A new study has found that the metabolic syndrome is a major risk factor for the development of two forms of primary liver cancer.
The risk factors for hepatocellular carcinoma (HCC), the most common type of liver cancer, are chronic infection with hepatitis B and C viruses and excessive alcohol consumption.
Intrahepatic cholangiocarcinoma (ICC), the second most common type of liver cancer, is associated with primary sclerosing cholangitis and inflammatory bowel disease.
However, the cause of up to half of HCC and ICC remains unknown.
Metabolic syndrome comprises a group of medical conditions, which include central obesity (excess abdominal-area weight), raised fasting glucose levels and diabetes mellitus, raised triglycerides, reduced HDL cholesterol, and hypertension.
For the present study, lead researcher Tania Welzel, M.D., of the National Cancer Institute and Klinikum der J.W. Goethe-Universit?t examined the association between metabolic syndrome and development of primary liver cancers in the general U.S. population.
Using the SEER-Medicare database, researchers identified individuals diagnosed with HCC or ICC between 1993 and 2005.
A 5 percent sample of individuals residing in geographic regions similar to SEER registries was selected for comparison purposes. A total of 3649 HCC cases, 743 ICC cases, and 195953 individuals without cancer were identified and met study inclusion criteria.
Analyses showed metabolic syndrome was significantly associated with increased risk of HCC (odds ratio=2.13) and ICC (odds ratio=1.56).
"Our findings show a 2-fold increased risk for HCC and a 1.56-fold increased risk for ICC in those individuals with pre-existing metabolic syndrome," said Dr. Welzel.
"The risk of developing these primary liver cancers is significant for individuals with this condition. Due to the high prevalence of metabolic syndrome, even small increases in the absolute risk for HCC and ICC may contribute to the increasing liver cancer burden," she added.
The researchers said that metabolic syndrome may be the source behind a number of the idiopathic HCC or ICC cases and efforts to control the worldwide epidemics of obesity and diabetes could reduce the liver cancer burden.
The study is published in the August issue of Hepatology.