🔎︎
Denise Yardley, MD, GCRA, Associate Director of Breast Cancer Research at Sarah Cannon Research Institute (SCRI), explained the recent observational data presented at ASCO 2026 showing breast cancer patients on GLP-1s may progress to metastatic disease at about half the rate of those on older diabetes drugs. Dr. Yardley emphasized that while the retrospective data are promising, significant limitations exist, including a lack of prospective randomized trials, uncertainty about the benefits for patients with normal BMI, and potential contraindications with other cancer treatments. She discussed the challenges of managing patient expectations and noted that insurance coverage remains uneven, often excluding indications related to cancer. Dr. Yardley expressed cautious optimism about future prospective trials, particularly those exploring circulating tumor DNA detection, while warning that more data is needed before recommending GLP-1s for breast cancer risk reduction outside of established medical indications.
About the study: A propensity-matched real-world analysis of 12,000-plus patients found that GLP-1 users had a 38-50% lower risk of progressing to stage 4 breast, colorectal, and liver cancers than with older diabetes drugs (for breast cancer, roughly 10% progression vs 20%). A separate analysis tied adding a GLP-1 to endocrine therapy plus a CDK4/6 inhibitor to a 30% lower mortality risk in HR+/HER2- metastatic breast cancer. High tumor GLP-1 receptor expression correlated with 33 percent lower mortality overall, and about 45 percent in breast cancer. All of it observational, with the investigators themselves calling for randomized trials.
Dr. Yardley, a principal investigator on major breast cancer trials including NATALEE, APHINITY, and the RIBBON studies, was not the lead author on this study.
