On the way to another revolution: weight-loss injections may reduce breast cancer recurrence
New studies raise the possibility that drugs from the GLP-1 family, used to treat obesity and diabetes, may reduce the risk of breast cancer recurrence. However, at this stage, these are observational findings only.
A potential breakthrough in the fight against cancer: weight-loss injections, which have already revolutionized the treatment of obesity and diabetes and proven effective in reducing the risk of cardiovascular disease, kidney disease, and fatty liver, may offer an additional benefit. New studies presented at the American Society of Clinical Oncology (ASCO) conference suggest that treatment with GLP-1 family drugs may be associated with a reduced risk of breast cancer recurrence. However, experts emphasize that it is too early to draw clinical conclusions, and current evidence is insufficient to recommend these drugs for this specific purpose.
The findings were presented at the annual ASCO conference in Chicago. Researchers examined women treated with GLP-1 drugs—including Ozempic, Wegovy, and Mounjaro—and identified a link between their use and a lower rate of breast cancer recurrence. Data also pointed to a potential decrease in the risk of developing the disease in the first place.
Experts stress that these studies were observational. This means they identified a statistical correlation but cannot prove that the drugs are the direct cause of the reduction in cancer recurrence. It is possible that part of the effect is related to other factors characteristic of the patient population receiving these treatments.
One primary hypothesis is that the effect stems from metabolic changes rather than a direct action on cancer cells. These drugs cause significant weight loss, thereby reducing adipose tissue. It is well-established that obesity increases the risk of various cancers, particularly breast cancer post-menopause.
Adipose tissue is not merely an energy store; it produces estrogen, a hormone that promotes the growth of certain breast tumors. Weight loss reduces hormone levels, which may in turn lower the risk of recurrence in some women.
Furthermore, obesity is associated with low-grade chronic inflammation. Recent evidence suggests that an inflammatory environment can encourage cancer progression. Since GLP-1 drugs have been shown to reduce markers of chronic inflammation, this mechanism may also contribute to the observed effect.
To prove a causal link, randomized controlled trials—the gold standard in medical research—are required. Such studies specifically regarding the prevention of breast cancer recurrence using GLP-1 drugs have not yet been published.
Experts emphasize that these drugs are not a substitute for standard breast cancer treatments, such as surgery, radiation, chemotherapy, or hormonal therapy. Women receiving weight-loss injections must continue oncological follow-up and adhere to all treatments recommended by their medical team.
For women suffering from obesity, especially after menopause, there may be an additional benefit if they are treated with these injections within approved clinical indications. However, the decision to start treatment should be made only after an individual medical assessment and not based on the expectation that the drug will prevent cancer or its recurrence.
