Etiology of non-B non-C hepatocellular carcinoma in the eastern district of Tokyo

This study was carried out to clarify the carcinogenic factors associated with nonviral hepatocellular carcinoma (HCC). A total of 320 HCC patients diagnosed and treated from January 2000 to December 2006 were enrolled. The clinical characteristics of non-B non-C HCC patients were examined to determine possible carcinogenic factors. Of 320 HCC patients, 64 were classified as having non-B non-C HCC. The proportion of non-B non-C HCC increased from 17.8% in 2000 to 28.6% in 2006. Non-B non-C HCC patients had a significantly higher rate of early stage cirrhosis (Child-Pugh classification) than viral HCC patients. Significantly fewer non-B non-C HCC patients had periodic intensive medical assessments than viral HCC patients. Forty-five non-B non-C HCC patients were habitual alcohol drinkers, ten had nonalcoholic fatty liver disease (NAFLD), and seven had no apparent etiology. In habitual drinkers, the stage of underlying liver disease varied widely, while most NAFLD patients had early stage cirrhosis. On the other hand, more than half of the patients with HCC of undetermined etiology had noncirrhotic liver disease. Among habitual drinkers, the underlying liver disease was more progressive, and the T stage was more advanced in those with high daily alcohol intake than in those with low daily alcohol intake. Periodic intensive medical assessments were crucial for detecting early stage HCC. Alcohol consumption and NAFLD may be important etiological factors in non-B non-C HCC. Periodic medical assessments for all patients with non-B non-C cirrhosis are crucial for early diagnosis and curative therapy.