Drinking of maté and the risk of cancers of the upper aerodigestive tract in Latin America: a case-control study.

Cancers of the upper aerodigestive tract (UADT: oral cavity, oropharynx, hypopharynx, larynx, esophagus) have high incidence rates all over the world and they are especially frequent in some parts of Latin America. In this study, we have evaluated the role of the consumption of maté, a hot herb-based beverage, based on 1168 UADT squamous-cell carcinoma cases and 1,026 frequency-matched controls enrolled from four centers in Brazil and Argentina. The effect of maté drinking on the risk of head-and-neck cancers was borderline significant. A significant effect was observed only for cancer of the esophagus (OR 3.81 (95% CI 1.75-8.30)). While duration of maté drinking was associated with the risk of all UADT cancers, the association with cumulative maté consumption was restricted to esophageal cancer (p-value of linear trend 0.006). The analyses of temperature at which maté was drunk were not conclusive. The increased risk associated with maté drinking was more evident in never-smokers and never-alcohol drinkers than in other individuals. Our study strengthens the evidence of an association between maté drinking and esophageal cancer; the hypothesis of an association with other UADT cancers remains to be clarified.