Fiber Intake and Risk of Nasopharyngeal Carcinoma: A Case-Control Study

Abstract

Some studies examined the inverse relation between nasopharyngeal carcinoma (NPC) risk and dietary fibers in endemic populations. By means of a hospital-based case-control study, we verified whether this association was also present in Italy in connection with various types of dietary fibers. Cases were 198 patients with incident, histologically confirmed, NPC admitted to major teaching and general hospitals during 1992–2008. Controls were 594 patients admitted for acute, nonneoplastic conditions to the same hospital network of cases. Information was elicited using a validated food frequency questionnaire including 78 foods, food groups, or dishes. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated for quartiles of intake of different types of fiber after allowance for energy intake and other potential confounding factors. Total fiber intake was inversely related to risk of NPC (OR = 0.58 for the highest vs. the lowest quartile of intake; 95% CI: 0.34–0.96). We found an inverse association for total soluble (OR = 0.58; 95% CI: 0.35–0.96) and total insoluble fiber (OR = 0.56; 95% CI: 0.33–0.95), in particular cellulose (OR = 0.57; 95% CI: 0.33–0.96), and lignin (OR = 0.51; 95% CI: 0.31–0.85). In conclusion, this study suggests that dietary intake of soluble and insoluble fibers is inversely related to NPC risk in a nonendemic southern population.

ACKNOWLEDGMENTS

This work was supported by the Italian Association for Research on Cancer and by Ricerca Corrente IRCSS Centro di Riferimento Oncologico di Aviano. The authors wish to thank Mrs. Maria Olinda Volpato and Maria Grimaldi for study coordination, and Luigina Mei for editorial assistance. We are also deeply grateful to Dr. Emilia De Santis for the revision of histopathological diagnoses; Dr. Maria Parpinel for nutrients ascertainment; Drs. Maurizio Montella (Unit of Epidemiology, Istituto Tumori ‘‘Fondazione Pascale’’, Naples, Italy), Massimo Libra (Department of Biomedical Sciences, Università di Catania, Catania, Italy), and Emanuela Vaccher (Medical Oncology A Div., Centro di Riferimento Oncologico, Aviano, Italy) for cases ascertainment; Drs. G. Chiara (1st General Surgery Department, General Hospital, Pordenone, Italy), G. Tosolini (2nd General Surgery Department, General Hospital, Pordenone, Italy), L. Forner (Eye Diseases Department, General Hospital, Pordenone, Italy), A. Mele (Hand Surgery and Microsurgery Department, General Hospital, Pordenone, Italy), and E. Trevisanutto (Dermatology Department, General Hospital, Pordenone, Italy) for helping in the enrolment of controls.