Variations in nasopharyngeal cancer incidence among specific Chinese communities (dialect groups) in Singapore.

A total of 729 cases of NPC (93.6% confirmed histologically) were diagnosed among the Singapore Chinese population during a five-year period (1968--1972). Age-standardized incidence rates for the total Chinese population were 18.4 per 100,000 per year for males and 7.0 for females; the respective rates for the specific Chinese communities were 14.1 and 4.7 for Hokkien, 18.3 and 6.2 for Teochew, 29.1 and 11.0 for Cantonese, 14.2 and 3.3 for Hainanese, 12.6 and 4.8 for Hakka and 12.2 and 6.0 for the other dialect groups. It is evident that all of the Chinese communities in Singapore have high risks for NPC; only the Cantonese have risks significantly higher than that for the rest of the Chinese population. NPC incidence rates for males and females of the other major racial groups in Singapore were 4.7 and 0.6 for Malays and 0.9 and 0.0 for Indians, respectively.