Third Epidemiological Analysis of Nasopharyngeal Carcinoma in the Central Region of Japan from 2006 to 2015.

Masafumi Kanno,Hiroyuki Tsuji,Chiyoko Makita,Takanori Wakaoka,Takuma Matoba,Hiromasa Takakura,Kunihiro Nishimura,Takeshi Kodaira,Yuichiro Sato,Shigeharu Fujieda,Yuzo Shimode,Ryosuke Kito,Naohiro Wakisaka,Tomokazu Yoshizaki,Norihiko Narita,Hajime Ishinaga,Keisuke Yamazaki,Seiji Hosokawa,Yasushi Fujimoto

doi:10.3390/cancers11081180

Abstract

The present study aimed to clarify the incidence and clinical outcomes of nasopharyngeal carcinoma (NPC) in the Chubu region of Japan from 2006 to 2015, compared with previous reports. A retrospective analysis was conducted based on medical records from 40 hospitals located in the Chubu region in the central Japanese main island, with a population of around 22.66 million individuals. This study was designed in line with to two previous clinical studies into NPC conducted in the same area of Japan. We recruited NPC patients diagnosed in hospitals across this area over a 10-year period (2006–2015) using a questionnaire about sex, age, primary site, clinical symptoms, pathology, Union for International Cancer Control (UICC) staging, serological exam, treatment, and survival. A total of 620 NPC patients were identified. The age-standardized incidence of NPC from 2006 to 2015 was 0.27 per 100,000 individuals per year. There were no significant differences between this study and the previous two studies conducted in the same area of Japan. The five-year overall survival rate for all patients was 75.9%, while those for patients with stages I, II, III, and IVA were 97%, 91%, 79%, and 68%, respectively. The age-standardized annual incidence of NPC in the present study was 0.27 per 100,000 individuals per year, which was relatively low and stable. The five-year overall survival rate for all NPC patients was significantly improved in this decade compared with previous studies. The smoking rates in male and female NPC patients were 64.5% and 18.8%, respectively, thereby suggesting the involvement of smoking in the incidence of NPC.

Highlights

Nasopharyngeal carcinoma (NPC), predominantly associated with Epstein-Barr virus (EBV), is characterized by remarkable geographical and racial differences in its incidence
A total of 620 patients were diagnosed with nasopharyngeal carcinoma (NPC) in the 10 years from 2006 to 2015 in the Chubu region
Some were excluded due to insufficient follow-up and lack of records, and a final total of 583 patients were included in the analysis

Summary

Introduction

Nasopharyngeal carcinoma (NPC), predominantly associated with Epstein-Barr virus (EBV), is characterized by remarkable geographical and racial differences in its incidence. In Asia, NPC is primarily seen in the middle-aged population, a high proportion of cases in Africa occur in children. A vast majority of NPC cases are squamous cell carcinomas (SCCs) showing different degrees of differentiation. They can be classified into three categories based on the World Health Organization (WHO) classification: type 1 is keratinizing SCC; type 2A is differentiated non-keratinizing SCC; type 2B is undifferentiated non-keratinizing SCC, known as lymphoepithelioma, which is the most common and is most associated with EBV infection; and type 3 is basaloid SCC, which is rare. Distant metastases and recurrence occur frequently in NPC after treatment [8,9]

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Conclusion