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GLP-1 medications have become one of the most talked-about medical breakthroughs in recent years. Best known for their ability to help people manage type 2 diabetes and lose weight, these medications are now being studied for potential benefits that extend well beyond weight management.
Cancer is one area surrounding GLP-1 medications generating particular interest. Researchers have long known that obesity and metabolic dysfunction are associated with an increased risk of several cancers. Now, emerging research suggests that GLP-1 medications may have effects on cancer risk and cancer outcomes that go beyond the weight loss they produce.
In order to better understand the connection between cancer and GLP-1 medications, Dr. Manish Shah, Director of Gastrointestinal Oncology and Chief of the Solid Tumor Program at Weill Cornell Medicine and Dr. Louis Aronne, Director of the Comprehensive Weight Control Center and the Sanford I. Weill Professor of Metabolic Research at Weill Cornell Medicine, explore what this class of drugs means for cancer care and prevention.
GLP-1, or glucagon-like peptide, is a naturally occurring hormone discovered in the early 1980s that plays a key role in satiety, feeling “full” after eating. “These medicines mimic naturally occurring hormones that are produced in the intestine and tell your brain how much you've eaten,” explains Dr. Aronne. When GLP-1 is present, it helps signal the brain that enough food has been consumed, reducing appetite and food intake.
Drugs like semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) are engineered to be far more potent and longer lasting than the natural hormones they mimic, which last only minutes in the body. Semaglutide acts primarily through the GLP-1 receptor, while tirzepatide acts on both the GLP-1 and GIP pathways. GIP, or glucose-dependent insulinotropic polypeptide, is also a naturally occurring hormone released by the intestine after eating.
These medications also affect insulin. GLP-1 receptor agonists stimulate the pancreas to release insulin, and the reduced food intake and weight loss can improve the body’s sensitivity to insulin. Dr. Shah helps frame the mechanism. “Essentially, these drugs make it easier for insulin to be used by the body,” he states. “These medications stimulate insulin release and the overall effect in the body is a reduction in the amount of insulin circulating in the blood because the body becomes more responsive to the insulin it does produce.”
The link between obesity and cancer has been recognized for decades. Obesity is associated with at least 13 different types of cancer, including breast, colon and rectum, endometrium, kidney, liver, pancreas, and gallbladder. “It's been pretty clear for probably thirty years that cancer and obesity overlap,” Dr. Aronne notes.
Fat cells, once believed to be inert storage, are now understood to produce dozens of hormones—including estrogen, insulin, and pro-inflammatory compounds like TNF-alpha—that can promote tumor growth, even if they don't directly cause cancer. When these hormones are present in excess, they can contribute to conditions associated with obesity, including chronic inflammation and metabolic dysfunction.
Dr. Shah points to inflammation as an important part of this cancer connection. “Inflammation is a common cause of many different conditions,” he says. “Chronic hepatitis raises liver cancer risk; inflammatory bowel disease raises colon cancer risk and obesity creates a similar chronic inflammatory state linked to elevated risk across multiple cancer types.”
Notably, where fat is stored matters. Visceral fat around the abdomen is metabolically active and strongly linked to inflammation and insulin resistance, while fat stored on the hips and thighs appears to be comparatively less harmful. This help explains why measures such as waist circumference can provide better information about metabolic health than simply body weight alone and the number on the scale.
Because it is already well established that obesity is associated with an increased risk of several cancers, it is reasonable to ask whether reducing obesity and improving metabolic health could impact cancer risk. Dr. Aronne points to emerging evidence suggesting that there may be a connection, even though more research is needed. “It looks like even without tremendous weight loss, there is benefit in giving people a GLP-1,” he shares. Researchers have identified receptors for GLP-1 in tissues throughout the body, suggesting a possible direct effect on pathways involved in tumor growth.
Research presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting supports this trend. A Penn Medicine study following more than 100,000 women with breast cancer found a roughly 30% reduction in breast cancer incidence among those taking a GLP-1 medication. Another study from the University of Texas San Antonio found a 33% reduction in acute myeloid leukemia, along with a significant reduction in chronic lymphocytic leukemia.
These findings do not yet mean that GLP-1 medications should be considered cancer-prevention drugs, but they provide important clues for researchers and raise additional questions to be evaluated in clinical trials.
“There are large observational cohorts that are now being reported that are comparing groups of people on a GLP-1 to those who were not. These data seem to show a reduction in the rate of developing certain cancers,” reinforces Dr. Shah.
Cancer prevention is only one part of the equation. Researchers are also asking questions regarding whether GLP-1 medications could also affect what happens after someone develops cancer. Studies are evaluating the impact GLP-1 medications have on cancer progression and recurrence. “We’re only really beginning to discover the full scope of how these medications work,” says Dr. Aronne.
The potential cancer connection is part of a much larger story surrounding GLP-1 medications. These drugs have demonstrated significant benefits for cardiovascular (heart) health and kidney function, in people with and without diabetes.
Additionally, as greater amounts of weight are lost with the support of these medications, metabolic health improvements can occur across multiple areas. For example, weight loss of approximately 15% or more can be associated with improvements across a broad range of obesity-related complications, including in other critical organs.
“For the first time, we've been able to delay the inevitable decline in kidney function that progresses to kidney failure,” notes Dr. Aronne. Similar outcomes are emerging for liver disease, known as steatosis, or fatty liver, which is one of the leading causes of needing a liver transplant in patients with obesity. These findings highlight that treating obesity may affect many interconnected aspects of health at the same time.
Together, these findings highlight that obesity has wide-ranging effects on the body, with negative effects across multiple organ systems and immune function. Importantly, having medications that can substantially reduce weight will have considerable benefits across all of these areas and we’re just now starting to witness these impacts.
GLP-1 medications are generally well tolerated, though gastrointestinal side effects like nausea, vomiting, and diarrhea are common. A more serious consideration is muscle loss, which can occur alongside significant weight loss, particularly without adequate protein intake. This is particularly important for older adults and people with cancer, as maintaining strength and muscle mass are an important part of overall health. Nutrition and resistance exercise are an important component of a comprehensive weight management plan.
Dr. Aronne also emphasizes that these benefits are not permanent without continued treatment. “When you take these medicines away, the effect goes away,” he explains, comparing it to stopping a cholesterol or blood pressure medication. This is one reason that obesity is increasingly now understood as a chronic disease that may require long-term management rather than a short-term problem that can be “fixed” through a temporary intervention.
There is a lot of excitement around this emerging research, and as we learn more information, more questions about how these medications can impact cancer and other conditions will emerge. Researchers aim to discover how GLP-1 drugs could be used alongside cancer treatments, who is most likely to benefit from these medications, whether these medications can reduce cancer recurrence, and more.
Dr. Aronne sees this as just the beginning. Ongoing research is exploring GLP-1 therapies for conditions ranging from sleep apnea to arthritis, and he anticipates cancer-specific indications may eventually follow, pending further clinical trials.
Dr. Shah summarizes the significance of this shift: “Obesity, particularly central obesity, is an inflammatory state that is associated with a higher risk of cancer. This is just the beginning, not the end of the story.” The broad impact of these medications on health and cancer are just beginning to be discovered.
Learn more about the intersection of obesity, metabolism, and cancer research on the CancerCast podcast where Drs. Shah and Aronne share insights into how these medications may open new doors for cancer prevention and care. Listen to the episode on Apple Podcasts, Spotify, YouTube, or the Weill Cornell Medicine website.
