中文摘要：

多药耐药基因1（MDR1）C3435T多态性影响肿瘤发病风险及疗效.由于T等位基因能够使致癌物质更易在组织中积聚,因此TT基因型患者更易发生乳腺癌、胃癌、结直肠癌.并且C3435TTT基因型与KRAS基因野生型同时存在的患者化疗效果最好.但由于种族不同、地区差异、样本量不同等客观因素存在,C3435T多态性与乳腺癌、胃癌患者化疗效果的关系仍在探索中.

英文摘要：

Multidrug resistance gene MDR1 C3435T polymorphism influences tumor incidence and treatment outcome. Carcinogenic substances are easier to accumulate in tissue for T allele patients, so TT genotype patients are more likely to develop into breast neoplasms, stomach neoplasms and colorectal neoplasms.Besides, the chemotherapy treatment outcome for patients with both C3435T TT genotype and wild-type KRAS is the best. However, due to ethnic, regional and sample differences, the relationship between C3435T polymorphism and stomach neoplasms 、colorectal neoplasms is still unclear.