New research tying GLP-1 medications to lower cancer risk is promising but not strong enough for people to take the drugs solely to prevent cancer, according to a University of Rochester Medicine cancer specialist.
Wilmot Cancer Institute medical director Dan Mulkerin said the findings may matter most for patients who already qualify for GLP-1 therapy because of diabetes or obesity, especially cancer survivors making treatment decisions with their health care team.
GLP-1 medications, sold under brand names including Ozempic, Wegovy and Zepbound, are used to regulate blood sugar in people with type 2 diabetes and to support weight loss. UR Medicine said the drugs have been shown over time to be safe and effective when used as prescribed.
The cancer question is drawing attention because obesity is linked to about 40% of cancer diagnoses in the U.S. UR Medicine said consistently high body fat has been associated with 14 types of cancer, with the highest risks for endometrial and esophageal cancer.
Mulkerin said GLP-1 medications should be considered as part of a broader care plan, not as a substitute for lifestyle changes. He said diet and exercise that support a lean body are already known to reduce the chance of relapse for people with cancer.
The current evidence connecting GLP-1 drugs to lower cancer risk comes from retrospective studies, which look back at medical records of people who were already taking the drugs for other reasons. Mulkerin said prospective clinical trials, which enroll patients and track outcomes in real time, remain the gold standard and are likely to follow because the early evidence is notable.
One study presented at the 2026 American Society of Clinical Oncology annual meeting examined records of more than 111,000 women ages 45 to 80 with a body mass index of 25 or higher. UR Medicine said researchers found women using GLP-1 medications were about 30% less likely to develop breast cancer.
A separate analysis of more than 841,000 patients with stage 1, 2 or 3 breast cancer found that women who had been taking GLP-1 drugs had a 60% lower death rate from any cause at five and 10 years after treatment compared with nonusers, according to UR Medicine.
Another ASCO study from Cleveland Clinic examined records of more than 12,000 people with diverse stage 1, 2 or 3 cancers. UR Medicine said people with obesity-related lung, breast, colorectal or liver cancer who were taking GLP-1 drugs for diabetes had a 38% to 50% lower risk of their cancer advancing to stage 4.
Mulkerin said Wilmot is not planning to prescribe GLP-1 medications to patients who do not otherwise take them for diabetes. But he said cancer patients who already meet criteria for the drugs may be able to work with oncologists and primary care physicians to consider potential cancer risk reduction as part of individualized care.
UR Medicine said large studies have not found that GLP-1 drugs cause cancer, though some questions remain under study. The medications carry a federal boxed warning tied to an early animal study involving medullary thyroid cancer, but UR Medicine said a 2025 Mayo Clinic analysis of human head-and-neck cancer cases found no link between GLP-1 drugs and thyroid cancer.
Mulkerin said severe side effects from GLP-1 drugs are rare and usually fade over time. He urged patients to evaluate risks and benefits with a physician and said anyone with persistent gastrointestinal pain should speak with a doctor.
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