Polymorphisms in drug-metabolizing enzymes as modifiers of cancer risk.

The identification of low-penetrance genes, the polymorphisms of which increase an individual's risk of developing cancer, are likely to be extremely important in the general population. In this report we analyzed two genes involved in detoxification. In a number of loci, we identified polymorphic variation correlating with the expression of the gene product. We analyzed two such loci, the cytochrome P-450 gene CYP2D6 and the N-acetyltransferase 2 (NAT2) genes, in patients with bladder and colon cancer, respectively. We observed no statistically significant associations between the control and cancer populations; however, there was a small increase in heterozygote number in bladder cancer.