Researchers have discovered that a hormone -- present at higher levels in women -- can keep them away from liver cancer, suggesting the disease is more common in men.

The study showed that a potential contributor to this gender disparity is adiponectin, a hormone secreted by fat cells that helps control the body's metabolism. The hormone activates two proteins inside liver cells, known as p38 and AMPK, that block cell proliferation and impair tumour growth, said the study, published in the Journal of Experimental Medicine. "Circulating adiponectin levels have been reported to be higher in women than in men," said Guadalupe Sabio at the Spanish National Center for Cardiovascular Research (CNIC) in Spain.

Similar to humans, male mice are more also prone to hepatocellular carcinoma (HCC) -- the most common form of liver cancer -- than females, as the increased levels of adiponectin in female mice protect them from HCC, the study said. Inhibiting testosterone production in male rodents increased their adiponectin levels and reduced tumour growth.

Importantly, the study suggested that adiponectin and metformin -- a common antidiabetic drug -- could be used as novel treatments for liver cancer. Sabio said that adiponectin's role in HCC is controversial and needed further investigation. Liver cancer is the fourth leading cause of cancer-related deaths worldwide.