Preventive effect of HB vaccination against liver cancer: an estimation by simulation

In order to analyze the rapidly rising male mortality rate from liver cancer and to estimate the preventive effect of large-scale hepatitis B vaccination, we calculated the future number of deaths from liver cancer and cases of hepatitis B-related liver cancer by the linear/curved regression technique and the simulation method. Published statistics and research data were utilized for the calculation. The results of the calculation showed: 1) the increase in number of deaths from liver cancer for males would continue at the same rate as today, 2) this increase in number of deaths from liver cancer was caused by factor(s) not related to hepatitis B infection, 3) the ratio of hepatitis B virus horizontal infection to vertical infection has been sharply decreasing since the 1970s. The effect of the decrease of hepatitis B virus horizontal infection on the prevention of liver cancer is expected to be larger and to appear at an earlier stage than the effect of large-scale hepatitis B vaccination in Japan.