Supraglottic and glottic carcinomas: epidemiologically distinct entities?

In the time period 1988-2000, a case-control study on laryngeal cancer was conducted in Montevideo, Uruguay. Four-hundred eighty-one (481) cases newly diagnosed and microscopically confirmed as squamous cell carcinomas were included. These cases were frequency matched with 481 nonneoplastic controls, admitted to the same hospitals as the cases. The purpose of our study was to compare odds ratios (ORs) by laryngeal subsite (supraglottis and glottis). ORs of supraglottic cancers displayed much higher risks than glottic carcinomas for most tobacco variables and for red wine intake. The differences between subsites were statistically significant, displaying heterogeneity between both subsites. Moreover, whereas black tobacco smokers displayed a significant increased risk of 1.7 (95% confidence interval [CI] 1.2-2.5) compared to smokers of blond (flue-cured) tobacco among supraglottic tumors, no effect of this type of tobacco was observed in glottic lesions. It could be suggested that concerning tobacco and alcohol effects, supraglottic and glottic squamous cell cancers are probably distinct epidemiologic entities.