Our results indicated that CYP1A1 Ile/Val genetic polymorphisms, but not CYP1A1 Msp I polymorphisms, are associated with an increased digestive tract cancer risk in Chinese population.
A thymine/cytosine point mutation in the MSP I restriction site of cytochrome P450 1A1 (CYP1A1) has been linked to susceptibility to smoking-related cancers and is reported to result in increased enzyme activity.
Further stratification analysis in postmenopausal women who were non-smokers and with no history of hormone replacement therapy showed the cancer risk due to the Msp1 variant to be more significant in women with early menarche.