Once viewed primarily as weight loss and diabetes drugs, GLP-1 medications are drawing increased scrutiny in oncology. Leaders are beginning to examine what the drugs could mean for cancer risk and outcomes, as a growing body of research suggests the effects may be more nuanced — and in some cases more promising — than initially expected.
A study from researchers at Cambridge, Mass.-based Harvard University found that GLP-1 drugs such as Ozempic and Zepbound had “little or no effect” on an individual’s risk of developing thyroid, breast, pancreatic or kidney cancer.
According to research presented at the 2026 American Society of Clinical Oncology’s Gastrointestinal Cancers Symposium, GLP-1 drugs were associated with about 5.6 fewer deaths per 100 patients with colorectal cancer and obesity compared to those who did not take a GLP-1 over a 10-year period.
Patients with endometrial hyperplasia or benign uterine pathology had a 66% reduced risk of developing endometrial cancer when treated with progestins and a GLP-1 compared to patients treated with progestins alone, according to a study published Feb. 10 in JAMA Network Open.
Becker’s asked 14 leaders in oncology if GLP-1s have real potential to change the cancer landscape.
Editor’s note: Responses have been lightly edited for clarity and length.
Frantz Berthaud. Senior Vice President of Oncology Services at University Medical Center of El Paso (Texas): The short answer is yes and no. They show real — though early — and growing evidence of reducing risk specifically as we look at obesity-related cancers, but it’s all still emerging. Less hype but certainly hope. Right now, we’re a bit ahead of the data when it comes to definitive prevention claims or promises of improving cancer treatment outcomes. There is such a focus on metabolic oncology now more than ever so looking at GLP-1 as a supplemental tool in the arsenal against cancer is a viable thing.
Peter Blumencranz, MD. Surgical Oncology, Medical Director BayCare Cancer Institute (Clearwater, Fla.): We know that obesity is linked to at least 13 types of cancer. Recent studies suggest that GLP-1 users have a lower risk of colorectal cancer and may have lower mortality if they develop colon cancer. How these drugs work is the question. Weight loss alone is a big factor and the most benefit has been seen in the morbidly obese with BMI greater than 35. Obesity leads to inflammatory response in the body, and reduced inflammation as a consequence of taking these drug drugs may be a mechanism for how they work.
Whether there is a direct anti-tumor growth effect needs further study. The data so far comes from observational studies, not randomized control trials, which provide the best evidence as to whether the observed reductions in incidence and mortality are truly due to these drugs or some other cause. Nevertheless this is exciting and provides a stimulus for further investigation.
Monica Cfarku, MSN, RN. Senior Director of the Oncology Service Line at Inova Health System (Fairfax, Va.): As a nursing leader, I view the emerging data on GLP‑1 medications with both optimism and caution. I see real potential in the way these therapies may improve patients’ metabolic health, which is an important factor in cancer prevention and treatment tolerance. At the same time, I recognize that the excitement around GLP‑1s can outpace the evidence. From my perspective, these medications are promising, but they should complement — not replace — a comprehensive, patient‑centered cancer care strategy. I believe our role is to stay curious, grounded in the science and focused on the whole patient as this area continues to evolve.
Raymond DuBois, MD, PhD. Director of MUSC Hollings Cancer Center (Charleston, S.C.): This is a very interesting study demonstrating a significant reduction in five-year mortality among patients with colorectal cancer who used GLP-1 receptor agonists. Importantly, the benefit persisted even after adjusting for disease severity and other relevant clinical factors.
At present, at least nine cancers are known to have an increased risk in individuals with obesity. Obesity contributes to cancer risk through multiple mechanisms, including chronic low-grade inflammation, altered IGF-1 signaling, increased estrogen production, dysregulated adipokine signaling, immune dysfunction and changes in the tumor microenvironment. In this context, it is biologically plausible that weight loss associated with GLP-1 receptor agonist therapy could confer meaningful benefits.
However, additional work is needed. Large, longitudinal studies with longer follow-up will be essential to determine whether these findings persist across broader populations and over extended periods. Given that GLP-1 receptor agonists also have known adverse effects, larger and longer-term studies will be important to better define the balance of risks and benefits associated with their use in patients at high risk for cancer.
Arturo Loaiza-Bonilla, MD. System Chief of Hematology and Oncology at St. Luke’s University Health Network (Bethlehem, Pa.): We’re seeing a real signal that GLP-1s may influence cancer biology, particularly in obesity-driven and hormone-sensitive cancers. The recent endometrial data showing a roughly two-thirds risk reduction with GLP-1 plus progestin therapy is compelling.
But we have to be careful. These are observational findings, not definitive cancer prevention trials. GLP-1s aren’t “cancer drugs,” yet they may be powerful metabolic modifiers that shift long-term cancer risk.
The hype isn’t entirely overblown, but the next step must be prospective trials to prove causality.
Cory Jones. Associate Vice President of Oncology Services for Banner Health (Phoenix): As GLP-1s gain wider acceptance, healthcare teams must foster evolving multidisciplinary conversations that manage expectations and guide our understanding of potential cancer outcome impact.
Matthew Manning, MD. Radiation Oncologist at Cone Health (Greensboro, N.C): The emerging data on GLP-1s and cancer outcomes are intriguing, particularly in obesity-related cancers like colorectal cancer. However, whether we are seeing correlation, not proof of causation. Many of the benefits may stem from weight loss and metabolic improvement rather than a direct anticancer effect. The potential is exciting, and we will need prospective data before declaring GLP-1s a cancer breakthrough.
Ruben Mesa, MD. President of the Cancer National Service Line and Senior Vice President at Advocate Health (Charlotte, N.C.) and Executive Director of Atrium Health Wake Forest Baptist Comprehensive Cancer Center (Winston-Salem, N.C.): GLP-1s are an important area of research, particularly for their potential impact on cancers that are driven in part by metabolic syndrome. Recent real-world evidence suggesting a reduction in colon cancer mortality is especially intriguing. That said, there are important confounders to consider as the data and prospective studies continue to mature, including differences in access to care, overall healthcare quality, and social determinants of health among early adopters of these medications. Additionally, the long latency period typically required for colon cancer to develop must be taken into account. While the findings are promising and warrant further study, it is likely premature to prescribe these medications outside of their approved indications. However, studies exploring this approach in higher-risk populations are clearly justified.
John Montville. Executive Director of the Oncology Service Line for the Paducah (Ky.) Cancer Center at Mercy Health-Lourdes Hospital: Anytime we see anything that will reduce cancer risk, we get very excited. As this continues to be studied, it is hopeful that we can unlock exactly why it is reducing cancer risk, which can translate into both prevention and, potentially, new treatments based on the technology. At a time we are seeing a marked increase in colorectal cancer, especially in younger patients, it is good to see something that might lower incidence rates for this cancer.
Yinka Ojutalayo, PharmD. Director of Pharmacy and Infusion Services at Dana-Farber Cancer Institute (Boston): Based on observational studies, GLP-1s show a real potential to reduce cancer risk and improve outcomes. Theoretically, their effects on metabolic and inflammatory pathways could meaningfully influence cancer progression. However, randomized controlled trials are still needed to confirm whether these associations translate into a true shift in the cancer care landscape.
Adedayo Onitilo, MD. Director of Cancer Care and Research at Marshfield (Wis.) Clinic: In my opinion, weight loss, not GLP-1 therapy, is what modulates cancer risk. So long as we get the weight down, we decrease cancer risk, be it GLP-1, bariatric surgery or lifestyle.
You may ask, “How does weight loss reduce cancer risk?”
Weight loss reduces cancer risk because excess body fat actively alters the body’s biology in ways that can promote tumor development. Fat tissue produces inflammatory chemicals that can damage DNA, raise insulin and IGF-1 levels that stimulate cell growth, and, especially after menopause, increase estrogen production, which is linked to breast and endometrial cancers. Obesity can also impair immune surveillance, making it harder for the body to eliminate abnormal cells. By reducing inflammation, normalizing hormone and insulin levels, and improving immune function, weight loss lowers several biological drivers that increase the risk of cancers such as colorectal, breast (postmenopausal), endometrial, pancreatic, liver, and kidney cancer.
Melody Schiaffino, PhD. Associate Professor in the Department of Radiation Medicine and Applied Sciences at University of California San Diego: Obesity is a known risk factor for multiple cancers. These are promising preliminary studies that demonstrate benefit, but it is still unclear if the benefit is directly related to the use of GLP-1 or indirectly, due to reduction in obesity.
Cardinale Smith, MD, PhD. Chief Medical Officer at Memorial Sloan Kettering Cancer Center (New York City): The data and in particular, this colon cancer survival analysis is intriguing, especially the stronger association in patients with BMI over 35. However, it’s still observational and vulnerable to time-related bias. While real-world designs are starting to show modest risk reductions in some cancers, at the moment this is hypothesis-generating, not practice-changing.
Darren Tishler, MD. Chief of Metabolic and Bariatric Surgery at Hartford (Conn.) HealthCare: It is well known that obesity increases the risk of certain types of cancers and can decrease cancer survival risk. This has been shown especially for endometrial, esophageal, post-menopausal breast, and kidney cancer. It has also been shown that bariatric surgery, in addition to effectively reducing weight, can also reduce the risk of many cancers. Obesity is a disease of inflammation and, through complex pathways, this inflammation is probably one of the links to increased cancer risk in obesity. It would be safe to say that any significant and durable weight reduction, including that from GLP1 receptor agonists, will also reduce the risk of some types of cancer and possibly improve survival. However, there have not to date been any large scale longitudinal prospective randomized trials to determine whether GLP1-receptor agonist drugs have a direct anti-cancer effect or if any cancer risk reduction is due to the weight loss itself. I think it is safe to say, however, that weight reduction, whether from a GLP1-receptor agonist or bariatric surgery, promotes health, well-being, and improves overall longevity and quality of life for many individuals.
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