CLINICOPATHOLOGICAL STUDY OF MULTIPLE CARCINOMAS OF THE COLON AND RECTUM WITH A FAMILY HISTORY

Recently colorectal carcinomas have been increasingly reported, multiple carcinomas of the colon and rectum are not rare, and the hereditary factor seems to be involved in the etiology of such multiple occurrence. Thirty-seven cases of multiple colorectal cancers experienced at the department in a recent 14-year period were clinicopathologically studied. Of these 37 patients, seven patients (15 lesions) had a family history of colorectal cancer within the first degree relatives (positive group) and the remaining 30 patients (65 lesions) had no family history (negative group). Patients in the positive group were younger than those in the negative group. Carcinomas of the positive group were located in more prpximal colon than those of the negative group. Histological examination revealed that most of the first lesions in the positive group were moderately differentiated adenocarcinomas while the second lesions were commonly well differentiated adenocarcinomas. Presence of associated adenomatous polyps was more common in the negative group than in the single carcinomas. The cumulative 5-year survival rate was 62.5% in the positive group and 42.0% in the negative group. All patients in the positive group satisfied the diagnosis criteria of HNPCC (hereditary nonpolyposis colorectal cancer), but the negative group may include initiator of HNPCC.