Millions of people already use these drugs to treat obesity. Now, a series of studies suggest they could play a role in preventing and treating cancer as well.

GLP-1 Medications and Breast Cancer Risk

One analysis found that those who took GLP-1 medications were 30% less likely to develop breast cancer compared with those not taking weight-loss drugs. This is significant, as breast cancer is the most common form of the disease worldwide.

A second study found that adding weight-loss drugs to standard breast cancer treatment reduced the risk of patients dying from the disease by 30%.

A third study, involving patients with breast, lung, bowel, or liver cancer, found that those on weight-loss drugs were up to 50% less likely to experience their disease spreading to more advanced stages.

GLP-1 Medications and Their Role in Cancer Research

GLP-1 medications are a class of drugs that mimic a natural hormone in the body called glucagon-like peptide-1. These drugs help regulate blood sugar and appetite. Originally used to treat type 2 diabetes, they are now widely used for weight management.

The first study, a retrospective analysis of 110,000 women aged 45 to 80, found that those who took GLP-1 medications were 30% less likely to develop breast cancer than those who did not. The findings were presented by Dr. Elizabeth McDonald, a professor of radiology at the University of Pennsylvania and a breast radiologist at the Abramson Cancer Center.

McDonald said: “While our study was observational and does not definitively confirm an association between GLP-1 medications and reduced breast cancer incidence, it does add to the growing body of evidence suggesting that it’s worth investigating these weight-loss drugs as potential cancer prevention tools.”

She added that GLP-1 medications are intriguing from a cancer research perspective because they weren’t designed for cancer therapy but do affect many different targets and pathways associated with cancer development.

GLP-1 medications are highly effective at helping people lose weight. Maintaining a healthy weight has long been recommended as a way to ward off breast cancer. Being overweight or obese, particularly after menopause, is a known risk factor for the disease.

Researchers have also long suspected that low-grade inflammation may play a role in breast cancer development. GLP-1 medications reduce systemic inflammation via different pathways and have other metabolic and epigenetic effects that could inhibit tumour growth.

Further Research and Mixed Reactions

The second study, involving 27,000 breast cancer patients, was led by the IRCCS Istituto Romagnolo per lo Studio dei Tumori Dino Amadori, a cancer centre in Meldola, Italy. Researchers found that adding weight-loss drugs to standard treatment was associated with a 30% reduced risk of death.

The third study, involving 12,000 cancer patients and led by the Cleveland Clinic, found that in lung, breast, bowel, and liver cancer, people who took weight-loss drugs were 38% to 50% less likely to develop stage-four forms of the disease than those who did not.

Dr. Marcin Chwistek, the director of the supportive oncology and palliative care programme at Fox Chase Cancer Center in Philadelphia, who was not involved with the research, said: “GLP-1 receptor agonists have never been just glucose-lowering drugs. Their anti-inflammatory and immune-modulatory properties have long suggested broader effects.”

Dr. Eleonora Teplinsky, the head of breast and gynaecologic medical oncology at Valley Health System in New Jersey, who also was not involved with the research, said the evidence was not clear yet as to whether the potential benefits of weight-loss drugs in the fight against cancer were just due to weight loss or other factors.

“I think there is enough data to show there is clearly some impact on either cancer risk or the risk of recurrence, but we haven’t yet defined it exactly,” she said. “We need to do more studies putting patients on them and seeing what happens. There are also signals that they may help with side-effects. My patients who are on GLP-1s often feel better and it helps with a lot of the side-effects from their hormone blockers. Interest in this area is climbing exponentially. It’s a very hot topic right now and hopefully we can capitalise on that.”