Background: In Germany about 20000 new cases of urothelial cancer (UC) and about 7500 deaths from bladder cancer alone occur each year. Among the manifold risk factors, little research has been done on the role of smoking and the habitual intake of analgesics and laxatives-practices that are common in parts of the German population. The aim of this study is to define the proportion of risk derived from these preventable habits for the development of UC at its different sites. Subjects and methods. A case-control study in the area of the former West Berlin was performed from 1990 to 1995 including all newly diagnosed incident cases of UC from the eight hospitals of the study area. Study subjects and population-based controls individually matched by age (+/-2 years) and sex were evaluated by a standardized face-to-face interview about the lifelong exposure to cigarette smoking, analgesics, and laxatives. Adjusted risk analysis was carried out for the main exposure variables in relation to the different sites of UC in the bladder, ureter, and renal pelvis.
Results: Six hundred and forty-seven cases of UC (571 bladder, 25 ureter, and 51 renal pelvis) and an identical number of controls were included in the analysis (response rate in cases, 84.6%; in controls, 70.2%). Smoking increased the risk of bladder cancer (BC) by an odds ratio (OR) of 3.22 (95% confidence interval (CI) 2.29-4.52), that of ureter (URC) or renal pelvis cancer (RPC) together by OR 6.20 (95% CI 2.04-18.81), and that of RPC alone by OR 5.91 (95% CI 1.47-23.66). Ex-smoking was associated with an increased risk for BC (OR 1.55, 95% CI 1.10-2.19). Intake of more than 1 kg of phenacetin in analgesic mixtures was associated with an OR of 5.28 for RPC (intake of > or = 1 kg paracetamol, OR 3.27; > or = 1 kg pyrazolones, 1.12) and 0.75 for BC (not significant). Laxatives significantly increased the risk of BC (OR 2.14, 95% CI 1.26-3.63) and RPC/URC (OR 9.62, 95% CI 1. 01-91.24) in both sexes.
Conclusion: Habitual risks from smoking and intake of laxatives significantly contribute to the development of UC, especially of the renal pelvis and ureter cancer. Intake of at least 1 kg of analgesic substances (anilides, pyrazolones) as calculated from this study base is associated with increased but not significant risks for RPC. These data underline that restrictive and educational measurements focusing on common habits would have a strong impact on preventing UC in Germany.