中文摘要：

目的研究胸苷酸合成酶（TS）基因5’端非编码区（UTR）多态性与晚期胃癌对氟尿嘧啶（5-FU）化疗敏感性的关系。方法经病理学确诊的晚期胃癌56例，化疗前抽静脉血，提取白细胞DNA，用PCR技术检测TS5＇-UTR基因型。所有患者均经5-FU为基础的化疗方案治疗。以实体瘤疗效评定标准和毒性评定标准评价疗效和毒性。结果56例胃癌患者中，TS5＇-UTR基因型分2R／2R、2R／3R、3R／3R，基因型频率分别为5．4％、42．8％和51．8％，化疗的总有效率为35．7％。2R／2R和2R／3R基因型组（27例）化疗的有效率为55．6％（15／27），明显高于3R／3R基因型组（29例）的17．2％（5／29）（P〈0．01）。2R／2R和2R／3R基因型组Ⅱ度以上毒副反应的发生率略高于3R／3R基因型组。结论TS基因5＇-UTR多态性与晚期胃癌对5-FU为基础的化疗敏感性相关。5f-UTR基因型检测有助于指导晚期胃癌的化疗。

英文摘要：

Objective To investigate the relationship between polymorphism in the 5＇-UTR of thymidylate synthase gene （TS） and sensitivity of stomach cancer （SC） to fluoropymidine （5-FU） - based chemotherapy. Methods A total of 56 cases with advanced SC were treated with 5-FU-based chemotherapy and DNA of peripheral blood leukocytes was obtained before therapy. TS 5＇-UTR genotypes were detected by PCR method. The objective responses and toxicities were evaluated according to RECIST criteria. Results Of all the cases, the frequencies of 5＇-UTR 2R/2R, 2R/3R and 3R/3R genotypes were 5.4%, 42. 8% and 51.8%, respectively. The overall response rate to 5-FU- based chemotherapy was 35.7%. The response rate to therapy in patients with TS 2R/2R and 2R/3R genotypes was significantly higher than that in patients with 3R/3R genotype（55.6% vs. 17.2%） （P〈0. 01）. The incidence rates of the treatment-related more than Ⅱ grade side effect with the 2R/2R and 2R/3R genotype were slightly higher than that of the 3R/3R genotypes. Conclusion The polymorphism of TS 5＇-UTR is associated with clinical response to 5-FU-based chemotherapy, suggesting that TS 5＇-UTR genotypes could identify advanced SC patients that would be responsive to 5-FU-based chemotherapy.