Real-world homologous recombination repair mutation testing in metastatic castration-resistant prostate cancer in the USA, Europe and Japan.

Aim: To assess homologous recombination repair mutation (HRRm) testing patterns in metastatic castration-resistant prostate cancer. Methods: A point-in-time, international survey conducted January-August 2020. Results: Three-quarters of physicians (oncologists, urologists, specialist surgeons) globally reported access to genetic/genomic testing and just over half were HRRm testers. Surveyed physicians reported HRRm testing and positivity rates for 1913 patients, which were 18.1% and 33.7%, respectively. Of patients tested (n = 347), the most common HRR genes tested were BRCA (91.6%) and ATM (47.3%). Conclusion: Overall testing rates were low, with physicians mostly testing patients they considered higher risk. Increased awareness and education are needed to encourage broader testing, to understand familial risk and to identify patients with worse outcomes or those eligible for life-prolonging treatments.