A Novel BRCA2 Mutation in Prostate Cancer Sensitive to Combined Radiotherapy and Androgen Deprivation Therapy

Genetic factors contribute to more than 40% of prostate cancer risk, and mutations in BRCA1 and BRCA2 are well-established risk factors. By using target capture-based deep sequencing to identify potential pathogenic germline mutations, followed by Sanger sequencing to determine the loci of the mutations, we identified a novel pathogenic BRCA2 mutation caused by a cytosine-to-guanine base substitution at position 4211, resulting in protein truncation (p.Ser1404Ter), which was confirmed by immunohistochemistry. Analysis of peripheral blood also identified benign polymorphisms in BRCA2 (c.7397T>C, p.Val2466Ala) and SRD5A2 (c.87G>C, p.Lys29Asn). Analysis of tumor tissues revealed seven somatic mutations in prostate tumor tissue and nine somatic mutations in esophageal squamous carcinoma tissue (single nucleotide polymorphisms, insertions, and deletions). Five-year follow-up results indicate that ADT combined with radiotherapy successfully treated the prostate cancer. To our knowledge, we are the first to report the germline BRCA2 mutation c.4211C>G (p.Ser1404Ter) in prostate cancer. Combined ADT and radiotherapy may be effective in treating other patients with prostate cancer caused by this or similar mutations.