FRIDAY, Jan. 6, 2012 (HealthDay News) -- Two new studies from the Mayo Clinic find that hepatitis C infection and obesity could be to blame for a surge in liver cancer cases, which have tripled over the last 30 years.
Late-stage hepatocellular carcinoma (HCC), or liver cancer, has only a 10 percent to 12 percent five-year survival rate, according to figures in a Mayo news release. The researchers say their findings could help doctors diagnose the disease earlier and save lives.
Both studies appear in the January issue of Mayo Clinic Proceedings
"The studies illuminate the importance of identifying people with risk factors in certain populations to help catch the disease in its early, treatable stages," said Dr. W. Ray Kim, a gastroenterology and hepatology specialist and principal investigator of one study, in the release.
The researchers examined several decades of medical information from the Rochester Epidemiology Project -- a national database on inpatient and outpatient care. Although the U.S. National Cancer Institute estimates the rate of HCC is 5.1 cases per 100,000 people, the new study found a higher rate of 6.9 per 100,000.
The researchers also found that hepatitis C is a risk factor for HCC. "The liver scarring from hepatitis C can take 20 to 30 years to develop into cancer," Kim said. "We're now seeing cancer patients in their 50s and 60s who contracted hepatitis C 30 years ago and didn't even know they were infected."
The study also showed that 11 percent of HCC cases were linked to obesity, particularly fatty liver disease. "It's a small percentage of cases overall," Kim noted. "But with the nationwide obesity epidemic, we believe the rates of liver cancer may dramatically increase in the foreseeable future."
In a separate study, the researchers examined Somalis living in the United States, since Somalia is known to have a high rate of hepatitis B, another risk factor for HCC. The study found that a significant percentage of liver cancer cases among the Somalis were linked not only to hepatitis B but to hepatitis C as well.
"The study suggests that screening for hepatitis C would be helpful for the Somali population and would enable close surveillance of liver cancer among those at risk," said study lead author Abdirashid Shire in the release. "That would greatly improve treatment and survival of Somalis with this type of cancer."
The U.S. National Institutes of Health provides more information on liver cancer.