cancers, with higher levels of cfDNA being present in advanced-stage disease. Mutations in cfDNA at baseline were detected preoperatively in 8 of 36 (22%) patients with sequencing data, all of whom were diagnosed with advanced-stage disease, high tumor volume, and/or aggressive histologic type. Of the 38 somatic mutations identified in the primary tumors also present in the cfDNA assay, 35 (92%) and 38 (100%) were detected at baseline and follow-up, respectively. In 6 patients with recurrent disease, changes in circulating tumor DNA (ctDNA) fraction/variant allele fractions in cfDNA during follow-up closely mirrored disease progression and therapy response, with a lead time over clinically detected recurrence in two cases. The presence of ctDNA at baseline (P < 0.001) or postsurgery (P = 0.014) was significantly associated with reduced progression-free survival. Conclusions: cfDNA sequencing analysis in patients with endometrial cancer at diagnosis has prognostic value, and serial postsurgery cfDNA analysis enables disease and treatment response monitoring. See related commentary by Grant et al., p. 305

Microsatellite Instability–High Endometrial Cancers with MLH1 Promoter Hypermethylation Have Distinct Molecular and Clinical Profiles

Abstract Purpose: Microsatellite instability–high (MSI-H) endometrial carcinomas are underpinned by distinct mechanisms of DNA mismatch repair deficiency (MMR-D). We sought to characterize the clinical and genetic features of MSI-H endometrial cancers harboring germline or somatic mutations in MMR genes or MLH1 promoter hypermethylation (MLH1ph). Experimental Design: Of > 1,100 patients with endometrial cancer that underwent clinical tumor-normal sequencing, 184 had MSI-H endometrial cancers due to somatic MMR mutations or MLH1ph, or harbored pathogenic germline MMR mutations. Clinicopathologic features, mutational landscape, and tumor-infiltrating lymphocyte (TIL) scores were compared among MMR-D groups using nonparametric tests. Log-rank tests were used for categorical associations; Kaplan–Meier method and Wald test based on Cox proportional hazards models were employed for continuous variables and survival analyses. Results: Compared with patients with germline (n = 25) and somatic (n = 39) mutations, patients with MLH1ph endometrial cancers (n = 120) were older (P < 0.001), more obese (P = 0.001) and had more advanced disease at diagnosis (P = 0.025). MLH1ph endometrial cancers were enriched for JAK1 somatic mutations as opposed to germline MMR-D endometrial cancers which showed enrichment for pathogenic ERBB2 mutations. MLH1ph endometrial cancers exhibited lower tumor mutational burden and TIL scores compared with endometrial cancers harboring germline or somatic MMR mutations (P < 0.01). MLH1ph endometrial cancer patients had shorter progression-free survival (PFS) on univariate analysis, but in multivariable models, stage at diagnosis remained the only predictor of survival. For stage I/II endometrial cancer, two-year PFS was inferior for patients with MLH1ph endometrial cancers compared with germline and somatic MMR groups (70% vs. 100%, respectively). Conclusions: MLH1ph endometrial cancers likely constitute a distinct clinicopathologic entity compared with germline and somatic MMR-D ECs with potential treatment implications.

Impact of obesity and white adipose tissue inflammation on the omental microenvironment in endometrial cancer

BackgroundA complex relationship between adipose tissue and malignancy, involving an inflammatory response, has been reported. The goal of this work was to assess the prevalence of white adipose tissue (WAT) inflammation in patients with endometrial cancer (EC), and the association with circulating inflammation markers. Furthermore, the aim was to characterize the pathways activated in and the cell type composition of adipose tissue in patients with EC.MethodsAdipose tissue and blood samples were prospectively collected from 101 patients with EC at initial surgery. WAT inflammation was determined based on adipocytes surrounded by macrophages forming crown‐like structures. Circulating levels of metabolic syndrome–associated and inflammatory markers were quantified. RNA‐sequencing was performed on adipose samples (n = 55); differential gene expression, pathway, and cellular decomposition analyses were performed using state‐of‐the‐art bioinformatics methods.ResultsWAT inflammation was identified in 46 (45.5%) of 101 EC patients. Dyslipidemia, hypertension, and diabetes mellitus were significantly associated with WAT inflammation (p < .05). WAT inflammation was associated with greater body mass index (p < .001) and higher circulating levels of leptin, high‐sensitivity C‐reactive protein, and interleukin‐6, as well as lower levels of adiponectin and sex hormone–binding globulin (p < .05). Transcriptomic analysis demonstrated increased levels of proinflammatory and pro‐neoplastic–related gene expression in inflamed omental adipose tissue.ConclusionsWAT inflammation is associated with metabolic syndrome, obesity, and inflammatory markers, as well as increased expression of proinflammatory and proneoplastic genes.

Genomic Determinants of Early Recurrences in Low-Stage, Low-Grade Endometrioid Endometrial Carcinoma

Abstract Low-stage, low-grade endometrioid endometrial carcinoma (EEC), the most common histologic type of endometrial cancer, typically has a favorable prognosis. A subset of these cancers, however, displays an aggressive clinical course with early recurrences, including distant relapses. All statistical tests were 2-sided. Using a combination of whole-exome and targeted capture sequencing of 65 FIGO stage IA and IB grade 1 EECs treated with surgery alone, we demonstrate that chromosome 1q gain (odds ratio [OR] = 8.09, 95% confidence interval [CI] = 1.59 to 54.6; P = .02), PIK3CA mutation (OR = 9.16, 95% CI = 1.95 to 61.8; P = .01), and DNA mismatch repair-deficient molecular subtype (OR = 7.92, 95% CI = 1.44 to 87.6; P = .02) are independent predictors of early recurrences within 3 years in this patient population. Chromosome 1q gain was validated in an independent dataset of stage I grade 1 EECs subjected to whole-exome sequencing. Our findings expand on the repertoire of genomic parameters that should be considered in the evaluation of patients with low-stage, low-grade EEC.

Histopathologic features and molecular genetic landscape of HER2-amplified endometrial carcinomas

HER2 is an established therapeutic biomarker in advanced or recurrent endometrial serous carcinoma. Current clinical guidelines recommend HER2 testing exclusively in this endometrial carcinoma (EC) subtype; however, the full spectrum of ECs harboring HER2 amplification remains ill-defined. The present study characterizes the clinicopathologic and molecular features of HER2-amplified ECs across all histologic subtypes. Retrospective analysis of our institutional cohort of 2,042 ECs subjected to targeted clinical massively parallel sequencing identified 77 (3.8%) cases with HER2 amplification, a group comprised of serous (n = 29), endometrioid (low-grade, n = 2, high-grade, n = 1) and clear cell (n = 4) carcinomas, carcinosarcomas (n = 18) and high-grade ECs with ambiguous features (HGEC, n = 23). A co-existing TP53 mutation was identified in 94% (72/77) of HER2-amplified ECs. Other recurrent genetic alterations included amplification of CCNE1 (22%) and ERBB3 (10%), FBXW7 mutations or deletions (13%), and mutations in PIK3CA (40%) and PPP2R1A (13%). The HER2 immunohistochemistry score was 2+ or 3+ for all evaluable cases (n = 61). Apart from carcinosarcomas, which often showed lower HER2 expression, particularly in the sarcomatous component, HER2 immunohistochemical staining pattern and intensity were similar across EC subtypes. Intratumor heterogeneity in HER2 expression was common and correlated with genetic heterogeneity as detected by fluorescence in-situ hybridization. These results demonstrate the frequent co-occurrence of HER2 amplification with TP53 mutation and high-grade histology, rather than being specific to serous carcinoma, per se. Overall, these findings suggest that HER2 targeted therapy may be more broadly applicable to all high-grade EC histotypes and consideration should be given to expanding therapeutic eligibility.

Age-Related Germline Landscape of Endometrial Cancer: Focus on Early-Onset Cases

PURPOSE Early-onset endometrial cancer (eoEC) is increasing, and germline drivers may be enriched in younger patients. We sought to define germline pathogenic variants (gPVs) in those with EC by age. METHODS We identified patients with EC who underwent clinical tumor-normal sequencing from December 2014 to June 2021 and collected clinical variables. Logistic regression models evaluated associations between age at EC diagnosis and presence of gPV, biallelic inactivation, and Lynch Syndrome (LS). Age categories were defined as early-onset (eoEC, EC < 50 years) and late-onset (EC ≥ 70 years) and were compared with those diagnosed ages 50-69 years. RESULTS Among 1,625 patients with EC, the median age at diagnosis was 63 (range, 24-96) years. We observed gPV in 28 (16%) of 170 patients with eoEC, 152 (14%) of 1,066 patients diagnosed age 50-69 years, and 36 (9%) of 389 patients with late-onset EC ( P = .016). LS was enriched in eoEC, with 6.5% of patients diagnosed age <50 years having LS. In multivariable models compared with those with EC diagnosed age 50-69 years, eoEC was more likely to exhibit biallelic inactivation (odds ratio, 3.34 [95% CI, 1.44 to 7.35]) and be associated with LS (hazard ratio [HR], 3.49 [95% CI, 1.63 to 7.01]). Among early-onset EC, 14 (50%) of 28 gPV were high penetrance and 14 (50%) of 28 exhibited biallelic inactivation. However, heterogeneity was observed, and rates of gPV were 8.9% and 19%, biallelic inactivation was 0% and 11%, and LS was 2.2% and 8% in those diagnosed age <40 years and 40-49 years, respectively. CONCLUSION Rates of gPV, biallelic inactivation, and LS differ across age groups for EC, with high-penetrant genes driving tumorigenesis enriched in younger patients. However, very-early-onset EC may have different drivers and necessitates more research.

Factors associated with an inconclusive result from commercial homologous recombination deficiency testing in ovarian cancer

AbstractIntroductionHomologous recombination deficiency (HRD) testing is used to determine the appropriateness of poly ADP‐ribose polymerase inhibitors for patients with epithelial ovarian cancer and no germline/somatic BRCA1/2 alterations. Myriad MyChoice CDx reports a genomic instability score (GIS) to quantify the level of HRD, with a positive score defined as ≥42. The authors sought to define factors associated with obtaining an inconclusive HRD test result.MethodsGIS was retrieved for patients at their institution with epithelial ovarian cancer without germline/somatic BRCA1/2 deleterious alterations who underwent HRD testing from April 2020–August 2023. Clinical data were abstracted from the medical record.ResultsOf 477 HRD test results identified, 57 (12%) were inconclusive. High‐grade serous ovarian cancers had higher GIS than other histologic types (median 29 vs. 21, p < .001). Most HRD cases were of high‐grade serous histology; no cases with clear cell or endometrioid histology were HRD‐positive. On univariate analysis, interval versus primary cytoreductive surgery, other specimen sources versus surgical specimens, and chemotherapy exposure were risk factors for inconclusive HRD testing. On multivariable analysis, chemotherapy exposure, and tissue source were associated with an inconclusive test result, with surgical specimens more likely to yield a conclusive result than other sources (biopsy, cytology, other). Age, stage, self‐reported race, and histology were not associated with an inconclusive result.ConclusionsSurgical tissue was more likely to yield a conclusive HRD test result versus other sources of epithelial ovarian cancer tissue acquisition. When feasible, laparoscopic biopsy before initiation of neoadjuvant chemotherapy may increase the likelihood of obtaining interpretable HRD test results.

Germline Pathogenic Variants and Genetic Counseling by Ancestry in Patients With Epithelial Ovarian Cancer

Mutations in ovarian cancer risk genes are found in women of diverse ancestries, supporting genetic testing for ALL

Spectrum ofBRAFMutations and Gene Rearrangements in Ovarian Serous Carcinoma

PURPOSELow-grade serous carcinoma (LGSC) is a rare type of ovarian cancer, which commonly arises from serous borderline tumor (SBT) and is characterized by frequent activating mutations in the mitogen-activated protein kinase pathway, including BRAF. The BRAFV600Emutation is associated with improved prognosis in SBT and LGSC, and responses to BRAF inhibitor therapy have been reported. We sought to characterize the clinicopathologic and molecular features of BRAF-driven tubo-ovarian and primary peritoneal serous tumors.METHODSRetrospective analysis of our institutional cohort of SBTs (n = 22), LGSCs (n = 119) and high-grade serous carcinomas (HGSCs, n = 1,290) subjected to targeted massively parallel sequencing was performed to identify cases with BRAF genetic alterations. Putative BRAF rearrangements were confirmed using targeted RNA sequencing and/or fluorescence in situ hybridization (FISH). BRAFV600Eoncoprotein expression was assessed by immunohistochemistry on selected cases.RESULTSBRAF somatic genetic alterations were identified in 29 of 1,431 (2%) serous tumors and included mutations (n = 24), gene rearrangements (n = 3), and amplification (n = 2). BRAF mutations were more frequent in SBTs (7 of 22; 32%) compared with LGSCs (11 of 119; 9%, P = .009) and HGSCs (6 of 1,290; 0.5%; P < .0001, SBT/LGSC v HGSC). The BRAFV600Ehotspot mutation was most common (n = 16); however, other BRAF driver mutations were also detected (n = 8). BRAF mutations were often clonal or truncal in SBTs and LGSCs, but subclonal in most HGSCs. Pathogenic BRAF gene fusions were identified in LGSCs (n = 2) and HGSC (n = 1) and involved distinct fusion partners ( AGK, MKRN1, and AGAP3). Three patients with BRAF-mutant LGSC were treated with targeted mitogen-activated protein kinase inhibitors, one of whom was maintained on therapy for over 3 years with clinical benefit.CONCLUSIONRecognition of BRAF alterations beyond V600E mutation in LGSC may have clinical implications for appropriate targeted therapy selection.

Molecular Subclasses of Clear Cell Ovarian Carcinoma and Their Impact on Disease Behavior and Outcomes

Abstract Purpose: To identify molecular subclasses of clear cell ovarian carcinoma (CCOC) and assess their impact on clinical presentation and outcomes. Experimental Design: We profiled 421 primary CCOCs that passed quality control using a targeted deep sequencing panel of 163 putative CCOC driver genes and whole transcriptome sequencing of 211 of these tumors. Molecularly defined subgroups were identified and tested for association with clinical characteristics and overall survival. Results: We detected a putative somatic driver mutation in at least one candidate gene in 95% (401/421) of CCOC tumors including ARID1A (in 49% of tumors), PIK3CA (49%), TERT (20%), and TP53 (16%). Clustering of cancer driver mutations and RNA expression converged upon two distinct subclasses of CCOC. The first was dominated by ARID1A-mutated tumors with enriched expression of canonical CCOC genes and markers of platinum resistance; the second was largely comprised of tumors with TP53 mutations and enriched for the expression of genes involved in extracellular matrix organization and mesenchymal differentiation. Compared with the ARID1A-mutated group, women with TP53-mutated tumors were more likely to have advanced-stage disease, no antecedent history of endometriosis, and poorer survival, driven by their advanced stage at presentation. In women with ARID1A-mutated tumors, there was a trend toward a lower rate of response to first-line platinum-based therapy. Conclusions: Our study suggests that CCOC consists of two distinct molecular subclasses with distinct clinical presentation and outcomes, with potential relevance to both traditional and experimental therapy responsiveness. See related commentary by Lheureux, p. 4838

MAPK Pathway Genetic Alterations Are Associated with Prolonged Overall Survival in Low-Grade Serous Ovarian Carcinoma

Abstract Purpose: To characterize the somatic mutational landscape, investigate associations between genetic alterations and clinical outcomes, and determine the prevalence of pathogenic germline mutations in low-grade serous ovarian carcinomas (LGSC). Experimental Design: Patients with LGSC tumors who underwent panel-based sequencing of up to 505 genes were identified. Data on somatic and germline mutations; copy-number alterations; and clinicopathologic features, including age at diagnosis, platinum sensitivity, and overall survival (OS), were collected. Results: Following central pathology rereview, 119 patients with LGSC were identified for analysis. Of these, 110 (92%) had advanced-stage disease (stages III/IV). Somatic KRAS (33%), NRAS (11%), EIF1AX (10%), and BRAF (11%) alterations were the most common; MAPK pathway alterations were found in 60% (n = 71) of LGSCs. KRAS mutations were significantly associated with age at diagnosis more than 50 years (P = 0.02) and platinum-sensitive disease (P = 0.03). On multivariate analysis, MAPK pathway alterations (P = 0.02) and platinum sensitivity (P = 0.005) were significantly associated with improved OS. Seventy-nine patients (66%) underwent germline genetic testing; seven pathogenic germline mutations were identified: MUTYH (n = 2), BAP1 (n = 1), RB1 (n = 1), CHEK2 (n = 1), APC (n = 1), and FANCA (n = 1). There were no germline BRCA1/2 mutations. One germline MUTYH-associated LGSC harbored loss-of-heterozygosity at the MUTYH locus, and the patient with the germline BAP1 mutation also harbored a somatic BAP1 frameshift mutation. Conclusions: This study showed that MAPK pathway alterations in LGSC, including KRAS mutations, are independently associated with platinum sensitivity and prolonged survival. Germline data, which were limited, identified few pathogenic germline mutations in patients with LGSC. See related commentary by Veneziani and Oza, p. 4357

Vulvar angiomyofibroblastoma is molecularly defined by recurrent MTG1‐CYP2E1 fusions

Angiomyofibroblastoma (AMF), a rare benign vulvovaginal mesenchymal tumour, poses a diagnostic challenge due to histologic and immunohistochemical overlap with other vulvar mesenchymal tumours. Recently, MTG1‐CYP2E1 fusion transcripts were reported in 5/5 AMFs; no other genetic alterations have been described to date. Herein, we sought to investigate the frequency of the MTG1‐CYP2E1 fusion and the presence of other potential genetic alterations in a cohort of AMFs (n = 7, patient age range: 28–49 years). Tumours demonstrated classic morphologic features including alternating hypo/hypercellular areas, capillary channels surrounded by epithelioid/spindled tumour cells, and variable amounts of mature adipose tissue. reverse transcription‐polymerase chain reaction (RT‐PCR) for MTG1‐CYP2E1 fusion, performed in all seven cases, showed the fusion transcript in five of six cases (one case with technical failure). Two tumours, including the one lacking the fusion, were subjected to targeted next‐generation sequencing (104 genes) and a sarcoma fusion assay (28 genes); the fusion negative AMF also underwent RNA sequencing. No additional mutations, copy number alterations, or fusion genes were identified with the assays employed. We conclude that the majority of AMFs harbour recurrent MTG1‐CYP2E1 fusion transcripts and identification of this fusion may aid in the diagnosis.

Genomic characterization of small cell carcinomas of the uterine cervix

Small cell carcinoma (SCC) of the uterine cervix is a rare and aggressive form of neuroendocrine carcinoma, which resembles small cell lung cancer (SCLC) in its histology and poor survival rate. Here, we sought to define the genetic underpinning of SCCs of the uterine cervix and compare their mutational profiles with those of human papillomavirus (HPV)‐positive head and neck squamous cell carcinomas, HPV‐positive cervical carcinomas, and SCLCs using publicly available data. Using a combination of whole‐exome and targeted massively parallel sequencing, we found that the nine uterine cervix SCCs, which were HPV18‐positive (n = 8) or HPV16‐positive (n = 1), harbored a low mutation burden, few copy number alterations, and other than TP53 in two cases no recurrently mutated genes. The majority of mutations were likely passenger missense mutations, and only few affected previously described cancer‐related genes. Using RNA‐sequencing, we identified putative viral integration sites on 18q12.3 and on 8p22 in two SCCs of the uterine cervix. The overall nonsilent mutation rate of uterine cervix SCCs was significantly lower than that of SCLCs, HPV‐driven cervical adeno‐ and squamous cell carcinomas, or HPV‐positive head and neck squamous cell carcinomas. Unlike SCLCs, which are reported to harbor almost universal TP53 and RB1 mutations and a dominant tobacco smoke‐related signature 4, uterine cervix SCCs rarely harbored mutations affecting these genes (2/9, 22% TP53; 0% RB1) and displayed a dominant aging (67%) or APOBEC mutational signature (17%), akin to HPV‐driven cancers, including cervical adeno‐ and squamous cell carcinomas and head and neck squamous cell carcinomas. Taken together, in contrast to SCLCs, which are characterized by highly recurrent TP53 and RB1 alterations, uterine cervix SCCs were positive for HPV leading to inactivation of the suppressors p53 and RB, suggesting that these SCCs are convergent phenotypes.

Assessing the Genomic Landscape of Cervical Cancers: Clinical Opportunities and Therapeutic Targets

Abstract Purpose: Tumor genomic profiling is increasingly used to guide treatment strategy in patients with cancer. We integrated tumor genomic, clinical demographic, and treatment response data to assess how prospective tumor-normal sequencing impacted treatment selection in patients with cervical cancer. Experimental Design: Cervical cancers were prospectively analyzed using the MSK-IMPACT (Memorial Sloan Kettering Cancer Center – Integrated Mutation Profiling of Actionable Cancer Targets) next-generation sequencing panel. Clinical data, including histology, stage at diagnosis, treatment history, clinical trial enrollment and outcomes, date of last follow-up, and survival status were obtained from medical records. Results: A total of 177 patients with cervical cancer (squamous, 69; endocervical adenocarcinoma, 50; gastric type, 22; adenosquamous, 21; and other, 15) underwent MSK-IMPACT testing. The most prevalent genomic alterations were somatic mutations or amplifications in PIK3CA (25%), ERBB2 (12%), KMT2C (10%), and KMT2D (9%). Furthermore, 13% of patients had high tumor mutational burden (TMB >10 mut/Mb), 3 of which were also microsatellite instability–high (MSI-H). Thirty-seven percent of cases had at least one potentially actionable alteration designated as a level 3B mutational event according to the FDA-recognized OncoKB tumor mutation database and treatment classification system. A total of 30 patients (17%) were enrolled on a therapeutic clinical trial, including 18 (10%) who were matched with a study based on their MSK-IMPACT results. Twenty patients (11%) participated in an immune checkpoint inhibition study for metastatic disease; 2 remain progression free at >5 years follow-up. Conclusions: Tumor genomic profiling can facilitate the selection of targeted/immunotherapies, as well as clinical trial enrollment, for patients with cervical cancer.

Ovarian cancer mutational processes drive site-specific immune evasion

High-grade serous ovarian cancer is a genomically complex malignancy. Here the authors integrate whole-genome sequencing, single-cell RNA sequencing, digital histopathology and multiplexed immunofluorescence across 160 tumour sites from 42 patients, revealing that mutational processes shape site-specific immune evasion.

Ongoing genome doubling shapes evolvability and immunity in ovarian cancer

Single-cell whole-genome sequencing of 30,260 tumour genomes from 70 samples across 41 patients in the SPECTRUM cohort reveals that ongoing whole-genome doubling drives tumour evolvability and immune evasion in high-grade serous ovarian cancer.

Tracking clonal evolution during treatment in ovarian cancer using cell-free DNA

Emergence of drug resistance is the main cause of therapeutic failure in patients with high-grade serous ovarian cancer (HGSOC)

Nivolumab for mismatch-repair-deficient or hypermutated gynecologic cancers: a phase 2 trial with biomarker analyses

AbstractProgrammed death-1 (PD-1) inhibitors are approved for therapy of gynecologic cancers with DNA mismatch repair deficiency (dMMR), although predictors of response remain elusive. We conducted a single-arm phase 2 study of nivolumab in 35 patients with dMMR uterine or ovarian cancers. Co-primary endpoints included objective response rate (ORR) and progression-free survival at 24 weeks (PFS24). Secondary endpoints included overall survival (OS), disease control rate (DCR), duration of response (DOR) and safety. Exploratory endpoints included biomarkers and molecular correlates of response. The ORR was 58.8% (97.5% confidence interval (CI): 40.7–100%), and the PFS24 rate was 64.7% (97.5% one-sided CI: 46.5–100%), meeting the pre-specified endpoints. The DCR was 73.5% (95% CI: 55.6–87.1%). At the median follow-up of 42.1 months (range, 8.9–59.8 months), median OS was not reached. One-year OS rate was 79% (95% CI: 60.9–89.4%). Thirty-two patients (91%) had a treatment-related adverse event (TRAE), including arthralgia (n = 10, 29%), fatigue (n = 10, 29%), pain (n = 10, 29%) and pruritis (n = 10, 29%); most were grade 1 or grade 2. Ten patients (29%) reported a grade 3 or grade 4 TRAE; no grade 5 events occurred. Exploratory analyses show that the presence of dysfunctional (CD8+PD-1+) or terminally dysfunctional (CD8+PD-1+TOX+) T cells and their interaction with programmed death ligand-1 (PD-L1)+ cells were independently associated with PFS24. PFS24 was associated with presence of MEGF8 or SETD1B somatic mutations. This trial met its co-primary endpoints (ORR and PFS24) early, and our findings highlight several genetic and tumor microenvironment parameters associated with response to PD-1 blockade in dMMR cancers, generating rationale for their validation in larger cohorts.ClinicalTrials.gov identifier: NCT03241745.

Molecular Classification in Relation to Prevention of Endometrial Cancer Recurrence and Lifestyle Factors

Endometrial cancer (EC) is one of the most prevalent cancers in women worldwide with a significantly increasing incidence, especially in developed countries. One of the reasons for the increase in the incidence of this disease is the rising incidence of obesity as the biggest risk factor for the development of this disease. Other important risk factors are hypertension, diabetes mellitus and the general ageing of the population. These risk factors are not only associated with a higher risk of developing the disease, but also, for example, with post-operative complications affecting the quality of life of patients after surgery. The molecular classification of endometrial cancer, which has been introduced into clinical practice in recent years, is currently helping physicians to make treatment decisions for individual patients and predict prognosis. In this project, we would like to focus on the relationship of this molecular classification with genomic mutational signatures detected by whole-exome sequencing and their association with lifestyle risk factors for endometrial cancer (obesity - BMI, hypertension, diabetes mellitus), including the extent of staging lymphadenectomy. Identification and detailed analysis of dominant mutational profiles associated with a specific molecular subtype of EC and their influence on the presence of lifestyle risk factors may have a major impact on both disease development and prevention of disease recurrence. The possible relationship of the mutational profile with the extent of staging lymphadenectomy may help in deciding the extent of this surgical procedure, which subsequently affects the quality of life of patients, especially in patients with high BMI. Given the widespread prevalence of lifestyle risk factors in the developed world, a detailed understanding of the relationship between the genetic profile, its alterations and the prevalence of these risk factors, with potentially major implications for treatment success, is crutial.