TOBACCO-SMOKE, RECURRENCES, AND P53 BCL-2 EXPRESSION IN BLADDER-CANCER/

Overexpression of p53 is considered to be predictive of mutations of t he p53 gene, Exposure-specific mutations of the p53 gene have been des cribed for cancers at different sites, An association between p53 muta tian/overexpression and smoking has been described in early stage blad der cancer, but results were conflicting, We have conducted a study on 131 bladder cancer cases, considering p53 expression and smoking habi ts in an area where the use of air-cured tobacco, rich in carcinogenic arylamines, is common, The study suggests that the use of air-cured t obacco induces p53 overexpression (possibly via mutation) in early sta ge-low grade bladder cancer, more frequently than flue-cured tobacco ( odds ratios = 3.4, 95% confidence intervals 0.9-13 in stage 1; odds ra tios = 24, 95% confidence intervals 1.1-519 in stage 1, grade 1). Howe ver, all the excess associated with air-cured tobacco was concentrated in recurrences, When available, the biopsies of recurrent cases with early-stage disease were re-examined and all shelved p53 expression at first diagnosis (with 10-50% of cells positive) (ir = 5), It is hypot hesized that exposure to tobacco-related chemicals increases the risk of recurrences via p53 overexpression/mutation. Expression of the bcl- 2 gene was detected in only 2 out of 13 p53-positive smokers.