Smoking and hepatitis B-negative primary hepatocellular carcinoma.

Smoking histories were obtained from 79 patients with primary hepatocellular carcinoma (PHC) (of whom 40 were negative and 39 positive for serum hepatitis B surface antigen), 39 patients with liver cancer not primary in the liver (LCNP), and 204 hospitalized controls. All subjects were Caucasians of Greek nationality and residence. No significant difference in smoking habits was found between controls and either PHC patients positive for serum hepatitis B surface antigen or LCNP patients. In contrast, there was a highly significant association between smoking and PHC negative for serum hepatitis B surface antigen (P less than 10(-4)); this association was not accounted for by the greater alcohol consumption of smokers. The risk ratios were 1.3, 2.5, 3.7, and 8.4 for current smokers of 1-10, 11-20, 21-30, and 30+ cigarettes per day.