ACETAMINOPHEN, SOME OTHER DRUGS, SOME DISEASES AND THE RISK OF TRANSITIONAL-CELL CARCINOMA - A POPULATION-BASED CASE-CONTROL STUDY

The purpose of this study was to investigate the risk of transitional cell carcinoma among subjects with an intake of acetaminophen, aspirin , some other drugs and with some intercurrent diseases, The source per son-time ('study base') included subjects living in Stockholm in 1985- 1987, The study included 325 subjects with a transitional cell carcino ma of the urinary tract and 393 controls randomly selected from the so urce person-time, Data were obtained by a postal questionnaire supplem ented by a telephone interview, A relative risk (with a 95% confidence interval) of 1.6 (1.1-2.3) was obtained after an intake of acetaminop hen, adjusted for age, aspirin, gender and smoking, Conversely, a 30% decrease in risk was obtained after an intake of aspirin, No details i n the exposure substantiated the finding for acetaminophen. The inhere nt validity problems of observational studies, and the weak evidence i n this and previous studies of the association between acetaminophen a nd transitional cell carcinoma, makes available epidemiological eviden ce insufficient to regulate the use of this commonly ingested analgesi c, Increased risks were, in addition, found for tetracyclines, nitrofu rantoin and a history of allergic asthma and a decreased risk found fo r rheumatic symptoms, The findings stress the nonepidemiological data concerning the potential carcinogenicity of acetaminophen and may be a foundation for future research of some other drugs and diseases.