Population Estimates of Ovarian Cancer Risk in a Cohort of Patients with Bladder Cancer.

ABSTRACT

BACKGROUND AND OBJECTIVE: The rationale for oophorectomy during female cystectomy is not adequately supported. The co-occurrence and timing of bladder cancer (BC) and ovarian cancer (OC) in females harboring OC germline mutations remain unclear. Our objective was to determine the frequency and temporal occurrence of OC germline variants among females with BC. METHODS: We used genetic and phenotypic data from the UK Biobank (UKB). The study cohort was defined using ICD-10/ICD-9 codes for BC and further stratified to identify 1347 females. Analysis was restricted to variants with high/moderate impact for initial regression. ClinVar was used to interpret pathogenicity. Pathogenic/likely pathogenic (P/LP) variants were assessed by age of presentation, family history, and concomitant malignancies. Statistical analysis was performed using UKB DNAnexus JupyterLab and RStudio. KEY FINDINGS AND LIMITATIONS: Some 3.4% of the patients had at least one of 15 variants for OC. CHEK2 and PALB2 mutations represented the highest ratio of overall/pathogenic variants (15.8% and 6.6%). Although females with P/LP OC mutations had a higher risk of OC, diagnosis of OC preceded BC by 11.3 yr (±12.5 yr) in the group with mutations and by 15.6 yr (±11.3 yr) in the group without mutations. The group with P/LP variants had higher rates of maternal (14.63% vs 8.12%; p = 0.04) and sibling (9.76% vs 3.98%; p = 0.02) breast cancer and of maternal colon cancer (9.76% vs 4.21%), and lower maternal life expectancy (75.34 vs 68.15 yr; p = 0.0014). UKB provides limited staging/treatment history and its exome sequencing platform may miss variants or provide insufficient coverage for genotyping. CONCLUSIONS AND CLINICAL IMPLICATIONS This study provides evidence against routine oophorectomy for reducing OC risk in females with BC. The results highlight that the development of OC occurred 11 yr before diagnosis of BC for patients with OC mutations and 15 yr before diagnosis of BC for patients without OC mutations. PATIENT SUMMARY: Although removal of the ovaries in women with bladder cancer is common, no studies have shown that this strategy has a benefit. Our study of women diagnosed with bladder cancer who had genetic mutations associated with ovarian cancer shows that their risk of developing ovarian cancer after bladder cancer is low. These findings provide evidence against removal of the ovaries when the bladder is being removed as treatment for bladder cancer.