Metformin appears to reduce the risk of blood cancer

Patients who are treated with metformin for type 2 diabetes are less likely to develop a myeloproliferative neoplasm (MPN). Myeloproliferative neoplasms are cancers that occur when the body produces too many red blood cells, white blood cells or platelets.

“Our team was interested in understanding what other effects we see with commonly prescribed treatments like metformin,” said Anne Stidsholt Roug, MD, PhD, chief physician at Aarhus University Hospital and clinical associate professor at Aalborg University Hospital in Denmark. “The anti-inflammatory effect of metformin interested us, as MPNs are very inflammatory diseases. This is the first study to investigate the association between metformin use and risk of MPN.”

The findings were published on May 17, 2024 in Blood Advances

The researchers compared metformin use by subjects diagnosed with MPNs to a matched population (2010 – 2018) from the Danish general population.

They found that 8.2% of the non-MPN control group had taken metformin, compared to 7% of people in the MPN group. Also, 2% of the controls had taken metformin for longer than 5 years, compared to 1.1% in the MPN group.

They found a protective effect of metformin in all subtypes of MPN when adjusting for potential confounders.

“A dose-response relationship supported the association with increasing treatment duration, in particular ≥5 years,” they said.

“We were surprised by the magnitude of the association we saw in the data,” said Daniel Tuyet Kristensen, MD, PhD student, at Aalborg University Hospital and lead author of the study. “We saw the strongest effect in people who had taken metformin for more than five years as compared to those who had taken the treatment for less than a year.”

“In conclusion,” the authors said. “metformin use was associated with significantly lower odds of an MPN diagnosis, indicating its potential cancer-preventive effect.”