Background: This study evaluated the prevalence and risk of developing oral leukoplakia in smokeless tobacco, or ST, users and the response of these leukoplakic lesions after six weeks of involuntary tobacco cessation. U.S. Air Force basic military training provided an environment of a mandatorily tobacco-free setting.
Methods: The authors designed their investigation as a case control study with a nested cohort study. The principal investigator (G.C.M.) conducted oral examinations of 3,051 male U.S. Air Force basic military trainees. Using a questionnaire, he obtained detailed information concerning subjects' ST use patterns before basic training. Clinical photos were taken of all leukoplakic lesions identified in ST users at the initial examination and again six weeks later.
Results: Of the 3,051 male trainees examined (mean age = 19.5 years), 9.9 percent (302/3,051) were identified as current ST users. Among current ST users, 39.4 percent (119/302) had leukoplakia vs. 1.5 percent (42/2,749) of nonusers of ST (odds ratio = 41.9, 95 percent confidence interval = 28.1-62.6). At the end of the involuntary cessation of tobacco use, 97.5 percent of these leukoplakic lesions had complete clinical resolution. The type of ST used (snuff vs. chewing tobacco), amount used (cans or pouches per day), length of use (months), number of days since last use and brand of snuff used were significantly associated with the risk of developing leukoplakic lesions among ST users.
Conclusions: The important new finding from this investigation is that if a young, otherwise healthy man with leukoplakic lesions stops using tobacco for six weeks, most of his leukoplakic lesions will resolve clinically. Use of ST, specifically snuff, is strongly associated with development of oral leukoplakia in young adult men.
Clinical implications: The clinician can use these findings in deciding when to perform biopsies on leukoplakic lesions associated with ST use. This information also should be used to assist ST users in quitting this addictive behavior.