BRCA2 reversion mutation confers resistance to olaparib in breast cancer.

ABSTRACT

Key Clinical Message A rare missense mutation was identified as a reversion mutation using cancer genomic profiling and a suspected mechanism underlying resistance to olaparib in breast cancer. Abstract A 34-year-old woman with breast cancer and BRCA2 p.Gln3047Ter was treated with olaparib. After tumor progression, cancer genomic profiling testing using liquid biopsy revealed BRCA2 p.Gln3047Ter and p.Gln3047Tyr, with 48.9% and 0.37% allele frequency, respectively. These findings shed light on reversion mutation as a mechanism of resistance to olaparib in breast cancer.