A retrospective study of renal cancer with special reference to coffee and animal protein consumption.

Interviews were obtained with 106 patients with adenocarcinoma of the renal parenchyma, 33 patients with carcinoma of the renal pelvis and 139 individually matched control patients. Comparison of the cancer patients with the control patients showed no evidence of a positive association between either type of renal cancer and coffee or animal protein consumption. Carcinoma of the renal pelvis was associated positively with cigareete consumption (relative risk estimate 1-8) and the daily consumption of analgesic tablets was more frequent in patients with cancer of the renal parenchyma than in their matched controls (14-2% compared with 1-9%,P less than 0.005). It appeared likely that the latter relationship was non-causal.