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 c ancers 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. H owever, the p53 mutation spectrum of current smokers differed significantly from the pattern for non-smokers and ex-smokers. Differences between the t wo populations included multiple mutations in the current-smokers and an ab sence in non- and ar-smokers (p <0.01), with the predominance of G:C to A:T transitions at CpG sites in nonsmokers (60.0%) in comparison with current smokers (7.6%) (p <0.02). Moreover, G:C to TA 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-s moke carcinogens and that the habit of smoking increases the extent of DNA damage.