Andrew Berchuck

Cellular origins of mucinous ovarian carcinoma

AbstractMucinous ovarian carcinoma (MOC) is a rare histotype of epithelial ovarian cancer. Its origins are obscure: while many mucinous tumours in the ovary are metastases from the gastrointestinal tract, MOC can occur as an ovarian primary; however, the cell of origin is not well established. In this review we summarise the pathological, epidemiological, and molecular evidence for the cellular origins of MOC. We propose a model for the origins of the various tumours of the ovary with mucinous differentiation. We distinguish Müllerian from gastrointestinal‐type mucinous differentiation. A small proportion of the latter arise from teratoma and a distinct terminology has been proposed. Other gastrointestinal mucinous tumours are associated with Brenner tumours and arise from their associated benign lesions, Walthard nests. The remaining mucinous tumours develop either through mucinous metaplasia in established Müllerian tumours or with even greater plasticity through gastrointestinal metaplasia of epithelial or mesothelial ovarian inclusions. This model remains to be validated and mechanistically understood and we discuss future research directions. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Molecular Subtypes of High-Grade Serous Ovarian Cancer across Racial Groups and Gene Expression Platforms

Abstract Background: High-grade serous carcinoma (HGSC) gene expression subtypes are associated with differential survival. We characterized HGSC gene expression in Black individuals and considered whether gene expression differences by self-identified race may contribute to poorer HGSC survival among Black versus White individuals. Methods: We included newly generated RNA sequencing data from Black and White individuals and array-based genotyping data from four existing studies of White and Japanese individuals. We used K-means clustering, a method with no predefined number of clusters or dataset-specific features, to assign subtypes. Cluster- and dataset-specific gene expression patterns were summarized by moderated t-scores. We compared cluster-specific gene expression patterns across datasets by calculating the correlation between the summarized vectors of moderated t-scores. After mapping to The Cancer Genome Atlas–derived HGSC subtypes, we used Cox proportional hazards models to estimate subtype-specific survival by dataset. Results: Cluster-specific gene expression was similar across gene expression platforms and racial groups. Comparing the Black population with the White and Japanese populations, the immunoreactive subtype was more common (39% vs. 23%–28%) and the differentiated subtype was less common (7% vs. 22%–31%). Patterns of subtype-specific survival were similar between the Black and White populations with RNA sequencing data; compared with mesenchymal cases, the risk of death was similar for proliferative and differentiated cases and suggestively lower for immunoreactive cases [Black population HR = 0.79 (0.55, 1.13); White population HR = 0.86 (0.62, 1.19)]. Conclusions: Although the prevalence of HGSC subtypes varied by race, subtype-specific survival was similar. Impact: HGSC subtypes can be consistently assigned across platforms and self-identified racial groups.

Concurrent RB1 Loss and BRCA Deficiency Predicts Enhanced Immunologic Response and Long-term Survival in Tubo-ovarian High-grade Serous Carcinoma

Abstract Purpose: The purpose of this study was to evaluate RB1 expression and survival across ovarian carcinoma histotypes and how co-occurrence of BRCA1 or BRCA2 (BRCA) alterations and RB1 loss influences survival in tubo-ovarian high-grade serous carcinoma (HGSC). Experimental Design: RB1 protein expression was classified by immunohistochemistry in ovarian carcinomas of 7,436 patients from the Ovarian Tumor Tissue Analysis consortium. We examined RB1 expression and germline BRCA status in a subset of 1,134 HGSC, and related genotype to overall survival (OS), tumor-infiltrating CD8+ lymphocytes, and transcriptomic subtypes. Using CRISPR-Cas9, we deleted RB1 in HGSC cells with and without BRCA1 alterations to model co-loss with treatment response. We performed whole-genome and transcriptome data analyses on 126 patients with primary HGSC to characterize tumors with concurrent BRCA deficiency and RB1 loss. Results: RB1 loss was associated with longer OS in HGSC but with poorer prognosis in endometrioid ovarian carcinoma. Patients with HGSC harboring both RB1 loss and pathogenic germline BRCA variants had superior OS compared with patients with either alteration alone, and their median OS was three times longer than those without pathogenic BRCA variants and retained RB1 expression (9.3 vs. 3.1 years). Enhanced sensitivity to cisplatin and paclitaxel was seen in BRCA1-altered cells with RB1 knockout. Combined RB1 loss and BRCA deficiency correlated with transcriptional markers of enhanced IFN response, cell-cycle deregulation, and reduced epithelial–mesenchymal transition. CD8+ lymphocytes were most prevalent in BRCA-deficient HGSC with co-loss of RB1. Conclusions: Co-occurrence of RB1 loss and BRCA deficiency was associated with exceptionally long survival in patients with HGSC, potentially due to better treatment response and immune stimulation.

Homologous Recombination Deficiency and Survival in Ovarian High-Grade Serous Carcinoma by Self-Reported Race

Abstract Background: Half of ovarian high-grade serous carcinomas (HGSC) have homologous recombination deficiency (HRD). However, HRD is not well characterized in Black individuals who experience worse survival after a diagnosis of HGSC. The objective of this study was to characterize ovarian HGSC HRD and examine its association with survival by self-reported race. Methods: HRD features were identified using matched tumor–normal whole-exome and RNA sequencing in an HGSC cohort. We calculated age- and stage-adjusted HR and 95% confidence intervals (CI) for survival, comparing individuals with a feature to those without, separately by self-reported race. Results: Any HRD was associated with a 32% reduced risk of death in Black individuals compared with a 62% reduction in White individuals (Black HR = 0.68; 95% CI, 0.43–1.09; White HR = 0.38; 95% CI, 0.14–1.04). More of the germline and somatic variants detected among Black individuals were unannotated or variants of uncertain significance (VUS; germline 65% vs. 45%; somatic 62% vs. 50%). Black individuals with germline unannotated/VUS were more likely to have tumors with HRD scarring and a first-degree family history of breast or ovarian cancer compared with those without (HRD scar 71.4% vs. 49.6%; family history 68.4% vs. 34.6%). Conclusions: HRD testing informs precision-based medicine approaches that improve outcomes, but a higher proportion of VUS among Black individuals may complicate referral for such care leading to worse outcomes for Black individuals. Impact: Our findings emphasize the importance of recruiting diverse individuals in genomics research and better characterizing VUS.

Health Care Access Dimensions and Racial Disparities in End-of-Life Care Quality among Patients with Ovarian Cancer

Abstract This study investigated the association between health care access (HCA) dimensions and racial disparities in end-of-life (EOL) care quality among non-Hispanic Black (NHB), non-Hispanic White (NHW), and Hispanic patients with ovarian cancer. This retrospective cohort study used the Surveillance, Epidemiology, and End Results–linked Medicare data for women diagnosed with ovarian cancer from 2008 to 2015, ages 65 years and older. Health care affordability, accessibility, and availability measures were assessed at the census tract or regional levels, and associations between these measures and quality of EOL care were examined using multivariable-adjusted regression models, as appropriate. The final sample included 4,646 women [mean age (SD), 77.5 (7.0) years]; 87.4% NHW, 6.9% NHB, and 5.7% Hispanic. In the multivariable-adjusted models, affordability was associated with a decreased risk of intensive care unit stay [adjusted relative risk (aRR) 0.90, 95% confidence interval (CI): 0.83–0.98] and in-hospital death (aRR 0.91, 95% CI: 0.84–0.98). After adjustment for HCA dimensions, NHB patients had lower-quality EOL care compared with NHW patients, defined as: increased risk of hospitalization in the last 30 days of life (aRR 1.16, 95% CI: 1.03–1.30), no hospice care (aRR 1.23, 95% CI: 1.04–1.44), in-hospital death (aRR 1.27, 95% CI: 1.03–1.57), and higher counts of poor-quality EOL care outcomes (count ratio:1.19, 95% CI: 1.04–1.36). HCA dimensions were strong predictors of EOL care quality; however, racial disparities persisted, suggesting that additional drivers of these disparities remain to be identified. Significance: Among patients with ovarian cancer, Black patients had lower-quality EOL care, even after adjusting for three structural barriers to HCA, namely affordability, availability, and accessibility. This suggests an important need to investigate the roles of yet unexplored barriers to HCA such as accommodation and acceptability, as drivers of poor-quality EOL care among Black patients with ovarian cancer.