Inherited germline mutations in men with prostate cancer.

Abstract

e16564 Background: Recent studies have demonstrated a high prevalence of pathogenic variants (PVs) in genes that confer hereditary cancer risk among men with metastatic prostate cancer (PC); however, PC does not currently receive attention as an indication for genetic testing. We assessed the clinical features of men with PC who received clinical testing as well as the distribution of PVs identified. Methods: A commercial laboratory database was queried to identify men with PC who underwent testing with a multi-gene hereditary cancer panel from September 2013–September 2016. Clinical information was obtained from provider-completed test request forms. Individuals with PC only were evaluated separately from those who had ≥1 additional malignancy. Personal/family history was evaluated relative to the 2013 NCCN guidelines for hereditary breast and ovarian cancer (HBOC) testing. Results: Overall, 700 men with a personal history of PC were identified: 384 (54.9%) with only PC and 316 (45.1%) with PC and ≥1 additional malignancy. The most common additional malignancies were colorectal (115) and breast cancer (105). The median age of diagnosis in men with only PC was 57.5, which is younger than tested men who had an additional malignancy (62) and the SEER data (2009-2013) for all men with PC (66). HBOC testing criteria were met by 75.9% of men, including 44 (6.3%) who met based only on a personal/family history of PC and 202 (28.9%) who met in part due to a personal/family history of PC. PVs were identified in 14.0% of all men: 11.5% of men with PC only and 17.1% of men with PC and a second malignancy (see Table). Conclusions: PC patients selected for genetic testing here were younger than men diagnosed with PC from the general population (SEER), and almost half had a diagnosis of an additional malignancy. They also have a high positive mutation rate across a broad spectrum of genes. [Table: see text]