GLP-1 Drugs' Potential Role in Cancer Outcomes Under Investigation

Researchers are investigating a potential link between glucagon-like peptide-1 (GLP-1) medications, widely used for obesity and diabetes, and their impact on cancer risk and outcomes. The American Association for Cancer Research's (AACR) 2026 Cancer Progress Report highlights obesity as a significant risk factor for numerous cancers, prompting closer examination of these drugs.

GLP-1 receptor agonists, including semaglutides like Ozempic and Wegovy, and tirzepatides such as Mounjaro and Zepbound, are known for promoting substantial weight loss and improving metabolic health. This has drawn considerable attention from cancer researchers.

While the AACR report notes some studies suggest GLP-1 medications might reduce the risk of certain cancers, it emphasizes that the evidence is mixed and requires further rigorous investigation. The report states that randomized clinical trials specifically designed to assess cancer outcomes related to GLP-1 receptor agonist use have not yet been conducted.

Dr. Sai Yendamuri, a thoracic surgeon at Roswell Park Comprehensive Cancer Center, pointed out that obesity is a leading cause of cancer, second only to smoking. He also cited alcohol consumption and poor nutrition as contributing factors, all of which are often associated with obesity. "So if obesity is related to cancer – both in terms of causing it and increasing its progression – the logical question is, would a drug that decreases obesity have an impact?" Yendamuri commented.

He further suggested that evidence from studies on patients undergoing metabolic surgery to reduce obesity, which showed a decrease in cancer incidence, supports this line of inquiry. Researchers have also examined patients taking GLP-1 receptor agonists and compared their cancer incidence to those not on the drugs. Many of these retrospective studies have indicated lower cancer risk and higher survival rates in patients using GLP-1s.

However, Yendamuri acknowledged that not all studies have found a relationship, and a few have even suggested an increased risk for specific cancers, such as thyroid cancer. He attributed these discrepancies to the nature of retrospective studies, which rely on existing data and can be influenced by numerous variables.

Research conducted by Yendamuri and his team has focused on the relationship between obesity and lung cancer. They noted that the definition and measurement of obesity can vary, with a shift away from relying solely on Body Mass Index (BMI) towards more precise assessments of body fat composition.

Two key findings from Yendamuri's research suggest that patients undergoing lung cancer surgery who are on GLP-1 receptor agonists appear to have a lower recurrence rate. Additionally, patients with advanced-stage cancers receiving immunotherapy and taking GLP-1s also showed lower recurrence rates.

Based on preclinical laboratory studies, Yendamuri theorizes that GLP-1 medications may have a limited direct effect on cancer cells. Instead, he believes they might alter the body's immune response to cancer, thereby enhancing its ability to combat the disease. The impact could vary depending on the cancer type, as immune response plays a more critical role in certain cancers, such as melanoma.

Yendamuri also conceded that some of the observed cancer benefits likely stem from the weight loss associated with these drugs. Future trials could explore whether the benefits are dependent on the degree of weight loss achieved by patients.

Looking ahead, Yendamuri expressed hope that GLP-1 drugs could eventually be considered a preventive measure for cancer, alongside other lifestyle modifications like exercise and weight management. He stressed the ongoing need for funding for cancer research to develop new discoveries and advance treatment options.