BLADDER-CANCER AND BLACK TOBACCO CIGARETTE-SMOKING - SOME RESULTS FROM A FRENCH CASE-CONTROL STUDY

A retrospective study was planned in the Herault (Mediterranean) regio n of France where bladder cancer mortality and incidence rates are hig h. In the present paper, variations in bladder cancer risk according t o various smoking-related variables, in particular time of exposure an d type of tobacco, are examined. This case-control study with 219 male incident cases and 794 male population controls randomized from elect oral rolls was carried out in 1987-89. Trained interviewers obtained i nformation on demographics, dietary habits (coffee, alcohol, artificia l sweeteners, vegetables, spices, etc.), occupational exposures and de tailed history of tobacco smoking (average number of cigarettes per da y, number of years of smoking, age at which they began and/or quitted smoking, use of filter-tip and type of. tobacco). The odds ratio (OR) for cigarette smokers versus non-smokers was greater than 5. Results f or number of cigarettes daily, duration of smoking and lifetime smokin g showed a highly significant dose-response relationship, which was co nfirmed when these variables were treated as continuous in a logistic regression model. Eighty-eight percent of the smokers used black tobac co. Quitting smoking did not result in a significant reduction in blad der cancer risk. Higher risks were associated with starting to smoke a t an early age (OR before age 13 versus after age 21 = 3.42; 95% CI 1. 07-10.9) and with black tobacco smoking (OR black versus blond = 1.63; 95% CI 0.73-3.64). Results suggest that black tobacco may be more har mful than blond tobacco and may have an early non-reversible role in b ladder carcinogenesis.