CEA has been involved in vitro in adhesion mechanisms, but little is known about the function of this glycoprotein in vivo in normal tissue differentiation and malignancy.
In respect to the staining of (sialyl Lex) at focal dedifferentiation, it was positive in 17 of 24 cases (71%) in Group A, in 4 of 24 cases (17%) in Group B and in 11 of 20 cases (55%) in Group C. Focal dedifferentiation and sialyl Lex staining in the primary cancer showed a significant difference between Groups A and B. Sialyl Lex staining at focal dedifferentiation showed a significant difference between Groups A and B and Groups B and C. Other adhesion related molecules, sialyl LeA and CEA, showed no difference among Groups A, B, and C.
CEA mRNA expression in the non-carcinomatous parenchymal tissue and cancer tissue was evaluated by in situ hybridisation using CEA specific riboprobe and was semiquantitated by counting the number of silver grains per cell.