The Impact of Mutations of BRCA1 /2 Genes in Patients with Breast Cancer on Treatment Outcomes Following Radiation Therapy (RT)

In spite of pre-clinical data demonstrating increased radiosensitivity for BRCA1/2-mutated BC cells lines, this large, previously unexamined dataset found BRCA1/2 mutations did not predict an improved OS or DFS for patients who received RT. When compared with WT BRCA patients, patients with BRCA1/2 mutations were found to have tumors of higher grade and clinical stage and to undergo more mastectomies. In a comparison with BRCA2-mutated patients, patients with mutations of BRCA1 were younger, more often ER/PR negative, and more likely to have high-stage tumors. The survival data and the advanced stage of BRCA1/2-mutated tumors suggest that the effect of BRCA1/2 mutations on radiosensitivity in vitro may be nullified by the aggressive behavior of BRCA1/2-mutated tumors in vivo.