As glucagon-like peptide-1 receptor agonists continue to reshape the treatment of obesity and diabetes, researchers are actively investigating whether medications like Ozempic, Wegovy, Mounjaro, and Zepbound influence cancer risks and patient outcomes. The American Association for Cancer Research (AACR) released its 2026 Cancer Progress Report earlier this month, emphasizing that while obesity remains a major, established risk factor for many malignancies, the clinical evidence connecting GLP-1 therapies directly to cancer prevention remains mixed.
GLP-1 Weight-Loss Drugs and Cancer Risk: What the American Association for Cancer Research Reports
The AACR report underscores that randomized clinical trials—the scientific gold standard—have not yet been specifically conducted to evaluate cancer outcomes associated with GLP-1 receptor agonist use. Although observational studies point toward potential protective associations, medical experts stress the need for continued, rigorous investigation before definitive conclusions can be drawn.
Evaluating the Link Between Obesity and Cancer Progression
Obesity stands as a leading cause of cancer, second only to smoking, according to Sai Yendamuri, M.D., a thoracic surgeon at Roswell Park Comprehensive Cancer Center in Buffalo, New York. Additional lifestyle risk factors, including alcohol consumption and poor nutrition, are frequently intertwined with obesity. Because excess body weight drives both the onset and progression of specific cancers, researchers have naturally questioned whether pharmacologic treatments for obesity could alter that trajectory.
“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 said in an interview with Fox News Digital.
Data from metabolic surgeries designed to treat obesity show a decreased incidence of cancer among patients who underwent the procedures. That precedent prompted investigators to evaluate patients prescribed GLP-1 receptor agonists. According to Yendamuri, many retrospective studies comparing GLP-1 users to non-users found a lower incidence of cancer and higher survival rates among those taking the medications.
Understanding Retrospective Studies and Conflicting Findings
While the majority of published retrospective analyses demonstrate favorable associations, some investigations identified no clear relationship, and a small number of studies pointed toward an increased risk of specific malignancies, such as thyroid cancer. Experts attribute these conflicting signals to the inherent limitations of retrospective study designs.
“The reason you find this disconnect … is because these are retrospective studies,” Yendamuri explained, noting that researchers attempt to derive associations from existing data where numerous confounding variables can impact final results.
In specialized research focusing on thoracic malignancies, Yendamuri and his team have consistently found that obesity increases the risk of lung cancer. Many obesity researchers are shifting away from traditional body mass index (BMI) metrics toward more precise assessments of body fat composition to better understand these physiological risks.
Immune Response and Post-Surgical Recurrence
Recent surgical and oncological observations offer fresh insights into how GLP-1 medications might interact with cancer therapies. Data from Yendamuri’s research indicate that lung cancer patients undergoing surgical resection who are concurrently taking GLP-1 receptor agonists experience lower recurrence rates. Similarly, advanced-stage cancer patients undergoing immunotherapy while taking GLP-1 medications demonstrate lower recurrence rates.
Preclinical laboratory evaluations suggest that these medications have only a limited direct effect on cancer cells. Instead, researchers hypothesize an indirect mechanism involving the immune system. “What we think is happening is that it changes the body’s immune response to cancer cells, and thereby improves its ability to fight cancer cells,” Yendamuri stated.