Diabetes drug may protect against liver cancer

Metformin, the widely used medication to treat diabetes, may protect against liver cancer, according to research published in the journal Cancer Prevention Research.

The study conducted by the University of Maryland School of Medicine is the first to evaluate the effect of metformin on hepatocellular carcinoma, the most common type of primary liver cancer. Previous studies have associated metformin with cancer prevention.

Geoffrey Girnun, lead author of the study, and his team gave metformin to mice with liver tumors. Those mice showed minimal tumor activity, while mice not taking metformin displayed significant tumor growth.

The researchers found that the common diabetes drug helped prevent cancer by inhibiting the liver's lipid synthesis that is know to promote cancer.

Lipid synthesis is associated with diabetes, obesity, hepatitis and nonalcoholic fatty liver disease, putting patients with these diseases at highest risk for liver cancer.

Treating clinicians may already prescribe metformin to their patients living with diabetes, thereby providing the protective benefits to the liver described by Girnun's research.

Further research is needed to confirm if these cancer prevention benefits are transferable to other patient populations at high risk for liver cancer.

Diabetes and liver cancer
Diabetes is the most common risk factor for liver cancer in the US, according to the National Cancer Institute. The rate of liver cancer has increased in the US for several decades. The rate of type 2 diabetes has also significantly increased in the past several decades as well.

Other risk factors for liver cancer include infection with hepatitis B virus or hepatitis C virus, consuming two or more alcoholic drinks a day for several years, exposure to aflatoxin made by certain types of mold, iron storage disease, cirrhosis of the liver, and obesity.

Early liver cancer is often asymptomatic, according to the National Cancer Institute. Once the cancer grows larger, people may notice one or more common symptoms including pain in the upper abdomen on the right side, a lump or a feeling of heaviness in the upper abdomen, swollen abdomen, loss of appetite and feelings of fullness, weight loss, weakness or feeling very tired, nausea and vomiting, jaundice causing yellow skin and eyes, pale stools, and dark urine, and fever.

Sources: Cancer Prevention Research, National Cancer Institute