Renal cancer and cigarette smoking in a 26-year followup of U.S. veterans.

The cigarette smoking habits of a cohort of almost 250,000 U. S. veterans were analyzed for their relationship to renal cancer. Information on smoking habits was collected in 1954 and in 1957 for nonrespondents to the first effort. Of the veterans, 84 percent returned their questionnaires. The cohort was followed for mortality until 1980, or 26 years. The followup of these military veterans, mostly of World War I, revealed 719 deaths from renal cancer, making this the largest study of renal cancer and cigarette smoking to date. Current smokers had a 47 percent increase in risk relative to nonsmokers. The relative risk for renal cancer increased significantly with the number of cigarettes smoked per day, from 1.31 for 1-9, 1.37 for 10-20, 1.60 for 21-39, and 2.06 for 40 or more. This analysis was unable to separate the risks of cigarette smoking for tumors of the renal parenchyma from those for tumors of the renal pelvis and ureter. However, the results suggest that almost one-fifth of all renal cancer deaths are attributable to cigarette smoking.