Scientists have confirmed that metabolic syndrome, a constellation of conditions that increases the risk of heart disease and diabetes, may also increase the risk of the two most common types of liver cancer, according to data presented at the AACR 102nd Annual Meeting 2011, held here April 2-6. Katherine McGlynn, Ph.D., a senior investigator at the National Cancer Institute, said approximately one-third of the U.S. population has metabolic syndrome, which is defined as the co-occurrence of at least three of the following five conditions: raised blood pressure, elevated waist circumference（腰围） , low HDL or "good" cholesterol, raised triglyceride（甘油三酸酯） levels and raised fasting plasma glucose levels.

According to McGlynn, persons with these conditions may be at increased risk of developing hepatocellular carcinoma（肝细胞癌） and intrahepatic（肝内的） cholangiocarcinoma.

Liver cancer incidence has been rising since the 1980s in the United States. The factors related to the increase are not well understood. "A lot of attention has focused on viral risk factors, but a significant part of the increase may be due to metabolic syndrome, as well as to diabetes and obesity," said McGlynn.

"The prognosis for liver cancer is only marginally better than the prognosis for pancreatic cancer, with a five-year survival of approximately 10 percent," she said. "Prognosis is more favorable, however, when liver cancers are diagnosed at early stages when they are small and localized to the liver."

For the current study, researchers identified 3,649 cases of hepatocellular carcinoma and 743 cases of intrahepatic cholangiocarcinoma. They compared the medical history of these patients with the medical histories of 195,953 cancer-free adults.

Statistical analyses showed that the persons with liver cancer were significantly more likely than cancer-free persons to have a prior history of metabolic syndrome: 37.1 percent of patients with hepatocellular carcinoma had pre-existing metabolic syndrome, as did 29.7 percent of patients with intraheptic carcinoma; only 17.1 percent of the cancer-free adults had metabolic syndrome.