Carcinoembryonic antigen and carbohydrate antigen 19‐9 levels of peripheral and draining venous blood in colorectal cancer patients correlation with histopathologic and immunohistochemical variables

Correlation between carcinoembryonic antigen(CEA) and carbohydrate antigen(CA) 19‐9 levels of peripheral and draining venous blood, and 11 histopathologic and immunohistochemical variables was examined in 83 patients with colorectal cancer. CEA levels of draining blood (mean 34.5 ng/ml and positive rate greater than 5 ng/ml, 60.2%) were significantly higher than those (13.0 ng/ml and 28.9%) of peripheral blood. However, CA19‐9 levels (mean 576.1 U/ml and positive rate greater than 37 U/ml, 29.5%) of draining blood were not different from those (568.0 U/ml and 29.5%) of peripheral blood. Immunohistochemically, CEA was observed in all of the 83 specimens and distributed in most of all cancer cells, whereas CA19‐9 was found in 52(62.5%) of the 83 specimens and sporadically distributed in some parts of cancer lesions in general. Elevation of CEA levels in draining and peripheral blood was most highly correlated with venous invasion, although the levels were related to four other histopathologic variables including liver metastasis, invasive layer of colorectal wall, lymphatic invasion, and Dukes' classification. Significant correlation between the CEA localized pattern of cancer cells was not found. Patients with CA19‐9 nonlocalized cancer showed no elevation of the antigen levels in both peripheral and draining blood. The elevation of CA19‐9 levels in peripheral blood of patients with CA19‐9 localized cancer was most highly associated with lymphatic invasion, although the levels were correlated with five other variables consisting of liver metastasis, tumor differentiation, invasive layer of colorectal wall, venous invasion, and Dukes' classification out of 11 histopathologic and immunohistochemical variables. CEA levels of draining blood rose from 18.2 ng/ml and 40.3% to 30.1 ng/ml and 72.6%, respectively, after operative stimuli to cancer lesions, whereas the change of CA19‐9 levels in draining blood of patients with CA19‐9 localized cancer was not found during the time of operation. These results suggest that CEA may be drained mainly by the hematogenous portal system by the draining vein from the cancer cells in the invasive veins and that CA19‐9 may be drained by the thoracic duct of the lymphatic system. It is also suggested that the CEA and CA19‐9 elevation‐relating variables may secondarily affect the CEA and CA19‐9 elevation in the blood in association with the venous and lymphatic invasion of cancer lesions, respectively.