Epidemiology and Histopathology of Nasopharyngeal Neoplasms in Iran

Introduction: This study aimed to study the trend, histologic pattern, geographical distribution, and characteristics of nasopharyngeal carcinoma (NPC) and nasopharyngeal neoplasms (NPN) from ۲۰۰۳ to ۲۰۱۷ in Iran.Material and Methods: The Ministry of Health and Medical Education collected NPN cases from each province's corresponding university and stored them at Iran's National Cancer Registry (INCR) database. The Joinpoint program calculated the average annual percent change (AAPC) and its ۹۵% confidence interval (CI). The jump model minimized the interfering effect of INCR transformation.Results: A total of ۳۶۵۳ NPN cases were reported between ۲۰۰۳-۲۰۱۰ and ۲۰۱۴-۲۰۱۷ with a mean age of ۴۹.۰۴ ± ۱۸.۳۱ years and a male to female ratio of ۲.۱۵. The age-standardized incidence rate (ASIR) per ۱۰۰,۰۰۰ person-years in ۲۰۱۷ was ۰.۳۰ and ۰.۶۸ for females and males, respectively. Although the ASIR/۱۰۰,۰۰۰ of NPN raised from ۰.۳۵ to ۰.۴۹ during ۲۰۰۳-۲۰۱۷, the trend was constant with a AAPC of -۲% (۹۵% CI: -۴.۸% to ۰.۹%). The age-specific incidence rate was highest in the older than ۷۰ years-old population (۱.۵۶/۱۰۰,۰۰۰). NPC formed ۷۷.۱% of NPNs and showed a constant pattern (AAPC CI: -۵.۷% to ۰.۲%), in contrast to the significant increase of non-keratinizing squamous cell carcinoma (AAPC CI: ۲.۳% to ۲۴.۵%).Conclusions: Nasopharynx cancer is rare in Iran, and NPC incidence remained constant during ۲۰۰۳-۲۰۱۷, unlike their rising trend previously reported. However, non-keratinizing squamous cell carcinoma exhibited a significant increase, and future studies are needed to examine the role of the Epstein-Barr virus on this growth rate.

Keywords:

Nasopharyngeal Neoplasms , Nasopharyngeal carcinoma , Epidemiology , Histology , incidence , Iran