Diabetes drug metformin may help protect against common skin cancers

A recent study suggests that metformin, a widely prescribed medication for type 2 diabetes, may reduce the risk of developing certain types of skin cancer.

Researchers found that people taking metformin were significantly less likely to be diagnosed with basal cell carcinoma (BCC) or squamous cell carcinoma (SCC), the two most common forms of skin cancer.

The study, led by Dr. Tiffany Libby, an assistant professor of dermatology at Brown University, was published in the Journal of Drugs in Dermatology. The findings strengthen existing evidence that metformin might act as a protective agent against non-melanoma skin cancers.

Skin cancer is the most commonly diagnosed cancer in the United States, with about 5.4 million cases of BCC and SCC reported annually, according to the American Cancer Society (ACS). Among these, BCC accounts for approximately 80% of cases.

Fortunately, deaths from these types of skin cancer are rare, with an estimated 2,000 to 8,000 deaths annually, in contrast to the more dangerous melanoma.

For this study, researchers analyzed data from a large and diverse health database maintained by the National Institutes of Health. They compared more than 8,000 people with basal cell carcinoma and over 4,100 patients with squamous cell carcinoma to a control group of healthy individuals.

Each cancer patient was matched with four healthy individuals of the same age, race, ethnicity, and sex to ensure comparable results.

The findings showed that metformin users had a significantly lower risk of developing both types of skin cancer. This protective effect was observed even after adjusting for other medications that could influence cancer risk.

However, one exception emerged: Black patients taking metformin did not experience the same reduced risk of squamous cell carcinoma.

The researchers speculated that this might be because SCC in Black patients often develops in areas not exposed to the sun and is more strongly associated with chronic inflammation or scarring—factors that metformin may not address.

Metformin’s protective effects may stem from its ability to regulate key biological processes. Researchers suggest that the drug may work by:

Disrupting Cancer Cell Growth: Metformin may block cancer cells’ access to energy and nutrients, making it harder for them to grow and spread.
Promoting Cancer Cell Death: The drug encourages the destruction of unhealthy cells while boosting the immune system’s ability to target and eliminate cancer cells.
Reducing Inflammation: Chronic inflammation is a known risk factor for cancer, and metformin helps reduce inflammatory responses in the body.
Preventing Tumor Blood Vessel Growth: Metformin inhibits the formation of new blood vessels that supply nutrients to skin tumors.

While the results are promising, the study highlights the need for further research to confirm metformin’s role as a preventive treatment for skin cancer. The drug’s effects on different racial groups, its mechanisms of action, and its potential as a broader cancer prevention tool require additional investigation.

In conclusion, metformin shows potential as more than just a diabetes medication. By reducing the risk of basal and squamous cell skin cancers, it could offer additional health benefits to millions of people.

However, further studies are needed to fully understand its protective effects and determine whether it could be used as a standard preventive measure against skin cancer.

If you care about skin health, please read studies about eating fish linked to higher risk of skin cancer, and Vitamin B3 could help prevent skin cancers.

For more information about health, please see recent studies about vegetable oil linked to spread of cancer, and results showing Vitamin D could help treat skin inflammation.

The study is published in the Journal of Drugs in Dermatology.