目的： 分析同时性多原发结肠直肠癌（简称同时性结肠直肠癌，synchronous colorectal carcinoma, SCRC）的发病、诊断与治疗效果，提高对SCRC治疗的认识。方法： 回顾性分析2012年12月至2018年6月瑞金医院外科收治的39例SCRC病人临床资料。对诊断方法、手术方式、术后生存进行分析。结果： 39例SCRC占同期结肠直肠癌的2.84%。男27例，女12例, 年龄（59.46±1.80）岁，低于同期单发结肠直肠癌病人（P<0.001）。SCRC术前肠镜诊断率45.95%，CT诊断率21.21%。有2例SCRC病人术前行PET-CT检查，发现全部病灶。39例病人中，20例病灶位于同一肠段，行标准结肠直肠癌根治术。3例行扩大结肠直肠癌根治术。16例病灶间距较远，其中10例行分段根治切除术，6例行结肠直肠全切除或次全切除术分段根治切除，后者手术时间最长（P=0.008）。不同手术方式病人术中出血量差异无统计学意义（P>0.05），住院时间差异无统计学意义（P>0.05）。采用分段切除与全切除或次全切除病人清扫淋巴结数目较多（P=0.004）。采用全切除或次全切除病人每日排便次数最多（P<0.001）。标准结肠直肠癌根治术病人3年总生存率100.00%，5年总生存率83.33%。采用分段切除及全切除或次全切除病人3年总生存率60.00%，5年总生存率44.44%。结论： SCRC发病率低且易漏诊。内镜联合增强CT或PET-CT检查有利于术前诊断。病灶位于同一肠段，行标准肠癌根治术预后较好。病灶位于间隔肠段，间距较远，预后较差。

Objective: To analyse the incidence, diagnosis and treatment effect of multiple synchronous primary co-lorectal carcinoma(SCRC) to both explore reasonable alternative treatment types and improve the recognition of SCRC. Methods: The clinical data of 39 cases with SCRC admitted to Department of Surgery, Ruijin Hospital from December 2012 to June 2018 were retrospectively. Diagnosis and surgical types with postoperative survival was analysed. Results: There were 39 cases with SCRC, 27 cases male and 12 cases female, accounting for 2.84% of the cases with colorectal cancer in same period. The age (59.46±1.80) years in this study was lower than that of cases with single colorectal cancer in that period (P<0.001). Preoperative diagnosis rate of the cases with SCRC was 45.95% using colonoscopy and 21.21% using CT. Two cases with SCRC were diagnosed preoperatively by PET-CT examination and found all the focuses. In all cases, 20 cases with lesions located in same intestinal segment underwent standard radical resection of colorectal cancer. Extended radical colorectal resection was done for 3 cases. For the other 16 cases with distant lesions, 10 cases underwent segmental radical resection, and 6 cases total or subtotal colorectal resection, which had the longest operative time(P=0.008). There was no difference in intraoperative blood loss of cases (P>0.05) and in hospital stay (P>0.05) among different surgery. The most number of lymph nodes dissected was the cases using segmental resection and total or subtotal resection (P=0.004) and the cases with total or subtotal resection had the most number of defecation per day(P<0.001). The 3-year survival rate of cases with standard radical surgery of colorectal cancer was 100.00%, and the 5-year survival rate 83.33%. For the cases with segmented resection and subtotal or total colorectal resection, the 3-year survival rate was 60.00%, and the 5-year survival rate 44.44%. Conclusions: The incidence of SCRC might be low and would to be missed the diagnosis more. Endoscopy combined with enhanced CT or PET-CT favored the preoperative diagnosis. Standard radical resection of colorectal cancer was done for the lesions in same intestinal segment with better prognosis. The lesions located separately in the segment and far apart had poorer prognosis.