PURPOSE: Quitting smoking may prevent oral cancer. Behavioral intervention to quit smoking may be more efficient if persons are assigned an individual risk of cancer.
PATIENTS AND METHODS: In this prospective study, we provided counseling and behavioral intervention toward smoking cessation, supplemented by genetic analyses in clinically normal oral mucosa of heavy smokers. Measurement of serum cotinine was used to assess changes in smoking habits.
RESULTS: In cytologic scrapings from 275 heavy smokers with clinically normal mucosa, we found tetraploidy in four and aneuploidy in 19 persons (23 of 275; 8%). Twenty one (91%) of 23 persons with aneuploidy had quit or reduced their smoking habits at the 3-month follow-up, 20 (87%) of 23 persons had done so at 12 months, and 21 (91%) of 23 persons had done so at 24 months. Fifty-one (20%) of the 252 persons without genetic changes in their mucosa had quit or reduced their tobacco habits at the 3-month follow-up, 23 (9%) had done so at 12 months, and 17 (7%) had done so at 24 months (P < .001). After 24 months, normalization of DNA content to diploidy was observed in two of four persons with tetraploid (50%), and in 11 of 19 persons (58%) with aneuploid scrapings. One patient developed an oral carcinoma in the floor of the mouth: this patient had an aneuploid scraping obtained 43 months earlier and developed a leukoplakia 28 months before the carcinoma.
CONCLUSION: Risk markers of oral cancer are present in clinically normal mucosa of heavy smokers, and such findings enhance the adherence to smoking cessation on counseling. Cytogenetic aberrations may normalize after quitting smoking.
Supported in part by grants P01 CA106451 from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services; The Norwegian Cancer Society (E 03010/002, E 03010/003, and HF-51019); and the Research Foundation of the Norwegian Radium Hospital (702526-13, SE 0207, and SE 0411), as well as contributions from Astrid and Birger Torstedts Legat and Søren Bothner's Legat.
Authors' disclosures of potential conflicts of interest are found at the end of this article.