Smoking habits and their relationship to precancerous lesions of the larynx.

Histologic findings in vocal cord specimens of 148 male autopsy cases (ages 15--91) were compared to a retrospective anamnesis of smoking habits. The relative frequency of normal squamous epithelium is 83.3% in nonsmokers, gradually decreasing from 56.3% in light to 45.8% in moderate, and finally 30.6% in heavy smokers. Ex-smokers were found to return to approximately the level of light smokers (54.2%). Precancerous lesions (dysplasia and carcinoma in situ) and carcinoma were found at lowest rates in non-smokers (4.2%) rising accordingly from 12.5% in light to 22.9% in moderate, and to 47.2% in heavy smokers, and returning to the level of light smokers (12.5%) in ex-smokers. Rates of relative frequency were rather similar, if less drastic, for hyperplastic and parakeratotic or keratinizing epithelial changes. The evaluation of lifetime tobacco consumption correlated to histologic findings in individual cases revealed an analogous pattern. Results suggest a very clear relationship between changes of vocal cord epithelia, and the quantities of tobacco consumed over a lifetime. They provide additional arguments in favor of the term "dysplasia" which, currently used to define precancerous lesions in various organs, may be suitably adopted for the morphological classification of precancerous changes of vocal cord epithelium.