Fergus J. Couch

Dual FAK and EPHA2 targeting by brigatinib tackles PARP inhibitor adaptive survival response in high-grade serous ovarian cancer

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPis) are an important therapy for high-grade serous ovarian cancer (HGSOC). However, PARPi resistance frequently emerges, necessitating previously unrecognized approaches to improve HGSOC responses. Here, we showed that the anaplastic lymphoma kinase (ALK) inhibitor brigatinib enhances PARPi activity in HGSOC cells by disrupting an adaptive survival mechanism orchestrated by Fos-related antigen 1 (FRA1) in response to PARPi. This effect of brigatinib occurred through an ALK-independent pathway, wherein brigatinib induced a dual blockade of focal adhesion kinase (FAK) and EPH receptor A2 (EPHA2) tyrosine kinases, leading to the suppression of protein kinase B (Akt) and extracellular-regulated kinase (ERK) signaling accompanied by disruption of a phosphorylation event crucial for FRA1 protein stability. Moreover, in HGSOC patient-derived xenograft (PDX) models, brigatinib and PARPi combination therapy induced tumor regression and improved overall survival compared with PARPi alone, particularly in models with high FAK and EPHA2. These findings support dual targeting of FAK and EPHA2 as a strategy to achieve effective and durable PARPi responses and identify a promising biomarker-based combinatorial approach using brigatinib and PARPi for HGSOC, particularly the subset characterized by high FAK and EPHA2.

Germline–Somatic Interactions in BRCA-Associated Cancers: Unique Molecular Profiles and Clinical Outcomes Linking ATM to TP53 Synthetic Essentiality

Abstract Purpose: Germline alterations in homologous recombination repair (gHRR) genes affect the pathogenesis, treatment options, and survival of patients with cancer. However, distinct gHRR gene alterations may differentially affect treatment response and oncogenic signaling. In this study, we interrogated genomic and transcriptomic data and assessed clinical outcomes of patients with gHRR mutations across four BRCA-associated cancers (breast, ovarian, pancreatic, and prostate cancers) to identify therapeutic vulnerabilities. Experimental Design: We assessed 24,309 patients undergoing matched tumor/normal next-generation DNA and RNA sequencing. Annotated gHRR gene variants [germline BRCA1, germline BRCA2, germline PALB2, germline ATM (gATM), and germline CHEK2] were analyzed. HRs were used to assess survival outcomes comparing germline versus sporadic groups. Somatic alterations and their frequencies were compared across gHRR-altered groups. Differential gene expression and gene set enrichment analysis were used to compare transcriptomic profiles. Results: Somatic TP53 mutations were depleted in gATM carriers (P < 0.05) across all four BRCA-associated cancers by up to 2.5-fold. Tumors with germline BRCA1/2 mutations were associated with improved survival in patients with ovarian cancer and had consistent enrichment of TP53 mutations in all four cancers. gATM mutations displayed elevated p53 transcriptional activity in all four cancers, with significance reached in breast and prostate cancers (P < 0.01). In breast, ovarian, and prostate cancers, gATM tumors demonstrated significantly increased inflammatory pathways (P < 0.001). Finally, using gene dependency data, we found that cell lines that were highly dependent on ATM were co-dependent on canonical p53 function. Conclusions: gATM-associated cancers seem to require intact p53 activity and this synthetic essentiality may be used to guide targeted therapies that perturb canonical TP53 function.

Physical Activity During Adolescence and Early-adulthood and Ovarian Cancer Among Women with a BRCA1 or BRCA2 Mutation

Abstract In the general population, physical activity has been associated with a lower risk of several cancers; however, the evidence for ovarian cancer is not clear. It is suggested that early-life physical activity may differentially impact risk. Whether this is true among women at high risk due to a pathogenic variant (mutation) in the BRCA1 or BRCA2 genes has not been evaluated. Thus, we performed a matched case–control study to evaluate the association between adolescent and early-adulthood physical activity and ovarian cancer. BRCA mutation carriers who completed a research questionnaire on various exposures and incident disease and with data available on physical activity were eligible for inclusion. Self-reported activity at ages 12–13, 14–17, 18–22, 23–29, and 30–34 was used to calculate the average metabolic equivalent of task (MET)-hours/week for moderate, vigorous, and total physical activity during adolescence (ages 12–17) and early-adulthood (ages 18–34). Conditional logistic regression was used to estimate the OR and 95% confidence intervals (CI) of invasive ovarian cancer associated with physical activity. This study included 215 matched pairs (mean age = 57.3). There was no association between total physical activity during adolescence (ORhigh vs. low = 0.91; 95% CI: 0.61–1.36; Ptrend = 0.85), early-adulthood (ORhigh vs. low = 0.78; 95% CI: 0.51–1.20; Ptrend = 0.38) and overall (ORhigh vs. low = 0.81; 95% CI: 0.54–1.23; Ptrend = 0.56) and ovarian cancer. Findings were similar for moderate (Ptrend ≥ 0.25) and vigorous (Ptrend ≥ 0.57) activity. These findings do not provide evidence for an association between early-life physical activity and BRCA-ovarian cancer; however, physical activity should continue to be encouraged to promote overall health. Significance: In this matched case–control study, we observed no association between physical activity during adolescence or early-adulthood and subsequent risk of ovarian cancer. These findings do not provide evidence for an association between early-life physical activity and BRCA-ovarian cancer; however, being active remains important to promote overall health and well-being.

Risk of Breast Cancer After Ovarian Cancer in Women With a Pathogenic/Likely Pathogenic Variant in BRCA1 or BRCA2

PURPOSE BRCA carriers face high risks of developing both breast and ovarian/fallopian tube cancers (hereafter referred to as ovarian ). Among BRCA carriers with ovarian cancer, it is not clear whether the risk of breast cancer is sufficiently high that risk-reducing mastectomy should be offered. This study aimed to assess the risk of breast cancer BRCA carriers after a diagnosis of ovarian cancer. METHODS We included women with a pathogenic/likely pathogenic variant in BRCA1 or BRCA2 , a diagnosis of ovarian cancer, and no other cancer history and no risk-reducing bilateral mastectomy. Women were followed for incident breast cancer from the date of ovarian cancer diagnosis or the date of baseline questionnaire, whichever came last. The 5-, 10-, and 15-year cumulative risks of breast cancer were compared for women with ovarian cancer and an age-matched set of control women without ovarian cancer. RESULTS A total of 960 participants with ovarian cancer were identified (814 BRCA1 and 146 BRCA2 carriers). After a mean follow-up of 4.9 years, 41 women (4.3%) developed breast cancer, at a mean age at diagnosis of 57.5 years (range, 39-74). Actuarial cumulative breast cancer risks after ovarian cancer were 4.4%, 8.9%, and 11.5% at 5, 10, and 15 years, respectively. Only three breast cancer–related deaths occurred. Among 741 age-matched BRCA carriers without ovarian cancer, actuarial cumulative risks of breast cancer were 20.9%, 38.6%, and 47.2% at 5, 10, and 15 years, respectively. The hazard ratio for breast cancer, after an ovarian cancer diagnosis, compared with no ovarian cancer, was 0.18 ([95% CI, 0.12 to 0.27]; P < .0001). CONCLUSION After ovarian cancer, BRCA carriers have a relatively low risk of breast cancer. Risk-reducing mastectomy should not be recommended routinely, but might be considered for long-term survivors. Magnetic resonance imaging surveillance and/or mammography is a realistic alternative.

Germline Mutations in 12 Genes and Risk of Ovarian Cancer in Three Population-Based Cohorts

Abstract Background: With the widespread use of multigene panel genetic testing, population-based studies are necessary to accurately assess penetrance in unselected individuals. We evaluated the prevalence of germline pathogenic or likely pathogenic variants (mutations) in 12 cancer-predisposition genes and associations with ovarian cancer risk in three population-based prospective studies [Nurses’ Health Study (NHS), NHSII, Cancer Prevention Study II]. Methods: We included women with epithelial ovarian or peritoneal cancer (n = 776) and controls who were alive and had at least one intact ovary at the time of the matched case diagnosis (n = 1,509). Germline DNA was sequenced for mutations in 12 genes. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for ovarian cancer risk by mutation status. Results: The mutation frequency across all 12 genes was 11.2% in cases and 3.3% in controls (P < 0.0001). BRCA1 and BRCA2 were the most frequently mutated (3.5% and 3.8% of cases and 0.3% and 0.5% of controls, respectively) and were associated with increased ovarian cancer risk [OR, BRCA1 = 12.38; 95% confidence interval (CI) = 4.72–32.45; OR, BRCA2 = 9.18; 95% CI = 3.98–21.15]. Mutation frequencies for the other genes were ≤1.0% and only PALB2 was significantly associated with risk (OR = 5.79; 95% CI = 1.09–30.83). There was no difference in survival for women with a BRCA germline mutation versus no mutation. Conclusions: Further research is needed to better understand the role of other mutations in ovarian cancer among unselected populations. Impact: Our data support guidelines for germline genetic testing for BRCA1 and BRCA2 among women diagnosed with epithelial ovarian cancer; testing for PALB2 may be warranted.

Variants of uncertain clinical significance in hereditary breast and ovarian cancer genes: best practices in functional analysis for clinical annotation

Germline DNA tests to identify pathogenic variants in genes linked to hereditary breast and ovarian cancer susceptibility have become widely available. However, the clinical utility of genetic testing depends on reliable evidence-based classification of sequence variants. Determination of pathogenicity traditionally relies on painstaking pedigree-based segregation analyses. However, the rapid increase in usage of germline DNA tests has led to the discovery of a large number of variants of uncertain clinical significance (VUS). For most VUS there is insufficient information for segregation analysis and therefore assessment of functional consequences is increasingly being used to support clinical annotation. Functional assays need to be accurate, robust, and reproducible to be used for clinical purposes. Here we use the lessons learned from

Bilateral Oophorectomy and the Risk of Breast Cancer in BRCA1 Mutation Carriers: A Reappraisal

Abstract Background: The lack of consensus on whether bilateral oophorectomy impacts risk of developing breast cancer among BRCA1 mutation carriers might be attributed to various biases, specifically, cancer-induced testing bias due to inclusion of prevalent cases. We conducted two complementary matched case–control analyses to evaluate the association of oophorectomy and BRCA1 breast cancer. Methods: A research questionnaire was administered every two years to collect information on exposures and disease. In the first analysis, we limited the study to prevalent breast cancer cases (diagnosed prior to study entry; n = 2,962) who were matched to controls on year of birth and country of residence (n = 4,358). In the second approach, we limited to 330 incident cases (diagnosed in the follow-up period) and 1,548 matched controls. Conditional logistic regression was used to estimate the adjusted odds ratios (OR) and 95% confidence intervals (CI) of invasive breast cancer. Results: In the first approach, there was a significant inverse association between oophorectomy and the risk of developing breast cancer [OR = 0.43; 95% confidence interval (CI), 0.34–0.55; P < 00001]. In the second approach, there was no association between oophorectomy and risk (OR = 1.21; 95% CI, 0.87–1.70; P = 0.26). Conclusions: The inclusion of women with a personal history of breast cancer prior to ascertainment likely impacts upon the association of oophorectomy and BRCA1 breast cancer risk. Impact: Oophorectomy is unlikely a determinant of breast cancer risk in BRCA1 mutation carriers but should be offered at age 35 to reduce the risk of ovarian and fallopian tube cancer.

Functional evaluation and clinical classification of BRCA2 variants

Germline BRCA2 loss-of function variants, which can be identified through clinical genetic testing, predispose to several cancers