Objective: To investigate the expression of E-cadherin in human soft tissue sarcomas and its potential relationship to p53 alterations.
Design: Tissue sections of 91 soft tissue sarcomas were analyzed by immunohistochemistry for E-cadherin and p53 proteins. Sixty-one tumors were investigated further by the application of the polymerase chain reaction technique and a direct sequence analysis procedure of exons 5 through 8 in the p53 gene.
Setting: Tertiary-care teaching hospital.
Patients: Ninety-one patients with soft tissue tumor were treated surgically. Thirteen of these patients had tumors with epithelial differentiation.
Results: E-Cadherin was expressed at the cell-cell boundaries in 11 samples (12%): 9/13 (69%) with and 2/78 (3%) without histologic evidence of epithelial elements. Other sarcomas were completely negative for E-cadherin. Overexpression of p53 was detected in 30 cases (33%), 7 of which also demonstrated mutations in the p53 gene. The frequencies of p53 abnormalities in tumors with and without epithelial components were 8% and 37%, respectively. No association was established between E-cadherin immunoreactivity and p53 abnormalities (P =.13). Tumor grade strongly correlated with p53 alterations (P =.01), but not with E-cadherin expression (P =.07).
Conclusions: These data support the involvement of p53 alterations in the pathogenesis of soft tissue sarcomas. The lack of E-cadherin expression in these tumors, with the exception of lesions showing epithelial differentiation, indicates that E-cadherin is not an important factor involved in cell-cell adhesion in sarcomas. It is, however, suggested that E-cadherin may play a role in the development and/or maintenance of epithelial architecture in sarcomas, regardless of p53 status.