Cancer of the colon and rectum: A study of the routes of metastases

Abstract

In twenty-eight patients with surgically “curable” carcinomas of the colon, tumor cells were identified in the peripheral blood in 12.5 per cent of the patients and in the regional blood of 36 per cent of the patients. There may be a slight increase in the occurrence of tumor cells in the peritoneal cavity and serosal invasion by the tumor in the patients with tumor cells in the blood. No relationship was apparent to blood vessel invasion, invasion of adjacent tissues, metastases to lymph nodes or ascites and tumor implants. Tumor cells were identified in the peripheral blood of 6.6 per cent of sixty-five patients with surgically “curable” rectal cancer, and in the regional blood of 14 per cent of these patients. The finding of tumor cells in the peritoneal cavity was associated with serosal invasion by the tumor, but no relationship was apparent between the occurrence of tumor cells in the blood and the finding of tumor cells in the peritoneal cavity, serosal invasion, blood vessel invasion, invasion of adjacent tissues, lymph node metastases or the presence of ascites or tumor implants. The lymph from the thoracic duct does not appear to be an important route for the spread of tumor cells from colon or rectal cancer, and the occurrence of pulmonary metastasis may indicate vascular rather than lymphatic spread. It appears that each route of dissemination of cancer cells in patients with colon or rectal carcinoma is relatively independent of other factors, and must be considered separately in any surgical efforts to control the disease.