[Diagnostic value of the assay of beta 2 microglobulin during the monitoring of surgically-treated colorectal cancers. Comparison with carcinoembryonic antigen].

This work presents an evaluation of the diagnostic value of seric beta 2-microglobulin in the follow-up of operated colorectal cancers. Ninety-one patients were operated on with a curative intent between 1976 and 1979. These patients were followed for at least 2 years and divided in 2 groups: a) group NR: 48 patients apparently free of loco-regional recurrence and of distant metastases, b) group R: 43 patients presenting a cancerous relapse. High levels of beta 2-microglobulin were found in 21 patients of group NR (specificity: 56 p. 100) and in 25 patients of group R (sensitivity: 58 p. 100). In the same population, the specificity and the sensitivity of carcinoembryonic antigen (CEA) for the diagnosis of a relapse were 92 p. 100 and 88 p. 100 respectively. No significant statistical correlation was observed between the levels of beta 2-microglobulin and CEA. The sensitivity of the association beta 2-microglobulin + CEA was not superior to the dosage of CEA alone despite its reduced specificity (54 p. 100). These results indicate that the diagnostic value of the dosage of beta 2-microglobulin is inferior to that of CEA and is without interest for the detection of tumoral recurrence in the postoperative follow-up of colorectal cancers.