[Does an obturation in colorectal cancer also modify the behavior of the serum CEA level?].

The CEA-plasma level was determined in 10 patients with malignant obstruction of the large intestine and in 6 patients with benign obstruction of the small intestine. The plasma carcinoembryonic antigen levels were obtained prior to initiating of the treatment and sequentially after treating the complete obstruction. Elevated plasma carcinoembryonic antigen levels are related to the carcinoembryonic antigen production by the primary tumour and not additionally to the obstruction. An elevated plasma CEA level in patients with benign obstruction could not be detected. After relief of obstruction, significant changes in the mean carcinoembryonic antigen values could not be observed.