Modulation of E-cadherin expression and morphological phenotype in the intravascular component of adenocarcinomas.

E-cadherin is a morphoregulatory epithelial cell/cell adhesion molecule whose loss from carcinomas probably contributes to a more invasive tumour phenotype. Employing an immunohistochemical technique on 25 adenocarcinomas (8 from stomach, 10 breast, 7 colon) we compared E-cadherin expression and tumour morphology of carcinoma that had invaded vascular spaces with that of extravascular carcinoma, both in primary tumours and in their lymph node metastases. In 40% of cases either at the primary site, in the lymph node metastasis or at both sites, E-cadherin levels were higher in the often tiny intravascular tumour compartment than in the adjacent and much larger extravascular tumour compartment. In no tumour was the highest area of E-cadherin expression present within the extravascular compartment. Increases in the differentiation and cohesion of intravascular tumour occurred in 16% and 20% of cases, respectively. In 3 of 4 cases showing increased differentiation, but in only 1 of 5 cases showing increased cohesion, these morphological changes were associated with increased intravascular E-cadherin levels.