Association sf the NAD(P)H : quinone oxidoreductase C-609 -> T polymorphism with a decreased lung cancer risk

The NAD(P)H:quinone oxidoreductase gene, NQO1, often carries a C-->T transi tion at bp 609, which has been associated with a reduced enzymatic activity and which may result in altered metabolic activation of tobacco smoke proc arcinogens. We tested the association of this polymorphism with lung cancer risk in a population-based case-control study of 327 cases and 440 control s of Caucasian, Japanese, or Native Hawaiian ancestry in Hawaii. We found a notable difference in the frequency of the variant allele among Japanese ( 38%), Caucasians (20%), and Hawaiians (22%), Overall, thr: variant allele w as less frequent in cases than in controls (P = 0.03), A significant invers e association was found in Japanese, with adjusted odds ratios of 0.8 (95% confidence interval, 0.4-1.5) and 0.3 (0.1-0.7) for the heterozygous and ho mozygous variant genotypes, respectively, compared with the homozygous wild -type genotype (P for genetic trend, 0.02), The association did not reach s tatistical significance in Caucasians and Hawaiians but Has in the same dir ection.