NQO1 609C > T polymorphism interaction with tobacco smoking and alcohol drinking increases colorectal cancer risk in a Chinese population

• The NQO1 609C > T polymorphism may result in altered metabolic activation of procarcinogens in the environment.
• The contribution of the 609C > T polymorphism to colorectal cancer susceptibility in the Chinese population is unknown.
• The 609 T allele had an elevated risk for developing colorectal cancer.
• The 609C > T polymorphism appeared to have a joint effect with both tobacco smoking and alcoholic drinking.

BackgroundNAD (P)H:quinone oxidoreductase (NQO1) catalyzes the activation of some environmental procarcinogens present in tobacco smoke or the diet. We conducted a hospital-based case–control study to evaluate the potential association between NQO1 609C > T polymorphisms and colorectal cancer risk in a Chinese population.MethodsThe study population comprised 672 histologically confirmed colorectal cancer patients and 672 frequency-matched control subjects without cancer or systemic illness. We used PCR restriction fragment length polymorphism-based methods for genotyping analyses and unconditional logistic regression model for statistical evaluations.ResultsThe risk of colorectal cancer increased with the level of smoking and decreased with the consumption of tea, fresh fruits, and vegetables. In addition, we found that the NQO1 609 CT and TT genotypes were associated with an increased risk of colorectal cancer (CT: adjusted OR = 2.02, 95% CI = 1.55–2.57; TT: adjusted OR = 2.51, 95% CI = 1.82–3.47), compared with the CC genotype. Moreover, NQO1 609C > T appeared to have a multiplicative joint effect with both tobacco smoking and alcoholic drinking (P for multiplicative interactions were 0.0001 and 0.013, respectively) on colorectal cancer risk.ConclusionOur findings suggest that the NQO1 609C > T polymorphism plays an important role in the development of colorectal cancer in the Chinese population, which is strengthened by alcohol drinking or tobacco smoking.