Abstract: Objective To study the diagnosis, clinicopathological features, treatment, and prognosis of synchronous colorectal cancer (SCRC).Methods The clinical data and pathological features of the patients with SCRC admitted to Beijing Friendship Hospital, Capital Medical University from January 2008 to December 2016 were retrospectively analyzed.Results According to the inclusion criteria, 35 cases with SCRC were enrolled. Of which, Thirty-four cases were double primary carcinoma and one was triple primary carcinoma. 34 cases were first diagnosed and one was second diagnosed on three months after surgery. The detection rate of barium enema examination and colonoscopy was 60.9% and 70%, respectively while combination of colonoscopy and multiple imaging techniques increased the rate to 91.4%. Pathological analysis of the 71 tumor lesions suggested that adenocarcinoma accounted for 70.4% (50/71) and low/middle differentiated adenocarcinoma accounted for 54.9% (39/71). Thirty-two cases were treated with surgery, of which, 5 cases were treated with standard radical resection, 10 cases with extensive radical resection, 10 cases with regional radical resection, and 7 cases with total/subtotal colectomy. The postoperative 5 year survival rate was 59.4% and recurrence rate was 28.1%.Conclusion SCRC was mostly double primary carcinoma with adenocarcinoma as the dominative pathological type. Combining the results of multiple imaging examinations and colonoscopy may increase the detection rate of SCRC. Choosing appropriate surgical methods according to the specific situations of SCRC may improve the therapeutic efficacy of the patients.

Key words: synchronous colorectal cancer, diagnosis, pathological features, surgical therapy, prognosis