Risk Factors For Liver Cancer Identified in Asymptomatic HCV

NEW YORK DEC 23, 2004 (Reuters Health) - High alanine aminotransferase (ALT) levels, male sex, advancing age and lower serum cholesterol all increase the risk that patients with asymptomatic hepatitis C virus (HCV) infection will develop hepatocellular carcinoma (HCC), Japanese researchers report.

While HCV infection is a known risk factor for HCC, Dr. Hideo Tanaka of the Osaka Medical Center for Cancer and Cardiovascular Diseases and colleagues note, it is unclear what percentage of people with asymptomatic infection will go on to develop cancer.

To investigate, the researchers looked at a group of individuals 40 years or older who donated blood between 1991 and 1993, some of whom were found to have HCV infection. Study participants included 1927 individuals with HCV but without hepatitis B virus (HBV) infection; 2519 HBV-infected individuals who were HCV negative; 25 people infected with both HBV and HCV; and 150,379 seronegative controls. The subjects were followed until December 31, 2000 or a diagnosis of HCC, for a mean follow-up of 99 months.

Among men with HCV, the cumulative risk of developing HCC was 21.6%, while the risk for women was 8.7%. HCC risk increased in tandem with rising ALT levels, and also increased as baseline serum cholesterol levels dropped. Cancer risk increased with age among both men and women.

Two thirds of individuals with HCV infection had low ALT levels at baseline, and their risk of HCC was low, while the one third with high ALT had an incidence of HCC similar to that seen among people diagnosed with chronic hepatitis.

Among individuals with both HCV and HBV infection, HCC incidence over 9 years was 12%, compared to 3% for those with HCV only and 2% for those with HBV only.

The findings underscore the importance of developing effective HCV screening programs in countries where the infection is prevalent, the researchers conclude.

SOURCE:

• International Journal of Cancer 2204;112:1075-1080.