Distribution of integrin cell adhesion molecules in endometrial cancer.

Integrins are ubiquitous cell adhesion molecules that are involved in maintaining normal tissue morphology and have been implicated in the behavior of certain malignancies. We examined the expression of nine integrin subunits in 38 endometrial adenocarcinomas using immunohistochemistry. The pattern of integrin expression in the cancers was compared with that seen in the endometrium of 20 normal cycling women and 7 postmenopausal women. Integrin expression was correlated with grade, stage, nodal status, depth of invasion, steroid receptor status, and histological pattern. In endometrial cancers there was an inverse relationship between the number of integrins expressed and histological grade (P = 0.011). Of the normally expressed, constitutive endometrial epithelial integrin subunits (alpha 2, alpha 3, alpha 6, and beta 4), the least frequently seen in the cancers was the alpha 3 subunit (44.7%) and the most frequently found was alpha 6 (81.6%). The alpha 5 beta 1 integrin, a fibronectin receptor normally found only on endometrial stromal cells, was seen in 17.8% of cases of these epithelial cancers. In addition, a significant association was found between the loss of the alpha 2 beta 1 integrin and the presence of lymph node metastases (P < 0.001). These data suggest that a decline in integrin expression occurs more frequently in poorly differentiated endometrial cancers and that the loss of specific integrins may be associated with metastatic nodal spread.