摘要：

【Objectives】 To investigate the feasibility, safety, and efficacy of preoperative chemotherapy of OxMdG for colon cancer and try to define the best primary intention-to-treat strategy in patients undergoing either preoperative chemotherapy or resection for colon cancer. 【Methods】 From May 2008 to September2010, 100 patients with radiologically staged locally advanced were finally recruited and randomly assigned to preoperative(three cycles of OxMdG repeated at 2 weekly intervals followed by surgery and a further ninecycles of OxMdG) or standard postoperative chemotherapy(12 cycles of OxMdG). The KRAS genotype of all patients were tested, of whom with wild-type tumors were randomly assigned(1:1) to receive Panitumumab(6mg/kg; every 2 weeks with the first 6 weeks of chemotherapy) or not. Treatment allocation was through outpatient electronic medical record using a minimized randomization procedure including age, radiological T and N stage, site of tumor, and presence of defunctioning colostomy as stratification variables. The feasibility, safety,and tolerance of preoperative therapy, and accuracy of radiological staging were analyzed. Analysis was by intention to treat. 【Results】 51 of 52 patients in group C were treated as planned. 1 case was subjected to immediate surgery because of local perforation diagnosis. 92.2%(47/51) patients complete 6 weeks of treatment and 4 cases with severe toxicity dropped out. All patients received surgical resection. Group S of 48cases of patients started and 93.0%(40/43) completed six weeks chemotherapy with hand and foot syndrome in 3 patients. CT examination can accurately determine invasion beyond the muscularis propria and detection of lymph node metastasis. Group S patients have longer operation time than group C(206.0 ± 22.1 vs 165.0 ±11.2, P =0.062), but no significant differences in postoperative morbidity was observed between the preoperative and control groups(P =0.089). The incidence of anastomotic fistula was also shown no significant difference(P =0.158). Patients with lymph node positive in group C were more than group S(38.4%(20/52) vs64.6%(31/48), P =0.009) by postoperative pathological diagnosis. Using T stage to drop period evaluation,group C and group S pathology diagnosis T staging appeared significant difference. Group C had T3or less advanced tumors confirmed at post-resection pathology compared with group S(P =0.10). Preoperative therapy resulted in significant down-staging 38.5%(20/52) in group C including two pathological complete responses,without CT imaging staging. Tumor infiltration depth beyond muscularis propria(10.7 ± 2.1 vs 6.3 ± 1.4; P =0.0022) and tumor maximum vertical diameter(68.7 ± 5.7 vs 43.2 ± 6.8, P =0.0018) are lower after preoperative chemotherapy. 【Conclusion】 Preoperative chemotherapy for radiologically staged, locally advanced operable primary colon cancer is feasible with acceptable toxicity, perioperative morbidity and tumor response.

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