Metastatic Breast Cancer with BRCA Mutation Discovered By Next-Generation Sequencing Responding to Olaparib.

Breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2) mutations are associated with hereditary breast and ovarian cancer syndromes (HBOC). However, certain individuals with breast cancer do not meet high-risk factors for hereditary breast cancer screening based on age, family history, and biology of malignancy. We present a patient with relapsed breast cancer who developed progressive disease with significant tumor burden causing a recurrent pleural effusion. Next-generation sequencing (NGS) done on a tumor biopsy was positive for the BRCA2 mutation. Olaparib was initiated with a resolution of the pleural effusion and a significant decrease in the size of the malignant lymphadenopathy and pulmonary lesions.  There are numerous reports of comprehensive molecular profiling improving access to therapy, most notably for lung cancer, as well as melanoma. However, this has not been widely utilized for breast cancer. However, in our case, NGS provided our patient with an effective therapy and should be considered for the future management of metastatic breast cancer.