Epidemiology and Histopathology of Nasopharyngeal Neoplasms in Iran

Abstract

Introduction: This study aimed to study the trend, histologic pattern, geographical distribution, and characteristics of nasopharyngeal carcinoma (NPC) and nasopharyngeal neoplasms (NPN) from 2003 to 2017 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 95% confidence interval (CI). The jump model minimized the interfering effect of INCR transformation.Results: A total of 3653 NPN cases were reported between 2003-2010 and 2014-2017 with a mean age of 49.04 ± 18.31 years and a male to female ratio of 2.15. The age-standardized incidence rate (ASIR) per 100,000 person-years in 2017 was 0.30 and 0.68 for females and males, respectively. Although the ASIR/100,000 of NPN raised from 0.35 to 0.49 during 2003-2017, the trend was constant with a AAPC of -2% (95% CI: -4.8% to 0.9%). The age-specific incidence rate was highest in the older than 70 years-old population (1.56/100,000). NPC formed 77.1% of NPNs and showed a constant pattern (AAPC CI: -5.7% to 0.2%), in contrast to the significant increase of non-keratinizing squamous cell carcinoma (AAPC CI: 2.3% to 24.5%).Conclusions: Nasopharynx cancer is rare in Iran, and NPC incidence remained constant during 2003-2017, 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