Synchronous colorectal carcinoma: Clinico-pathological features and prognosis

Objective: The present study was undertaken to clarify the clinical and pathological features of synchronous colorectal carcinomas, to compare prognosis between cases with synchronous carcinomas and those with single carcinomas and to explore prognostic factors of synchronous carcinomas. Patients and methods: Among 876 surgically resected primary colorectal carcinomas, 42 cases (4.8%) with synchronous carcinomas were identified. Clinical characteristics, routine pathological findings according to the TNM classification and postoperative survival were compared between synchronous cases and single cases. Prognostic factors of synchronous cases were explored using the proportional hazard model. Results: The index lesions of synchronous cases did not differ from single lesions in age, size, differentiation, location, pT value, pN value, pathological stage, morphology or lymphatic invasion. However, the male:female ratio was higher and distant metastasis was more frequent in synchronous cases than in single cases. Although postoperative survival of synchronous cases was shorter than that of single cases, they were similar in the multivariate proportional hazard model including pathological stage and curability as co-factors. Only pathological stage and curability of the index lesion were significant co-factors of postoperative survival of synchronous cases. Conclusion: Synchronous carcinomas and single carcinomas were similar in clinical characteristics and routine pathological findings. The prognosis of synchronous cases and that of single cases did not differ if the pathological stages were identical and the resections were curative.