Extended panel testing in ovarian cancer reveals BRIP1 as the third most important predisposition gene.

PURPOSE: The prevalence of germline pathogenic variants (PVs) in homologous recombination repair (HRR) and Lynch syndrome (LS) genes in ovarian cancer (OC) is uncertain. METHODS: An observational study reporting the detection rate of germline PVs in HRR and LS genes in all OC cases tested in the North West Genomic Laboratory Hub between September 1996 and May 2024. Effect sizes are reported using odds ratios (ORs) and 95% confidence intervals (95% CI) for unselected cases tested between April 2021 and May 2024 versus 50703 controls from the Breast Cancer Risk after Diagnostic Gene Sequencing study. RESULTS: 2934 women were tested for BRCA1/2 and 433 (14.8%) had a PV. In up to 1572 women tested for PVs in non-BRCA1/2 HRR genes, detection rates were PALB2=0.8%, BRIP1=1.1%, RAD51C=0.4% and RAD51D=0.4%. In 940 unselected cases, BRIP1 (OR=8.7, 95% CI 4.6-15.8) was the third commonest OC predisposition gene followed by RAD51C (OR=8.3, 95% CI 3.1-23.1), RAD51D (OR=6.5, 95% CI 2.1-19.7) and PALB2 (OR=3.9, 95% CI 1.5-10.3). No PVs in LS genes were detected in unselected cases. CONCLUSIONS: Panel testing in OC resulted in a detection rate of 2-3% for germline PVs in non-BRCA1/2 HRR genes, with the largest contributor being BRIP1. Screening for LS in unselected cases of OC is unnecessary.

Once daily cediranib and weekly paclitaxel to prevent malignant bowel obstruction in at-risk patients with platinum-resistant ovarian cancer (CEBOC): a single-arm, phase II safety trial.

OBJECTIVE: Cytotoxic chemotherapy for ovarian cancer can be augmented by co-administration of vascular endothelial growth factor inhibitors but these are contraindicated in patients with bowel obstruction due to the risk of gastrointestinal perforation. We evaluated the safety and feasibility of paclitaxel plus cediranib to treat patients with platinum-resistant ovarian cancer at risk of malignant bowel obstruction. METHODS: A phase II trial included eligible patients between March 2018 and February 2021, identified by clinical symptoms and radiographic risk factors for malignant bowel obstruction. Cediranib (20 mg/day) was added to paclitaxel (70 mg/m2/week) within 9 weeks of starting paclitaxel if pretreatment bowel symptoms had improved. The primary endpoint was the number of patients treated for ≥5 days with cediranib that were free of grade 3-5 gastrointestinal perforation or fistula. Secondary endpoints were hospitalization for bowel obstruction, grade ≥3 adverse events, treatment compliance assessed by relative dose intensity, objective response, progression-free survival, and overall survival. RESULTS: Thirty patients were recruited. Of these, 12 received paclitaxel alone and 17 received paclitaxel and cediranib in combination. One patient died before starting treatment. No patient developed a grade 3-5 gastrointestinal perforation or fistula (one sided 95% confidence interval (CI) upper limit 0.16). One patient required hospitalization for bowel obstruction but recovered with conservative management. The most common cediranib-related grade ≥3 adverse events were fatigue (3/17), diarrhorea (2/17), and hypomagnesemia (2/17). Relative dose intensity for paclitaxel was 90% (interquartile range (IQR) 85-100%; n=29) and for cediranib 88% (IQR 76-93%; n=17). The objective response in patients who received paclitaxel and cediranib was 65.0% (one complete and 10 partial responses). Median progression-free survival was 6.9 months (95% CI 4.4-11.5 months; n=17) and overall survival was 19.4 months (95% CI 10.1-20.4 months; n=17). Median follow-up was 12.4 months (8.9-not reached; n=17). CONCLUSIONS: The unexpectedly high withdrawal rate during paclitaxel alone, before introducing cediranib, meant we were unable to definitely conclude that paclitaxel plus cediranib did not cause gastrointestinal perforation or fistula. The regimen was however tolerated. TRIAL REGISTRATION NUMBER: EudraCT 2016-004618-93.

Real-World Concordance between Germline and Tumour BRCA1/2 Status in Epithelial Ovarian Cancer.

Patients diagnosed with epithelial ovarian cancer may undergo reflex tumour BRCA1/2 testing followed by germline BRCA1/2 testing in patients with a positive tumour test result. This testing model relies on tumour BRCA1/2 tests being able to detect all types of pathogenic variant. We analysed germline and tumour BRCA1/2 test results from patients treated for epithelial ovarian cancer at our specialist oncological referral centre. Tumour BRCA1/2 testing was performed using the next-generation sequencing (NGS)-based myChoice® companion diagnostic (CDx; Myriad Genetics, Inc.). Germline BRCA1/2 testing was performed in the North West Genomic Laboratory Hub using NGS and multiplex ligation-dependent probe amplification. Between 11 April 2021 and 11 October 2023, 382 patients were successfully tested for tumour BRCA1 and BRCA2 variants. Of these, 367 (96.1%) patients were tested for germline BRCA1/2 variants. In those patients who underwent tumour and germline testing, 15.3% (56/367) had a BRCA1/2 pathogenic variant (36 germline and 20 somatic). All germline BRCA1/2 pathogenic small sequencing variants were detected in tumour DNA. By contrast, 3 out of 8 germline BRCA1/2 pathogenic large rearrangements were not reported in tumour DNA. The overall concordance of germline BRCA1/2 pathogenic variants detected in germline and tumour DNA was clinically acceptable at 91.7% (33/36). The myChoice® CDx was able to detect most germline BRCA1/2 pathogenic variants in tumour DNA, although a proportion of pathogenic large rearrangements were not reported. If Myriad's myChoice® CDx is used for tumour BRCA1/2 testing, our data supports a testing strategy of germline and tumour BRCA1/2 testing in all patients diagnosed with epithelial ovarian cancer aged < 79 years old, with germline BRCA1/2 testing only necessary for patients aged ≥ 80 years old with a tumour BRCA1/2 pathogenic variant.