[Meta analysis of 2025 cases with multiple primary colorectal carcinoma]

To summarize the clinicopathological characteristics of multiple primary colorectal carcinoma.

With "multiple primary colorectal carcinoma" as search words,and with the same inclusion and exclusion criteria, related Chinese literatures published were retrieved. A meta analysis was carried out.

The incidence of multiple primary colorectal carcinoma was 2.9%; and the average age was 53 years. 55.2% of the cases with synchronous multiple primary colorectal carcinoma were diagnosed by fiberoptic colonoscopy before operation,37.5% by intraoperative exploration, 15.7% by postoperative pathology. 94.8% of the cases with metachronous multiple primary colorectal carcinoma were diagnosed by fiberoptic colonoscopy before operation,and the average interval was 5.2 years. 30.9% of the lesions were located in the rectum, 19.9% in the sigmoid, 9.0% in the descending colon, 5.2% the in splenic flexure, 9.1% in the transverse colon, 6.1% in the hepatic flexure, 11.8% in the ascending colon,and 8.1% in the caecum. 37.6% of the cases were complicated with extra- intestinal lesions,and 43.7% adenoma or polyps. 34.6% of the cases had lymph node metastasis. Histological type was the same in 60.6% of the cases,and adenocarcinoma accounted for 89.2% and cancerization of adenoma 8.4%. Radical resection was performed in 85.9% and palliative resection in 10.1% of the cases. The 3, 5, 10 and 15 year survival rates were 64.3%, 44.6%, 26.3% or 9.4% in synchronous multiple primary colorectal carcinoma respectively, and 69.6%, 59.2%, 45.0%, 36.7% in metachronous multiple primary colorectal carcinoma.

Multiple primary colorectal carcinoma is rare in clinic. The diagnosis mainly depends on colonoscopy and intra-operative exploration. The resection rate is high and the prognosis is better. The prognosis of metachronous multiple primary carcinoma is better than that of synchronous multiple primary colorectal carcinoma.