Adjuvant Olaparib for Germline BRCA Carriers With HER2-Negative Early Breast Cancer: Evidence and Controversies

In the OlympiA study, 1 year of adjuvant olaparib significantly extended invasive disease-free survival and overall survival. The benefit was consistent across subgroups, and this regimen is now recommended after chemotherapy for germline BRCA1/2 mutation (gBRCA1/2m) carriers with high-risk, HER2-negative early breast cancer. However, the integration of olaparib in the landscape of agents currently available in the post(neo)adjuvant setting - ie, pembrolizumab, abemaciclib, and capecitabine - is challenging, as there are no data suggesting how to select, sequence, and/or combine these therapeutic approaches. Furthermore, it is unclear how to best identify additional patients who could benefit from adjuvant olaparib beyond the original OlympiA criteria. Since it is unlikely that new clinical trials will answer these questions, recommendations for clinical practice can be made through indirect evidence. In this article, we review available data that could help guide treatment decisions for gBRCA1/2m carriers with high-risk, early-stage breast cancer.