消化道肿瘤的发生率在我国位居第一,而多数患者确诊时即为中晚期,已失去手术的机会,故化疗已成为此类患者的主要治疗手段。虽然以氟尿嘧啶(5-FU)为基础的联合化疗可以延长胃癌、结直肠癌等晚期消化道肿瘤的生存期,但是接受此类方案中至少50%患者对化疗无效[1],而且同一化疗方案 The incidence of gastrointestinal tumors in China ranked first, while the majority of patients diagnosed in the late, has lost the chance of surgery, so chemotherapy has become the main treatment for such patients. Although 5-fluorouracil-based combination chemotherapy can prolong the survival of advanced gastrointestinal cancers such as gastric cancer and colorectal cancer, at least 50% of patients receiving such regimen are refractory to chemotherapy [1], and the same chemotherapy regimen