A growing body of evidence suggests that popular GLP-1 drugs, widely used for weight loss and diabetes, can provide protection against many types of cancer.

More than two dozen studies presented over the past few days at the American Society of Clinical Oncology meeting in Chicago found that patients taking the drugs showed lower risks of developing cancer and disease progression, better survival, and improved responses to some treatments, compared with people who were not taking the GLP-1s.

The studies included analyses of clinical records and real-world databases tracking patients taking Novo Nordisk's Wegovy or Ozempic, Eli Lilly's Zepbound or Mounjaro, or older GLP-1 treatments.

The studies were not designed to show how or why GLP-1 use might affect cancer treatment. But researchers believe by reducing inflammation, regulating insulin signaling and possibly engaging directly with tumor biology, they may contribute to a protective effect in cancer patients.

“Chronic inflammation is a fundamental biological pathway involved in the development and progression of many cancers,” said Dr Elizabeth Susan McDonald of the University of Pennsylvania.

McDonald on Tuesday (Jun 2) reported on a study of 110,000 women, showing those who took GLP-1 medications were up to 35 per cent less likely to develop breast cancer than those who did not.

While obesity itself is a known risk factor for certain cancers, the anti-inflammatory effects of GLP-1s will likely prove to have a role in cancer prevention, McDonald said.

BENEFITS ACROSS CANCER STAGES AND TUMOUR TYPES

GLP-1 drugs include semaglutide, the active ingredient in Wegovy, Ozempic and Rybelsus; tirzepatide, sold as Mounjaro and Zepbound, as well as Lilly's Trulicity, or dulaglutide, and Novo's older liraglutide, sold as Saxenda and Victoza.

Some of the strongest signals of benefit came from a study of more than 12,000 patients that showed GLP-1 use was associated with markedly lower odds of cancers advancing to metastatic disease, particularly in lung, breast, colorectal and liver cancers. 

People with those cancers who took liraglutide, pramlintide, dulaglutide, tirzepatide, lixisenatide, or semaglutide were 38 per cent to 50 per cent less likely to see the disease spread than people who took drugs from a different class of diabetes medicines known as gliptins.

Reduced cancer incidence, longer survival, and fewer metastases were also seen with...