Somatic BRCA Mutation in Metastatic Breast Cancer

A 65-year-old female with a history of multicentric invasive ductal breast carcinoma with lobular features and prior mastectomy presented with a chief complaint of two new raised mildly erythematous lesions on the right upper arm. The lesions were visualized during examination, and the patient noted no symptoms associated with them. Tangential shave biopsies were obtained for each lesion and were sent to the lab for testing. Both lesions were found to be metastatic breast carcinoma. Wide local excisions were performed on each site. The patient followed up with radiation therapy and was prescribed Faslodex and Ibrance. FoundationOne testing on the lesions revealed BRCA2 loss in the tumor, and germline DNA testing was performed in light of this. The test yielded negative results for harmful BRCA1 and 2 mutations. The patient was treated with Lynparza (olaparib), and two years following the start of this medication has had no additional recurrences.