Intake of Cantonese-style salted fish as a cause of nasopharyngeal carcinoma.

Ho (1971) of Hong Kong first proposed consumption of Cantonese-style salted fish, a traditional food among southern Chinese, as a possible risk factor for nasopharyngeal carcinoma (NPC) in this high-risk population. Four case-control studies have examined Ho's hypothesis; all results are supportive. The most convincing evidence of a causal association between intake of salted fish and NPC derives from a recent case-control study of young Hong Kong Chinese. It is estimated that over 90% of NPC cases under age 35 in Hong Kong are due to intake of this food during childhood. Preliminary experimental data on Cantonese-style salted fish indicate that N-nitroso compounds may be involved in the carcinogenicity of this human food.