Sensitivity, specificity and prognostic value of CEA in colorectal cancer : Results of a Tunisian series and review of literature

In order to determine the sensitivity of CEA in the diagnosis of colo-rectal carcinoma, we studied a series of 48 patients with colo-rectal carcinoma (1992-1996). The sensitivity was at 52 % with a reference value of 5 ng/ml and 68,7 % for a reference value of 2,5 ng/ml. With a reference value of 5 ng/ml, the sensitivity of CEA was at 37 % only for patients with colo-rectal carcinoma at Dukes B stage, 66,6 % for patients at stage C and 75 % for patients at stage D . The dosage of CEA was carried out with a sandwich immunoenzymatic technique in tube. There is no statistic significant correlation between the pre-operative rate of CEA and the localisation of the tumor and its histologic type ; in contrast, it was significantly correlated with the ganglionnary metastasis. A significant relationship between the pre-operative rate of CEA and the Dukes stage was found for a reference value of 10 ng/ml but not for a reference value of 5 ng/ml. We calculated the-specificity of the CEA for the cancers of colon and rectum wich was at 76,98% with a reference value of 5 ng/ml and 86% with a reference value of 10 ng/ml.