Nasopharyngeal carcinoma in Chinese—Salted fish or inhaled smoke?

Abstract

The role of two proposed risk factors for nasopharyngeal carcinoma (NPC) in Chinese was examined by comparing incidence rates (1974–1975) of NPC among Chinese in Hong Kong with those in Los Angeles County (1972–1976) by age, sex, birthplace, and occupation. In Hong Kong, incidence rates for NPC were highest for persons born outside of the Chiu Chau region in Kwangtung Province. In Los Angeles County, the highest rates were observed for immigrant Chinese followed by indigenous Chinese. The high rates in Hong Kong-born Chinese and in Hong Kong boat people and the much higher rates in men compared with women do not support an inhaled carcinogen as the major risk factor for NPC in southern Chinese. The incidence data coupled with available experimental evidence are most consistent with consumption of Cantonese salted fish as the major etiologic factor.