Dietary patterns and risk of cancers of the upper aerodigestive tract: a factor analysis in Uruguay.

In the time period 1996-2004, we conducted a case-control study in Montevideo, Uruguay with the objective of exploring the role of foods and alcoholic beverages in the etiology of cancers of the upper aerodigestive tract (UADT). In brief, 563 male cases and 1099 male controls were frequency matched on age and residence using random sampling. All the participants were drawn from the 4 major public hospitals in Montevideo. We used exploratory factor analysis among controls. Through Scree plot test, the model retained 4 factors, which were labeled as prudent, starchy plants, Western, and drinker. These dietary patterns explained 34.8% of the total variance. Whereas the prudent pattern was inversely associated with UADT cancer [odds ratios (OR) for the upper tertile vs. the lowest one 0.52, 95% confidence intervals 0.32-0.76, P value for trend = 0.0005), the remaining patterns were significantly and positively associated with UADT cancers. We conclude that these patterns were similar among the oral and laryngeal cancers, both in the direction of the ORs and in the magnitude of the associations, suggesting that these cancer sites share the effect of dietary patterns in the etiology of cancer of the upper aerodigestive tract.