CLINICOPATHOLOGICAL STUDY OF COLORECTAL CANCER

During a 15-year period until 1988, we experienced a total of 28 cases of multiple cancer of the colon, consisting of 19 of synchronous and 9 of metachronous. These cases were clinicopathologically studied. Multiple cancers complicated by adenoma with higher rates, 36.8% in synchronous and 55.5% in metachronous cancers, compared to solitary ones (17.%). Although the secondary cancers in the synchronous type were mostly in the early stages, those in the metachronous type were mostly in the advanced stage. The CEA titers of all the secondary cancers in the metachronous type were within normal limit, and 7 among 9 secondary cancers appeared in the oral side of the primary ones. Only 9 of the 19 synchronous multiple cancers had been already diagnosed as multiple preoperatively. In only 4 of the 9 metachronous cancers, the total colon had been examined throughly before the operation for the primary cancer. In cases where the total colon could not be examined preoperatively, we emphasize the necessity of intraoperative colonoscopy in order to detect possible secondary cancer and adenoma. In addition, postoperative periodioal follow-up should be lacked for early detection of a secondary metachronous cancer.