Attributable risks for kidney cancer in northern Italy.

The percent population attributable risk (AR) for kidney cancer was estimated in relation to smoking habits, beta-carotene intake, history of cystitis and family history of kidney cancer, using data from a case-control study conducted between 1985 and 1989 in Milan, northern Italy. The data comprised 133 histologically confirmed cases of incident kidney cancer and 392 controls, admitted to hospital for a wide range of acute, non-neoplastic, non-smoking-related diseases. On the basis of multivariate odds ratios (ORs), smoking habits accounted for about 26% of cases, a low beta-carotene intake for 18%, a history of cystitis for 7%, and a family history of kidney cancer in first-degree relatives for 3% of cases. Ever smoking and low beta-carotene intake combined explained 38% of all kidney cancers, and the combination of these two factors plus a history of cystitis and a family history of kidney cancer explained 45% of the incidence of the disease. Thus, even if available, dietary information was limited and the AR estimates were based on somewhat arbitrary assumptions. A considerable proportion of kidney cancers could be avoided simply by eliminating smoking and increasing consumption of fruit and vegetables in this Italian population. This would mean that about 1,500 kidney cancer deaths every year in the whole of Italy could be avoided.