Incidence of nasopharyngeal carcinoma in Chinese immigrants, compared with Chinese in China and South East Asia: review.

OBJECTIVES

To evaluate the literature and to compare published data on age-standardised incidence rates of nasopharyngeal carcinoma in Chinese people living in and outside China.

DESIGN

Systematic review of incidence rate studies and statistical incidence data concerning nasopharyngeal carcinoma in Chinese populations from 1960 to 2008.

DATA SOURCES

Sixteen papers were identified from the PubMed, Embase and Scopus electronic databases and from a hand search of the reference lists of the retrieved papers. Further searches for raw data on age-specific and age-standardised incidence rates of nasopharyngeal carcinoma were conducted. Textbooks on relevant subjects were referred to for background information. A total of 19 papers met the inclusion criteria.

RESULTS

Seven studies included raw data on age-specific and age-standardised incidence rates of nasopharyngeal carcinoma in Chinese people. Twelve other studies reported on changes in the incidence of nasopharyngeal carcinoma in Chinese populations in selected countries or regions. Studies on age-specific and age-standardised rates obtained data from individual registries. Studies on incidence rates obtained data from hospital records, cancer notifications (from all sections of the medical profession), pathology records and death certificates. The results showed a decline in age-standardised incidence rates of nasopharyngeal carcinoma in Chinese immigrant populations, compared with Chinese people in China. There was also a trend towards decreasing incidence the further the population had immigrated. Thus, the incidence of nasopharyngeal carcinoma in Singaporean Chinese was higher than that in Hawaiian Chinese, and that in Hawaiian Chinese was higher than that in Californian Chinese.

CONCLUSION

This review found a decreasing trend in the incidence of nasopharyngeal carcinoma in Chinese migrants living in countries with a low risk of the disease.