Screening of BRCA2 mutated men for detection of prostate cancer: Preliminary results from a national high volume cancer center.

Abstract

e16567 Background: Up to 10% of cases of Prostate Cancer (PCa) are hereditary. Germline pathogenic mutations in BRCA2 gene confer the highest risk (2.5 to 8.6 fold in men ≤ 65 yr). Beyond periodic Prostate Specific Antigen (PSA) dosage and digital rectal examination (DRE), a targeted screening for carriers is still undefined. Prostate Health Index (PHI), a combination of the tPSA, fPSA and proPSA tests, may be a more accurate biomarker than PSA only to detect PCa. We evaluated how to better screen BRCA2 mutated men for PCa. Methods: We reviewed the genealogical trees of all women tested positive for germline BRCA2 pathogenic mutation at our clinic. We offered targeted BRCA2 mutational analysis to all first/second degree relative men between 40 and 69 yr. A targeted screening program (annual PSA and PHI dosages and DRE) was proposed to all men tested positive. In case of PSA and/or PHI values out of range ( > 4ng/ml and > 20, respectively) we proceeded with a multiparametric Magnetic Resonance Imaging (mpMRI) and fusion biopsy of suspected lesions. Results: From June 2008 to October 2018 610 breast/ovarian cancer patients had BRCA test: 35 (5.7%) tested positive for BRCA1 pathogenic mutation, 32 (5.2%) for BRCA2 pathogenic mutation. From October 2017 90 relatives were checked for the familial mutation and 24 (27%) (12 women, 12 men) tested positive for BRCA2 mutation. All the 12 men (median age 48 yr, IQR 44 to 60) accepted to join our screening program. During the first year all men had negative DRE. Median PSA was 0.70 (IQR 0.43 to 1.02), median PHI was 17.56 (IQR 11.85 to 24.06). One patient with out of range PHI value already had mpMRI resulted negative. During the second year 4 men underwent screening so far: they had negative DRE. Median PSA was 0.57 (IQR 0.38-0.77), median PHI was 16.88 (IQR 11.87-21.90). Two men had PHI out of range and will undergo mpMRI. Conclusions: An accurate review of the genealogical trees of breast/ovarian cancer BRCA2 mutated patients allows to identify male relatives potentially carriers of the same mutation. These men have a high lifetime risk of PCa and require an appropriate screening, currently absent. Our approach may be leveraged as proof of concept of selection and screening program in carriers of BRCA2 mutations.