Nutrient-based dietary patterns and nasopharyngeal cancer: evidence from an exploratory factor analysis

Background:To our knowledge, no study assessed the association between dietary patterns and nasopharyngeal carcinoma(NPC) in low-incidence areas.Methods:We examined this association in a hospital-based case–control study carried out in Italy between 1992 and 2008,including 198 incident NPC cases and 594 controls.A posterioridietary patterns were identified through principal componentfactor analysis performed on 28 nutrients and minerals derived from a 78-item food-frequency questionnaire. Odds ratios (ORs)and 95% confidence intervals (CIs) were estimated using unconditional multiple logistic regression models on tertiles of factorscores.Results:We identified five dietary patterns namedAnimal products,Starch-rich,Vitamins and fibre,Animal unsaturated fatty acids(AUFAs), andVegetable unsaturated fatty acids (VUFAs). TheAnimal product(OR=2.62, 95% CI=1.67–4.13, for the highestvslowest score tertile),Starch-rich(OR=2.05, 95% CI=1.27–3.33), andVUFA(OR=1.90, 95% CI=1.22–2.96) patterns were positivelyassociated with NPC. TheAUFApattern showed a positive association of borderline significance, whereas theVitamins and fibrepattern was nonsignificantly but inversely associated with NPC.Conclusions:These findings suggest that diets rich in animal products, starch, and fats are positively related to NPC risk in thislow-incidence country