Influence of cigarette smoking on P53 gene mutations in bladder carcinomas.

Background: The aim of this study was to analyse the influence of cigarette smoking on bladder carcinomas.

Patients And Methods: 98 cases of bladder cancers were examined by single strand conformation polymorphism analysis of exons 5 to 9, followed by DNA direct sequencing.

Results: The incidence of p53 gene mutations was not significantly influenced by habitual smoking. However, the p53 mutation spectrum of current smokers differed significantly from the pattern for non-smokers and ex-smokers. Differences between the two populations included multiple mutations in the current-smokers and an absence in non- and ex-smokers (p<0.01), with the predominance of G:C to A:T transitions at CpG sites in non-smokers (60.0%) in comparison with current smokers (7.6%) (p<0.02). Moreover, G:C to T:A and G:C to C:G transversions were found solely in current smokers.

Conclusion: It would appear that, in current-smokers, the spectrum of p53 gene mutations is related to tobacco-smoke carcinogens and that the habit of smoking increases the extent of DNA damage.