The epidemiology of renal cell carcinoma. A second look

Background. From 1973 to 1991, the incidence of kidney cancer in the United States increased by 35.4%. Methods. A multicenter, hospital‐based case—control study was conducted from 1977 to 1993 through an interview of 788 patients with renal cell carcinoma and 779 control subjects. Results. Compared with those who never smoked, the odds ratio (OR) for renal cell carcinoma among current cigarette smokers was 1.4 (95% confidence interval [CI] 1.02‐2.0) for men and 1.1 (95% CI 0.7‐1.6) for women. Among men, there was a rising trend in the odds ratios with increasing pack‐years of smoking (P < 0.01) but not with the number of cigarettes smoked per day. The OR among those currently smoking nonfilter cigarettes exclusively was 2.4 (95% CI 1.2‐4.9) for men and 2.0 (95% CI 0.4‐11.1) for women. No increased risk was observed among current smokers of filter cigarettes. Among men, the OR associated with chewing tobacco was 3.2 (95% CI 1.1‐8.7). Total alcohol consumption was unrelated to the risk of renal cell carcinoma. A joint effect was observed among subjects with a high body mass index who reported a history of hypertension (OR = 1.9, 95% CI 1.01‐3.5) for men and 3.2 (95% CI 1.3‐7.7) for women. Conclusion. High body weight and hypertension were related jointly to renal cell carcinoma. Smoking nonfilter cigarettes and long term cigarette smoking (≧30 years) was a predictor for renal cell carcinoma risk in men. No significant association was found between smoking and renal cell carcinoma in women.