Carcinoembryonic antigen levels of portal blood in gastric cancer patients

Abstract

Correlation between carcinoembryonic antigen (CEA) levels of peripheral venous and portal blood and six histopathologic and immunohistochemical variables was examined in 53 gastric cancer patients and in 8 patients with benign diseases, in order to clarify the elevation mechanism of CEA in the peripheral blood. Immunohistochemically, CEA was localized in 48 (90.6%) of the 53 cancer lesions. CEA levels of portal blood (with a mean of 136.5 ng/ml and positive rates greater than 5 ng/ml, 58.3%) were significantly higher than those (30.3 ng/ml and 22.9%) of peripheral blood in 48 patients with CEA localized cancer. However, CEA levels of portal blood were as low as 5 ng/ml and were not different from those of peripheral blood in all of the CEA nonlocalized cancer and benign diseases. Elevation of CEA in portal blood and also peripheral blood was most highly correlated with venous invasion, although CEA levels in portal blood were significantly associated with three other variables including tumor size, lymphatic invasion, and node metastasis. These variables relating to CEA elevation in the blood were significantly related to venous invasion, whereas a relationship between venous invasion and tumor differentiation and the CEA distributed pattern was not found. These results suggest that CEA may be mainly drained by the hematogenous portal system via the draining vein from CEA localized cancer cells in the invaded veins of gastric cancer lesions, and, additionally, that histopathologic CEA elevation-relating variables may secondarily affect the CEA elevation in the blood in association with the venous invasion.