Prevalence of comprehensive DNA damage repair gene germline mutations in Chinese prostate cancer patients.

Germline DNA damage repair (DDR) deficiency has been associated with increased cancer risk, poor prognosis and therapeutic opportunity for prostate cancer (PCa) patients. However, the landscape of germline mutations in PCa covering comprehensive DDR genes has not been reported. We performed whole-exome sequencing in 246 patients who meet the National Cancer Center Network guidelines for genetic testing and analyzed variants in 276 DDR genes, which was from the Cancer Genome Atlas. A total of 79 deleterious germline alterations in 60 DDR genes were identified in 31% (76/246) patients. Mutations were found in nine DDR pathways, including 11.8% men in homologous recombination repair (HR) pathways, 2.4% men in mismatch repair (MMR) pathway and 16.7% (41/246) patients in non-HR/MMR pathways. In HRR and MMR pathways, mutations were mostly identified in BRCA2 (5.3%), HFM1 (0.8%), ZSWIM7 (0.8%), MSH2 (0.8%) and MSH3 (0.8%). When compared with the cancer-free cohort, POLN and POLG conferred high risk to PCa with odds ratio 6.9 and 20.5, respectively. We provided a comprehensive view of germline DDR gene mutations in PCa patients. We also identified two potential PCa predisposition genes: POLN and POLG, which have not been reported in the Western population, confirming the necessity of customizing a multigene panel for Chinese PCa patients.