Three new observational studies presented at the American Society of Clinical Oncology (ASCO) meeting in Chicago suggest GLP-1 medications, including Ozempic and Wegovy, may significantly reduce the risk of breast cancer and improve outcomes for patients.
The first study, led by Dr. Elizabeth McDonald of the University of Pennsylvania, analyzed data from over 110,000 women aged 45 to 80. It found that women who had taken GLP-1 drugs were 30.5% less likely to be diagnosed with breast cancer, even after accounting for factors like age, BMI, and diabetes status.
A second study examined more than 12,000 cancer patients and found those on GLP-1 drugs had half the risk of cancer progression compared to those on other diabetes medications. For breast cancer specifically, progression occurred in 10% of GLP-1 users versus 20% of non-users.
The third study tracked 137,493 breast cancer patients and found a 6% higher five-year survival rate among those who took GLP-1 drugs for at least three continuous months.
Researchers emphasize these are observational findings and do not prove causation. However, the consistency across multiple tumor types has prompted calls for prospective randomized trials. GLP-1 drugs are known to reduce inflammation and modulate immune function, which may explain the broader protective effects beyond weight loss.