2022 Volume 21 Issue 3 Pages 85-88
The acquisition of reversion mutations is currently attracting attention as a key resistance mechanism to PARP inhibitors in BRCA-mutant cancer. We report a case of BRCA2 mutation-positive metastatic breast cancer tolerance to PARP inhibitors after long-term remission maintained with platinum-based chemotherapy. A 53-year-old woman diagnosed with triple negative breast cancer (cT1cN0M0 stage I) underwent surgery. Local recurrence was observed 4 years and 10 months postoperatively, followed by a relapse of the axillary, pulmonary, and chest wall metastases. Suspecting hereditary breast cancer ovarian cancer syndrome (HBOC), she was successfully treated with carboplatin-based chemotherapy, and had remained in remission for 5 years and 4 months. However, liver and bone metastases appeared 11 years and 7 months after surgery. At this point, national health insurance started to cover the BRCA test as a companion diagnosis for Olaparib in Japan, and she was positive for a BRCA2 mutation. Then, Olaparib was initiated, however, she subsequently died with little therapeutic effect.
