Medications routinely prescribed for type 2 diabetes may have unexpected effects on how certain cancers develop and progress, according to a recent scientific review. The findings suggest that some widely used drugs could influence tumour growth, immune responses, and inflammation, factors closely linked to cancer biology.
The review, published in Precision Clinical Medicine, was conducted by researchers from Peking University People’s Hospital and synthesises evidence from laboratory and clinical studies examining the relationship between anti-diabetic drugs and cancer outcomes. While diabetes itself is known to be associated with an increased risk of several cancers, the researchers focused on whether diabetes treatments might play a role beyond blood sugar control.
One drug of particular interest is metformin, a first-line therapy for type 2 diabetes used by millions worldwide. Evidence suggests that metformin may slow tumour growth by altering the tumour microenvironment and enhancing anti-cancer immune activity. The drug is also reported to affect key cellular pathways involved in cell growth and survival, including AMPK and mTOR signalling pathways.
Other commonly prescribed diabetes medications, such as SGLT2 inhibitors and GLP-1 receptor agonists, were also examined. Some studies indicate that these drugs may reduce inflammation and promote programmed cell death in cancer cells. However, their effects appear to vary depending on cancer type and the specific medication used, and results across studies remain inconsistent.
The review highlights that metformin has shown more consistent associations with reduced risk in cancers such as colorectal and liver cancer, whereas evidence related to breast cancer remains inconclusive. Researchers emphasise that these observations do not establish causation and should not yet influence clinical decision-making for cancer treatment.
Experts involved in the study caution that many questions remain unanswered. Long-term effects, cancer-specific responses, and interactions with existing cancer therapies require further investigation through well-designed clinical trials.
The authors conclude that a better understanding of how diabetes medications interact with cancer biology could support more personalised treatment strategies for patients managing both conditions. Future research may also explore whether existing diabetes drugs could complement conventional cancer therapies under carefully controlled settings.