Increased Risk of Nasopharyngeal Carcinoma with Increasing Levels of Diet-Associated Inflammation in an Italian Case–Control Study

ABSTRACT

Purpose: Components of diet can modulate inflammation and therefore may have an important role in the development of nasopharyngeal carcinoma (NPC). Little is known about the inflammatory potential of diet in relation to nasopharyngeal carcinogenesis. Methods: Data from an Italian multicenter case–control study conducted between 1992 and 2008 and including 198 cases with incident, histologically confirmed NPC, and 594 controls hospitalized for acute nonneoplastic diseases were used to estimate the relation between a dietary inflammatory index (DII) and the risk of NPC. The DII was computed based on the intake of selected dietary factors assessed by a validated 78-item food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) adjusted for study center, place of living, sex, age, year of interview, education, tobacco smoking, alcohol drinking, and energy intake using the residual method. Results: Subjects with higher DII scores had an increased risk of NPC, with each DII point increasing risk by nearly 20% [OR: 1.19; 95% confidence interval (CI): 1.05–1.36]. Compared to subjects in the lowest DII tertile, those in the highest tertile had >60% higher risk of NPC (OR: 1.64; 95% CI: 1.06–2.55; P_trend = 0.04). Conclusion: These results indicate that inflammatory potential of diet plays a role in NPC.

Acknowledgments

This study was supported by the Italian Institute of Health, Italian Ministry of Health, General Directorate of European and International Relations, and the Italian Foundation for Research on Cancer (FIRC). Drs. Shivappa and Hébert were supported by grant number R44DK103377 from the United States National Institute of Diabetes and Digestive and Kidney Diseases.

Author contribution

AZ, MM, CLV, ML, WG, and DS designed and conducted the case–control study; NS conducted the analyses and wrote the first draft of the manuscript; MR, JRH, CLV, and AZ provided suggestions and revised the manuscript. All authors approved the final version of the manuscript.

Disclosure

Dr. James R. Hébert owns controlling interest in Connecting Health Innovations LLC (CHI), a company planning to license the right to his invention of the DII from the University of South Carolina in order to develop computer and smartphone applications for patient counseling and dietary intervention in clinical settings. Dr. Nitin Shivappa is an employee of CHI.