Metastatic lung adenocarcinoma with BRCA2 mutation and longstanding disease control on olaparib, developing triple negative breast adenocarcinoma with additional BRCA2 reversion mutation: A case report

The BRCA2 gene is a well-known tumor suppressor gene implicated in breast and ovarian cancers. BRCA1/2 mutations can be sensitive to poly ADP-ribose polymerase (PARP) inhibitors such as olaparib. However, some of these patients develop resistance to this treatment and an essential factor contributing to acquired insensitivity is the occurrence of reversion mutations in the BRCA1/2 genes.