[Multiple primary carcinomas of the colon and associated extracolonic primary malignant tumors].

Adenocarcinoma of the colon is the most common visceral cancer. The incidence of multiple primary colorectal carcinoma varies from 0.6% to 7.6%. A review of 837 cases of colorectal carcinoma showed 32 cases (3.8%) of colorectal multiple primary malignant tumors and 11 cases (1.3%) of colorectal primary malignant tumor associated with extracolonic primary malignant tumor. A total of 78 tumors were involved: 24 in the sigmoid, 12 transverse colon; four in the cecum; 30 in the rectum; 3 in the ascending and 5 in descending colon; 2 each in the bladder, prostate; two each in the breast, cervix, and one each in the skin, nasopharynx, lungs. If synchronous carcinomas are located in the same anatomic region, a conventional resection should be performed. When the carcinomas are widely separated, a subtotal colectomy is the operation of choice. Survival of patients with synchronous carcinomas is not significantly different from survival of patients with same-stage solitary carcinomas.