The Copenhagen case-control study of renal pelvis and ureter cancer: role of analgesics.

Analgesic intake was investigated for 96 patients with cancer of the renal pelvis and ureter (including papillomas) and 294 hospital controls. In comparison with persons who never used analgesics, increased relative risks (RR) were seen for users of phenacetin-containing drugs after adjustment for smoking and high-risk occupational exposure (men: RR = 2.4; women: RR = 4.2). A significant relative risk for aspirin use among women was also observed. There was an indication of a dose-effect relationship for both types of analgesics. The influence of phenacetin and aspirin on the development of renal pelvis and ureter tumours could not be separated since in this study the two compounds occurred so frequently in the same formulation. Experimental studies and phenacetin metabolism makes it biologically most relevant to attribute the observed association in the present study to the phenacetin component of the drugs.