Carcinoembryonic antigen (CEA) in serum and fresh cancer tissue taken at surgery was measured and analyzed in terms of the disease stage. The CEA level in serum (s-CEA ) has become higher with advance in the disease stage. However, in stage V it was lowered as well as CEA level in cancer mass (ca-CEA). It is suggested that S-CEA is influenced by cancer invasion into the vessel wall, tumor necrosis and/or degeneration which ca-CEA may well be migrated from the tumor cells
