Drugs like Ozempic, Wegovy and Zepbound have revolutionized the treatment of obesity and diabetes. Now researchers are excited to see their potential impact on other conditions, including addiction and sleep apnea—and even cancer.
Scientists consider this class of drugs, called GLP-1 agonists, a breakthrough because they act on the brain to regulate the body’s hormones, slow digestion and suppress hunger. And in several recent studies, they show early signs of preventing many common cancers – including breast, colon, liver and ovarian cancer – that are known to be caused by obesity and excess weight.
“It’s a hopeful story, and frankly, it’s exactly what people need,” says Arif Kamal, a breast cancer oncologist and chief patient officer at the American Cancer Society.
Although research into GLP-1 drugs is still in its early stages, studies so far have been fairly consistent in showing their usefulness in preventing certain types of cancer. A research letter published in JAMA Oncology last year, for example, suggests that GLP-1 drugs may reduce the risk of colon cancer even in people who are not overweight. A more recent analysis in JAMA network opened suggests that GLP-1 offers diabetics far better protection against cancer than insulin treatments.
Another recent study presented at the American Society of Clinical Oncologists meeting in June showed that both bariatric surgery and GLP-1 drugs dramatically reduce the risk of the 13 obesity-related cancers. For those who underwent bariatric surgery, that risk dropped by 22% over 10 years compared to those who received no treatment. But for those who took GLP1 drugs, the risk dropped by a whopping 39%.
“And I think a 39% risk reduction is one of the most powerful risk reductions we’ve ever seen,” Kamal says.
GLP-1 agonists were originally developed nearly two decades ago to treat diabetes. In the last decade, regulators began approving them as weight-loss agents—first as liraglutide, sold under the brand name Saxenda, and more recently in the form of semaglutide or tirzepatide under brand names such as Wegovy and Zepbound.
When it comes to cancer prevention, scientists note that the relationship between obesity and cancer is complex and closely interrelated. Cancers associated with obesity are particularly common in organs involved in digestion and metabolism, such as the liver and pancreas, as well as gynecological cancers, including breast and uterine cancer. The reproductive organs are very sensitive to the hormone estrogen, which causes rapid cell growth, for example during pregnancy.
But Kamal says there is also a particularly close relationship between estrogen and cancer. “What we know is that estrogen in particular – and possibly some other hormones, but estrogen definitely – promotes the growth of many types of cancer,” he says. And fat cells increase estrogen production.
This means that women are increasingly vulnerable to cancer today. In the past, men were at much higher risk of cancer – mainly because they were more likely to engage in risky behaviors such as smoking or drinking, says Kamal. But in recent years, the high prevalence of obesity in both men and women has led to this gender gap closing.
Obesity is also probably the main reason for the rising cancer rate among younger adults, he says – just like tobacco in previous generations.
“Unhealthy weight is due to our generation’s smoking,” says Kamal.
This is why the evidence that GLP-1 drugs could help reduce this risk is so significant.
Furthermore, this ASCO study suggests that GLP-1 drugs have a noticeable impact on cancer risk even when patients don’t lose much weight by taking these drugs. In other words, the drugs appear to act on a number of the body’s own mechanisms to reduce susceptibility to cancer.
“We think the protective effect of GLP-1 is probably multifactorial,” says Cindy Lin, a resident physician at Case Western Reserve and co-author of the June ASCO study. “Part of it is (weight) loss, but other factors may also play a role – better glycemic control, anti-inflammatory effects.”
Further research is necessary and inevitable – especially studies of the newer formulations of GLP-1 drugs for weight loss, says Benjamin Liu, another resident at Case Western and co-author of the ASCO study.
He says the data so far is encouraging. “It’s very exciting, especially because it’s a more noninvasive strategy compared to bariatric surgery and many more patients will be open to it.”
Copyright: NPR
