Report of the 16th follow-up survey of primary liver cancer.

In the 16th nationwide follow-up survey of primary liver cancer, 19,920 patients were newly registered as patients with primary liver cancer at 795 medical institutions in Japan over a period of 2 years (from January 1, 2000 to December 31, 2001). Of these patients, 94.5% had hepatocellular carcinoma (HCC) and 3.6% had intrahepatic cholangiocarcinoma (ICC). In addition, 21,268 follow-up patients were registered, and a valid response rate of 75.6% was obtained in these follow-up patients. In this study, epidemiological and clinicopathological factors, diagnosis and treatment were investigated in patients who were newly registered in the 16th follow-up survey. As additional statistics, the cumulative survival rates of newly registered patients in the 11th to 16th follow-up surveys were calculated for each histological type (HCC, ICC and combined HCC and ICC) by background factor(s) and treatment, respectively. Furthermore, in patients with HCC, the cumulative survival rates were calculated for several types of treatment (hepatectomy, local ablation therapy and transcatheter arterial chemoembolization). It is anticipated that this follow-up survey will contribute to future research and medical practice for primary liver cancer.