[Synchronous and metachronous tumors of the colon and rectum]

Three hundred and seventy-two patients with colorectal tumours treated by curative resection between January 1982 and January 1992 were reviewed in order to determine the role of colonoscopy and the outcome of patients with multiple tumours. Thirty (8.1%) of them with a mean age of 57 (35-79) years (20 males, 10 females) had synchronous (19 cases) or metachronous (11 cases) lesions. Rectum and sigmoid colon were the most frequent site of multiple lesions, accounting for 73% of all lesions. Accurate pre-operative diagnosis was performed in 14 of the 19 patients with synchronous lesions, and in the remaining 5 cases failure to perform an intra-operative colonoscopy was the cause of missing the lesions. Three of them had over-looked lesions on the previous barium enema. Synchronous lesions has the tendency to be less invasive as compared to metachronous ones. Five-year survival rates (Kaplan-Meier method) were 45% and 58% for patients with multiple and single lesions respectively (not significant). For patients with colorectal carcinoma a thorough examination of the whole colon by intra-operative colonoscopy should be accomplished in order to rule out the possibility of associated lesions as well as to decrease the incidence of "early" metachronous lesions.