Response to olaparib in metastatic lung adenocarcinoma with germline BRCA2 mutation: a case report

Mutation of BRCA2, a breast cancer susceptibility gene, is associated with the development of breast and ovarian cancer. Olaparib is an oral poly-adenosine diphosphate-ribose polymerase (PARP) inhibitor, which has been proven to treat BRCA-mutated tumors effectively, especially breast and ovarian cancer. Here, we report a case of a germline BRCA2-mutated metastatic lung adenocarcinoma, non-small-cell lung cancer, responded well to olaparib. A 41-year-old man with no history of smoking was diagnosed with advanced lung adenocarcinoma. The patient was treated with bevacizumab, pemetrexed disodium, and cis-platinum in the first-line therapy of 6 months, followed by bevacizumab, Abraxane, and sintilimab treatments for another 6 months. As disease progression was confirmed and the presence of germline BRCA2 mutation, the combinational treatment of olaparib/anlotinib was applied to achieve partial response 1 month later, and the progression-free survival was extended for another 5 months. This study shows metastatic lung adenocarcinoma with BRCA2 mutation could also respond well to PARP inhibitor, broadening the spectrum of BRCA-mutated cancers suitable for olaparib therapy. With acquired resistance to chemotherapy, bevacizumab, and immunotherapy, the patient still gained significant benefits from the targeted therapy.