Source Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kyoto Department of Internal Medicine and Gastroenterology, Tokyo Women's Medical University Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo Center of Gastroenterology and Hepatology, Saiseikai Suita Hospital, Suita Department of Gastroenterology and Hepatology, Kochi Medical School, Kochi Digestive Disease and Life-style Related Disease Health Research, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima Department of Gastroenterology, Otsu Municipal Hospital, Otsu Center of Liver Diseases, Kawasaki Hospital, Kawasaki Medical School, Okayama Department of Hepatology, Nanpuh Hospital, Kagoshima, Japan.

Aim:  Non-alcoholic steatohepatitis (NASH) can progress to hepatocellular carcinoma (HCC). We aimed to examine the clinical and pathological course of how NASH progresses to HCC.

Methods:  In this retrospective multicenter study conducted in Japan, we examined 19 patients (53% female), who had been previously diagnosed with histologically proven NASH and developed HCC during the follow-up period. The median age of the patients at the time of initial diagnosis of NASH was 65 years.

Results:  NASH progressed to HCC after a median follow-up period of 3.8 years (range: 0.5-11.6 years). All patients had been identified as having HCC during screening, which included 12 patients assessed by ultrasound, four patients assessed with computerized tomography, two patients that underwent serum des-γ-carboxy prothrombin testing and one patient that underwent serum α-fetoprotein testing. The median diameter of HCC tumors was 1.8 cm (range: 0.8-3.0 cm). The majority of patients (n = 13; 68%) presented with only one HCC tumor. The stage of liver fibrosis was significantly more advanced at the time of diagnosis of HCC than at the time of initial diagnosis of NASH, whereas there were no significant differences in the degree of steatosis.

Conclusion:  Screening for HCC with imaging is necessary not only in NASH patients with advanced fibrosis, but also in those with less advanced forms of fibrosis, particularly if they are old men. Liver fibrosis progresses to a more advanced stage during the development of HCC in NASH patients.