A nationwide survey on non-B, non-C hepatocellular carcinoma in Japan: 2011-2015 update.

Background: We previously reported that the incidence of hepatocellular carcinoma (HCC) with non-viral etiologies increased rapidly between 1991 and 2010 in Japan.

Methods: To update this investigation, we enrolled patients who were initially diagnosed as having non-B, non-C HCC at participating hospitals between 2011 and 2015. In addition to the patient characteristics investigated in the previous report, we also investigated the duration of alcohol consumption. The overall survival rate was analyzed using the Kaplan-Meier method, and the hazard function against the body mass index (BMI) was plotted using cubic splines.

Results: A total of 2087 patients were enrolled. The proportion of patients with non-viral etiologies has continued to increase from 10.0% in 1991 to 32.5% in 2015. Patients were also older (median ages, 70-73 years) and more obese (median BMIs, 23.9-24.2 kg/m), and the proportions of patients with diabetes mellitus (46.1% to 51.6%), hypertension (42.7% to 58.6%), dyslipidemia (14.6% to 22.9%), and fatty liver (24.0% to 28.8%) had all increased significantly. There was a significant inverse relationship between the duration and the amount of daily alcohol consumption. The improvement in the overall survival was relatively small, with a decreased proportion of patients under surveillance (41.3% to 31.6%). A hazard function plot showed a curve similar to that in our previous report, with a lowest hazard of ~ 26 kg/m.

Conclusions: The proportion of HCC patients with non-viral etiologies continues to increase in Japan. Lifetime total amount of alcohol consumption may be a risk factor.