Case-control study of hepatocellular carcinoma, occupation, and chemical exposures.

The relation of hepatocellular carcinoma (HCC) to occupation and chemical exposures was evaluated in a case-control study. The study included 80 cases and 146 matched hospital controls on whom a work history was obtained. No persuasively positive association between HCC and any particular occupation, industry, or chemical exposure was found. However, the relative rate (RR) of HCC for persons employed in highway construction compared with those never so employed is 5.0 with 95% confidence limits (CL), 1.0 to 26. The RR for farming occupations, 1.4 (95% CL, 0.7 to 2.9), is also slightly elevated. The RR for persons exposed to pesticides compared with those not exposed is 2.4 (95% CL, 0.9 to 6.5). Asphalt exposures are associated with a RR of 3.2 (95% CL, 0.9, 11). These findings are compared to the results of other epidemiologic studies.