講演情報

[P26-12]Secondary findings using comprehensive genome profiling especially in metastatic castration-resistant prostate cancer

奥川 喜永1,2, 今井 裕1, 橋詰 令太郎1, 望木 郁代1, 中村 麻姫1, 池尻 誠1, 北嶋 貴仁1,2, 藤原 拓海1, 中谷 中1 (1.三重大学・ゲノム診療科, 2.三重大学大学院・消化管・小児外科学)
Background. Olaparib was approved in patients with metastatic castration-resistant prostate cancer(mCRPC) harboring BRCA1/2 alteration by Japanese insurance, and comprehensive genomic profiling(CGP) is extremely expanded. However, previous studies showed that half of the BRCA1/2 alteration in mCRPC was originated from germline variants, and its frequency remains unclear in Japan.Methods. We evaluated 504 patients received insurance-approved CGP using FoundationOne CDx, FoundationOne Liquid CDx, or NCC Oncoguide in our institute. Results. Patients received FoundationOne CDx(n=349), FoundationOne Liquid CDx (n=88), and NCC Oncoguide (n=67), respectively. Thirty patients didn’t want to know the results of secondary findings, and 4 patients deceased before explaining the results. From 487 patients, 27 patients got genetic counseling(GC), and 12 patients finally confirmed germline pathogenic variants(APC, MLH1, BRCA1/2, RB1, TP53, NF1). Especially in mCRPC, 54 patients received CGP tests, and they received FoundationOne CDx(n=27) or FoundationOne Liquid CDx(n=27). Eleven patients detected BRCA1/2 pathogenic variants, and 6 patients disclosed presumed pathogenic germline variants of BRCA1/2. Five patients presented to GC and all patients received genetic test. Finally, 4 patients(7.4%) confirmed germline BRCA2 variants, and one first-degree relative confirmed germline pathogenic variants.Conclusion. Japanese mCRPC patients also included population carrying BRCA1/2 germline mutations with relatively high rate, and need to provide clinical approach for hereditary cancer.