Altered CD44 variant 6 expression in FIGO stage IB cervical carcinoma

CD44 is an adhesion molecule which plays an important role in metastatic cascade by mediating tumor cell interaction with the endothelium and the subendothelial matrix. In this study CD44v6 expression was immunohistochemically investigated on 88 uterine cervical cancers. Correlation between expression and prognostic variables and the survival was examined.

Eighty-eight patients with stage IB disease, treated primarily with surgery, were examined histopathologically and immunohistochemically. CD44v6 expressions of tumoral tissue and the nonneoplastic tissue nearby were examined using antiCD44v6 monoclonal antibody. CD44v6 expression was compared to the known clinicopathologic prognostic variables and survival of patients.

Nonneoplastic epithelium of the sections showed CD44v6 expression predominantly in basal and parabasal layers at least in traces. CD44v6 overexpression in neoplastic islands was evaluated as "general," "basal" (only in the basal portion of neoplastic islands), and "nonbasal" (also in the central portion of the neoplastic islands) separately. When expression and prognostic variables were compared, CD44v6 non-basal expression was found to be significant in nonsquamous cancers, when the tumor diameter was greater than 3 cm and in the tumors that showed recurrences. Univariate survival analysis with the Kaplan-Meier method showed that only the age of the patient is significantly correlated with disease-free survival. Interestingly when the same analysis was done for 5-year overall survival, diameter of the primary tumor, depth of cervical stromal invasion, existence and number of lymph node involvement, positivity for general CD44v6 expression, and positivity for nonbasal expression were found to be statistically significant. Furthermore multivariate analysis with Cox regression showed that nonbasal CD44v6 expression and lymph node involvement are independent variables for 5-year overall survival.

These results indicate that CD44v6 expression is associated with some of the important clinicopathologic prognostic variables and appears to be a predictor of advanced pathological-surgical stage of early clinical stage cervical carcinoma. CD44v6 nonbasal expression is significantly correlated with overall survival.