Regular aspirin use does not improve invasive disease-free survival (iDFS) among high-risk breast cancer patients with human epidermal growth factor receptor 2 (HER2)-negative disease, according to a study presented Feb. 15 as part of the American Society for Clinical Oncology Plenary Series.
Wendy Y. Chen, M.D., M.P.H., from the Dana Farber Cancer Institute in Boston, and colleagues conducted a prospective randomized trial to compare the effect of 300 mg aspirin daily versus placebo on iDFS in patients with high-risk, HER2-negative breast cancer. A total of 3,021 patients were enrolled from January 2017 to December 2020.
The Data Safety and Monitoring Board recommended that the trial be unblinded in November 2021 because the stratified hazard ratio had crossed a prespecified futility boundary. After a median of 20 months of follow-up and 191 iDFS events (107 in the aspirin group; 84 in the placebo group), the stratified hazard ratio comparing aspirin with placebo was 1.27, which was greater than the prespecified hazard ratio for futility of 1.03. There was no difference observed between the groups in the frequency of grade 3/4 adverse events. Across arms, the nonprotocol use of aspirin/nonsteroidal anti-inflammatory drugs was similar and less than 14 percent.
"Although inflammation may still play a role in cancer progression, aspirin is not recommended for prevention of breast cancer recurrence," Chen said in a statement.
Several authors disclosed financial ties to biopharmaceutical companies, including Bayer.