NEW YORK – The American Society of Clinical Oncology on Tuesday issued an updated guideline recommending one year of adjuvant treatment with the PARP inhibitor olaparib (AstraZeneca/Merck's Lynparza) for patients with high-risk, early-stage, HER2-negative breast cancer harboring germline BRCA1 or BRCA2 mutations.
The society's recommendation is based on the results of the Phase III OlympiA trial, in which breast cancer patients with BRCA1/2 mutations on adjuvant olaparib had significantly improved invasive disease-free survival rates compared to those on placebo. After three years of follow-up, 86.9 percent of patients on olaparib were free of invasive disease, versus 77.1 percent of patients on placebo. The results were recently published in the New England Journal of Medicine and presented during ASCO's virtual annual meeting.
The data sparked conversations at the meeting about potential updates to treatment guidelines recommending olaparib in the adjuvant breast cancer setting, but also to genetic testing criteria to determine patients' germline BRCA1/2 mutation status.
The society now recommends that doctors offer olaparib to patients after they have completed neoadjuvant or adjuvant chemotherapy and local treatment, including radiation. Patients who have had surgery must have triple-negative breast cancer tumors larger than two centimeters or have involved axillary nodes to receive adjuvant olaparib. Additionally, HER2-negative, hormone receptor-positive breast cancer patients with residual disease and an estrogen receptor status and tumor grade, or CSP+EG, score of at least three can also receive the treatment.
The latest guidelines replace a previous recommendation jointly issued by ASCO, the American Society for Radiation Oncology, and the Society of Surgical Oncology, which said that there were insufficient data to recommend PARP inhibitors to patients with non-metastatic BRCA1/2-mutated breast cancer.
ASCO's recommendation still needs to undergo formal assessment and publication in the Journal of Clinical Oncology. However, the society opted to issue it provisionally first so that eligible patients could begin to benefit from the treatment immediately.
"Guideline updates have traditionally required months to review new data, assemble an expert panel, develop, approve, and publish recommendations — making it difficult to provide timely support to clinicians seeking to keep abreast of rapidly advancing research," ASCO CEO Clifford Hudis said in a statement. "ASCO's new rapid guideline updating strategy is meant to address this need by providing rapid evidence review and dissemination of practice-changing trial results."