中文摘要：

目的探讨细胞色素P4501A1（CYP1A1）基因Ile462Val单核苷酸多态与小细胞肺癌遗传易感性的相关关系。方法收集275例小细胞肺癌患者和406例正常对照者的外周静脉血标本，采用聚合酶链反应一限制性片断长度多态性分析（PCR．RFLP）技术检测CYP1A1基因Ile462Val多态的基因型。采用多变量Logistic回归方法分析不同基因型与小细胞肺癌发病风险的相关关系。结果与CYP1A1462Ile／Ile基因型携带者相比，462Ⅱe／Val和462Val／Val基因型携带者小细胞肺癌发病风险显著降低，其OR值分别为0．65（95％C10．48～0．91）和0．60（95％C，0．32～0．97）。吸烟分层分析显示，在不吸烟人群中，462Ile／Val或462Va1／Va1基因型携带者小细胞肺癌发病风险的OR值为0．99（95％c，0．62～1．51）。在吸烟人群中，462Ile／Val或462Val／Val基因型携带者小细胞肺癌发病风险的OR值为0．42（95％CI，0．26～0．65）。此外，在轻度吸烟者和重度吸烟者中462Ile／Val或462Val／Val基因型携带者小细胞肺癌发病风险的OR值分别为0．42（95％C，0．21～0．85）和0．44（95％c，0．24～0．82）。结论CYPlAl基因Ile462Val多态与小细胞肺癌遗传易感性相关。

英文摘要：

Objective To investigate the association of Ile462Val polymorphisms of cytochrome P450 1A1 （CYP1A1） gene with small cell lung cancer susceptibility. Methods A case-control study was clone in 275 patients with small cell lung cancer and 406 control subjects. Genotypes of CYP1A1 Ile462Val were determined by polymerase chain reaction- based restriction fragment length polymorphism （PCR-RFLP）. Logistic regression analysis was performed to estimate odd ratios （ORs） and 95% confidence intervals （95% CI） associated with genetic variants of CYP1A1. Results A case-control analysis showed ORs of 0. 65（95% CI 0. 48 -0. 91 ） and 0. 60 （95% CI 0. 32 -0. 97） for small cell lung cancer in the CYP1A1 462 Ile/Val and 462 Val/Val genotype carriers respectively, compared with 462 Ile/Ile carriers. When stratified by smoking status, the ORs of 462 Ile/Val or Val/Val genotype for nonsmokers and smokers were 0. 99 （95% CIO. 62 -1.51） and 0. 42 （95% CI 0. 26 - 0. 65）, respectively. Furthermore, for light and heavy smokers, the ORs of 462 Ile/ Val or Val/Val genotype were 0. 42 （95% CI 0. 21 - 0. 85 ） and 0. 44 （95% CI O. 24 - 0. 82）, respectively. Conclusion CYP1A1 Ile462Val polymorphisms may contribute to the decreased susceptibility of small cell lung cancer.