Cytochrome P450 2A6 polymorphism in nasopharyngeal carcinoma.

Nitrosamine has been identified as a carcinogen for nasopharyngeal carcinoma (NPC). Here, we investigated if a nitrosamine metabolizing gene, cytochrome P450 2A6 (CYP2A6) played an important role in NPC development. Relationships between the disease and the CYP2A6 were studied in 74 NPC patients and 137 age-matched healthy controls by using PCR-RFLP assay to distinguish between a wide type allele, *1A, and two mutant alleles, *1B and *4C. Overall, a significant association between CYP2A6 polymorphism and NPC development was observed (P<0.05). Individual with mutant alleles had an increased risk for NPC when compared to those with *1A/*1A (OR=2.37, 95% CI=1.27-4.46). In addition, males who carried mutant alleles of CYP2A6 had a fivefold increased risk for NPC when compared with those who carried *1A/*1A genotype (OR=5.02, 95% CI=1.82-14.14). It is thus suggested that CYP2A6 polymorphism may play a crucial role in NPC susceptibility and it may be used as a risk marker for NPC.