The Efficacy of Platinum Chemotherapy in a Japanese Malignant Melanoma Patient With a BRCA2 Mutation Identified by Gene Panel Testing

A BRCA2 mutation increases the chance of developing cancer and has been linked to several diseases, including hereditary breast, ovarian, pancreatic, and prostate cancers. We present a case of advanced malignant melanoma treated with platinum-containing chemotherapy and demonstrate a momentarily favorable clinical outcome as determined by a Next Generation Sequencer (NGS) gene panel testing. A 54-year-old female with BRAF wild-type of anal primary melanoma received adjuvant immunotherapy with nivolumab following surgical resection. Novel distant lung metastasis was identified four months after the adjuvant therapy. Multi-gene panel testing figured out another potential treatment strategy using a sample from a distant metastatic tumor and identified a BRCA2 mutation in the tumor. Based on the sensitivity to platinum agents in BRCA2 mutation-positive tumors, DAC-Tam therapy (Dacarbazine, Nimustine, Cisplatin, and Tamoxifen) was administrated and showed tumor size reduction. After five rounds of DAC-Tam treatment, the metastatic lesion decreased from 17 mm to 5 mm. The parent was treated with platinum and Dacarbazine alone because of deteriorated renal function and grade 3 myelosuppression. In addition, the tumor showed resistance to the platinum plus Dacarbazine chemotherapy. Her chemotherapy-induced renal failure and bone marrow suppression did not improve well. Additionally, she felt significant weakness due to poor dietary intake and did not want to receive additional chemotherapy. To relieve her symptoms, she and her family desired the best supporting care and moved her to another hospital. The patient died 12 months after submitting the gene panel.