Second cancer following cancer of the urinary system in Connecticut, 1935-82.

The risk of second primary cancer was assessed in persons who developed cancer of the urinary tract in Connecticut during 1935-82. Among 12,384 patients with a first primary tumor of the bladder or urethra, a second cancer was reported in 1,151 (or 9%). A significantly elevated relative risk (RR) of 1.23 was due to excess cancers of the lung, larynx, prostate, and kidney, and acute nonlymphocytic leukemia. Among 5,115 persons with a first primary tumor of the kidney, renal pelvis or ureter, a second cancer was reported in 374 (or 7%) that yielded a significantly elevated RR of 1.54 due to excess tumors of the bladder and prostate and second primary kidney neoplasms. The role of common etiologic factors, such as cigarette smoking, the multifocal tendency of tumors of the urinary tract, and heightened medical surveillance are discussed in relation to these findings.