Medications like Ozempic, Wegovy, and Zepbound, originally designed to treat obesity and diabetes, are now sparking excitement among researchers for their potential in addressing other health conditions, including addiction, sleep apnea, and even cancer.
These drugs belong to a class known as GLP-1 agonists, which are gaining attention for their ability to influence brain activity, regulate hormones, slow digestion, and reduce hunger. Recent studies have begun to reveal their potential in preventing common cancers such as breast, colon, liver, and ovarian cancers, all of which are often linked to obesity.
“It’s a hopeful story, which is, frankly, what people need,” said Arif Kamal, an oncologist specializing in breast cancer and chief patient officer at the American Cancer Society.
Though the research on GLP-1 drugs is still in the early stages, studies consistently indicate their effectiveness in reducing the risk of certain cancers. A letter published in JAMA Oncology last year, for example, suggested that GLP-1 drugs might lower the risk of colon cancer, even in individuals who are not overweight. A more recent analysis in JAMA Network Open found that these drugs offer greater protection against cancer for diabetic patients compared to insulin treatments.
At the American Society of Clinical Oncologists meeting in June, a study revealed that both bariatric surgery and GLP-1 medications significantly lower the risk of the 13 cancers associated with obesity. Patients who underwent bariatric surgery saw a 22% reduction in risk over ten years compared to those who received no treatment. Remarkably, those on GLP-1 medications experienced a 39% reduction in risk.
“A 39% risk reduction is one of the most impactful we’ve ever seen,” Kamal noted.
GLP-1 agonists were initially developed for diabetes treatment nearly two decades ago. Over the last decade, they have also been approved for weight loss, starting with liraglutide, marketed as Saxenda, and more recently with semaglutide or tirzepatide, under brands like Wegovy and Zepbound.
The connection between obesity and cancer is complex, with obesity-related cancers often affecting organs involved in digestion and metabolism, such as the liver and pancreas, as well as reproductive organs like the breast and uterus. These organs are particularly sensitive to estrogen, a hormone that promotes rapid cell growth during pregnancy.
Kamal highlighted the strong link between estrogen and cancer. “What we do know is that estrogen, and possibly some other hormones, drives the growth of many cancers,” he explained. Since fat cells increase estrogen production, the risk of cancer rises with higher body fat levels.
Women are becoming increasingly susceptible to cancer, closing the gender gap that once existed due to higher-risk behaviors like smoking and drinking, which were more common among men. Kamal pointed out that obesity might now be the most significant factor behind the rising cancer rates among younger adults, much like tobacco was for previous generations.
“Unhealthy weight is the smoking of our generation,” Kamal stated, emphasizing the importance of GLP-1 drugs in potentially reducing this risk.
The study presented at ASCO also suggested that GLP-1 drugs might lower cancer risk even when patients do not lose significant weight. This implies that these medications may influence several mechanisms within the body to reduce cancer vulnerability.
“We think the protective effects of GLP-1s are probably multifactorial,” said Cindy Lin, resident physician at Case Western Reserve and co-author of the ASCO study. “Part of it is weight loss, but other factors may be contributing as well, such as better glycemic control and anti-inflammatory effects.”
Further research is needed, especially on the newer GLP-1 medications formulated for weight loss, according to Benjamin Liu, another resident physician at Case Western and co-author of the study.
Liu expressed optimism about the current findings. “It’s very exciting, especially since it’s a noninvasive strategy compared to bariatric surgery, and many more patients will be open to it,” he said.
