[Carcinoembryonic antigen (CEA) levels of peripheral and portal blood and tumor histopathology in colorectal cancer].

Correlation between CEA levels of peripheral and portal blood and 9 histopathologic variables were examined in 66 patients with colorectal cancer. CEA levels of portal blood (mean 26.6ng/ml and positive rate more than 5ng/ml, 59.1%) were significantly higher than those (8.1ng/ml and 33.3%) of peripheral blood. Elevation of CEA levels in portal and peripheral blood were most highly correlated with the grade of vein invasion and its location in the layer of colorectal wall, although the levels were related to the other 8 histopathologic variables such as tumor size, the grade of node metastases, Dukes stage and so on. CEA levels of portal blood elevated from 19.4ng/ml and 40% to 43.6ng/ml and 90.2% respectively following operative stimuli to cancer lesions with vein invasion, but the levels did not elevated in the lesions without its invasion. CEA levels of peripheral blood were as low as 5ng/ml in 3 out of 8 patients with liver metastases. However, the levels in portal blood were much higher than 5ng/ml in all the patients. These results suggested that CEA might be hematogenously drained by portal system from cancer cells in the invasive veins, but not by thoracic duct of lymphatic system, and also that the measurement of CEA in portal blood might be available to predict the vein invasion of cancer lesions and liver metastases in patients with colorectal cancer.