ABSTRACT
Objective To summarize the clinicopathological features with 617 cases colorectal cancer and explore reliable clues for early diagnosis. Methods Retrospective analysis of clinical, endoscopic, pathological features and DNA mismatch repair of 617 cases of colorectal cancer was made from January 2008 to March 2017. Results The overall diagnostic yield of colorectal cancer was 2.35% (596/25 308). 18 patients were diagnosed as simultaneous multiple colorectal cancer (3.02%, 18/596). Males and females ratio is 1.34 : 1.00. The average age diagnosed was 66.8 years old. The proportion of colon cancer was 76.68% (457/596), while cancer located in right side of the colon was 39.17%. Occurrence rate of right colonic cancer were higher in female group (47.34%) than that in male group (33.46%) (P = 0.003). Well and moderately differentiated adenocarcinoma was observed in 84.60% (522/617) of the patients. The ratio of mucinous adenocarcinoma was 6.81% (42/617). Totally 230 patients received the DNA mismatch repair, and 57 patients were diagnosed as defective DNA mismatch repair (24.78%). Defective DNA mismatch repair (dMMR) was associated with right colonic cancer, poorly differentiated adenocarcinoma, signet-ring carcinoma and mucinous adenocarcinoma (P < 0.05). Conclusions Colonoscopy screening in the elderly patients deserves great attention. Raise awareness of simultaneous multiple colorectal cancer. Pay attention to the screening of right colon cancer in female. The DNA mismatch repair should be detected in right colonic cancer, poorly differentiated adenocarcinoma, signet-ring carcinoma and mucinous adenocarcinoma.