Carcinoembryonic antigen (CEA). A prospective clinical trail in patients with gastrointestinal cancer

Tests for circulating carcinoembryonic antigen, CEA, in plasma were performed in 29 patients with colonic and rectal cancer, 37 patients with stomach cancer, and in 100 blood donors. Using 5.0 ng per ml as cut off, 48 per cent of the patients with colonic and rectal cancer and 32 per cent of the patients with stomach cancer had elevated CEA-values. The CEA-values could be correlated to the classification of tumours according to Dukes, with significantly elevated values in groups Dukes C and D. The test could reveal 39 per cent of the cases with operable colonic and rectal cancer and 26 per cent of the operable cases of stomach cancer. Five patients with colonic and rectal cancer, and 0 patients with stomach cancer fulfilled the requirements for monitoring. After periods of observation of up to 14 months, definite connection between CEA-values and clinical course could be demonstrated in 1/26 patients submitted to macroscopically radical operation. In 2/7 patients with stomach cancer the CEA-values were entirely misleading. It is concluded that the CEA-test in its present form cannot be recommended for routine employment in patients with gastrointestinal cancer.