Background: Age-adjusted liver cancer mortality rates have been increasing for both men and women in Japan since 1970; however, increases in mortality rates in men are much greater than those in women. Hepatitis C virus infections and heavy alcohol consumption are considered to be the major risk factors of liver cancer deaths in Japanese. The purpose of this study is (1) to examine the pattern of liver cancer mortality by gender and birth year to compare those with the pattern of other alcohol-related mortality and (2) to estimate the attributable risk per cent of heavy alcohol consumption for liver cancer deaths in Japanese men.
Methods: Age-specific liver cancer mortality rates by gender were compared with those of cirrhosis mortality rates. Then male-to-female mortality rate ratios were calculated by birth cohort and compared with cirrhosis mortality rate ratios and oesophageal cancer mortality rate ratios. The attributable risk per cent of alcohol consumption for liver cancer death was calculated, using female liver cancer mortality rates as standard rates.
Results: Examination of both gender and birth cohort mortality rates revealed that male-to-female liver cancer mortality rate ratios by birth cohort correspond well with those rate ratios for liver cirrhosis and oesophageal cancer mortality. The attributable risk per cent of alcohol consumption for liver cancer deaths in Japanese men was 70%.
Conclusion: Alcohol consumption is more important than hepatitis C virus infections as a major cause of liver cancer deaths in Japanese men.