目的：分析结直肠癌肿瘤最大径最佳截点及其与患者临床病理特点及预后的关系。 方法：选择2006 年1 月—2012 年7 月行结直肠癌根治术与术后行规范化辅助治疗的结直肠癌患者 119 例的临床资料。采用Kaplan-Meier 生存分析方法，筛选结直肠癌肿瘤最大径的最佳截点值；分析 肿瘤最大径与结直肠癌患者临床病理因素的关系，并分析结直肠癌患者预后影响因素。 结果： 以最大径4 cm 为截点， 两侧患者生存率差异最明显（65.5% vs. 51.1%，χ2=9.922， P=0.002），故确定结直肠癌肿瘤最大径最佳截点值为4 cm。肿瘤最大径<4 cm 患者与≥ 4 cm 患者在 肿瘤T 分期、淋巴结检出总数、血清CEA 方面差异有统计学意义（均P<0.05）。单因素分析显示， 肿瘤最大径、T 分期、M 分期、血清CEA 水平、是否输血与结直肠癌预后有关（均P<0.05）；多因 素分析表明，肿瘤最大径、T 分期、是否输血是结直肠癌预后的独立影响因素（均P<0.05）；按肿 瘤最大径分层分析，T 分期是≥ 4 cm 患者预后的独立影响因素（HR=2.244，95% CI=1.079~4.665， P=0.030），但以上因素对肿瘤最大径<4 cm 患者预后影响不明显（均P>0.05）。 结论：肿瘤最大径可作为影响结直肠癌预后的独立影响因素，其最佳截点值为4 cm，参照该截点值， 有助于对患者临床特点及预后作出判断。
Relations of best cut-off value of tumor maximum diameter with clinical features and prognosis of colorectal cancer
Objective: To determine the appropriate cutoff value for tumor maximum diameter of colorectal cancer and its relations with the clinicopathologic characteristics and prognosis of the patients. Methods: To clinical data of 119 patients with colorectal cancer undergoing radical resection followed by standard adjuvant chemotherapy from January 2006 to July 2012 were collected. The best cut-off value for tumor maximum diameter of colorectal cancer was determined by Kaplan-Meier survival analysis, the relations of tumor maximum diameter with clinicopathologic characteristics of the patients were analyzed, and the prognostic factors for colorectal cancer were also analyzed. Results: Using 4 cm as a cut-off point, the difference in survival rate of patients between two sides was most remarkable (65.5% vs. 51.1%, χ2=9.922, P=0.002), so 4 cm was regarded as the best cut-off value for tumor maximum diameter of colorectal cancer. There was significant difference in T classification, total number of lymph node detection, serum CEA level between patients with tumor maximum diameter <4 cm and ≥4 cm (all P<0.05). Univariate analysis showed that tumor maximum diameter, T classification, M stage, serum CEA level, and blood transfusion were related to the prognosis of the patients with colorectal cancer (all P<0.05), and multivariate analysis revealed that tumor maximum diameter, T classification and blood transfusion were independent prognostic factors for colorectal cancer (all P<0.05). Analysis after stratification by tumor size identified that T classification was an independent prognostic factor for colorectal patients with tumor maximum diameter ≥4 cm (HR=2.244, 95% CI=1.079–4.665, P=0.030), but all factors had no significant influence on prognosis of those with tumor maximum diameter <4 cm (all P>0.05). Conclusion: Tumor maximum diameter can be regarded as an independent prognostic factor for colorectal cancer, and the best cut-off value for tumor maximum diameter is 4 cm, which may be helpful for estimating the clinical features and prognosis of the patients.