E-cadherin, CD44 and CD44v6 in squamous intraepithelial lesions and invasive carcinomas of the uterine cervix: an immunohistochemical study

OBJECTIVE

To evaluate the immunoexpression pattern of E-cadherin, CD44std and the variant isoform v6 in normal squamous epithelium, low and high squamous intraepithelial lesions (SILs) and invasive squamous cell carcinomas (ISCCs) of the uterine cervix. The purpose was to determine whether any distinctive change in antigenic expression could contribute to the recognition of the earliest commitment to neoplasia and/or the onset of the invasive phenotype.

METHODS

Immunohistochemistry using the avidin-biotin indirect immunoperoxidase method was used to study the protein expression of epithelial cadherin (E-cadherin), cluster differentiation 44 (CD44), and the isoform v6 (CD44v6) in 124 human cervical samples (5 normal, 39 low-grade, 54 high-grade and 26 ISCCS) in formalin-fixed, paraffin-embedded tissue blocks.

RESULTS

Membranous expression of E-cadherin, CD44 and CD44v6 was preserved in normal squamous epithelium and in low-grade squamous intraepithelial lesions. A significant association was observed with the histological grade of the SILs and the immunoreactivity (membranous versus cytoplasmic) pattern of E-cadherin (p < 0.001), CD44std (p = 0.027) and CD44v6 (p < 0.001). A loss of membranous staining and a progressive increase in cytoplasmic staining was observed from low to high grade SILs to ISCCs.

CONCLUSIONS

Our study demonstrates that during the development of cervical lesions substantial qualitative (subcellular localization-membrane to cytoplasmic) and quantitative alterations (changes in expression) occur in the protein expression of E-cadherin, CD44, and CD44v6 in cervical cancer. The most striking observation was the decrease in membranous immunoreactivity and the progressive increase in cytoplasmic staining of E-cadherin, CD44 and CD44v6, relating to loss of differentiation as a consequence of neoplastic transformation.

Biological relevance of E-cadherin-catenin complex proteins in primary epithelial ovarian tumours

This study analysed the biological relevance of E-cadherin, alpha-catenin, beta-catenin and gamma-catenin immunoexpression pattern (reduced vs. preserved phenotype) in epithelial ovarian tumours. Immunohistochemistry was used to evaluate the expression of these proteins in 154 epithelial ovarian tumours, consisting of 17 benign, 33 borderline and 104 malignant tumours. In borderline tumours, the immunoexpression pattern of E-cadherin (p = 0.014) and alpha-catenin (p = 0.030) associated with histological type. In malignant tumours, the immunoexpression pattern of E-cadherin was related with histological type (p = 0.001). The immunoexpression pattern of beta-catenin associated with histological type and tumour differentiation (p = 0.005, p = 0.025, respectively). The preserved phenotype of E-cadherin was most frequently observed in mucinous tumours, whereas reduced E-cadherin was most frequently observed in serous tumours. The preserved phenotype of beta-catenin associated with endometrioid carcinomas, while reduced beta-catenin associated with poorly differentiated serous and clear cell carcinomas. Although the reduced phenotype was the most frequent immunoexpression observed for all proteins of the E-cadherin-catenin complex in epithelial ovarian tumours, only beta-catenin showed a significant difference between benign, borderline and malignant tumours (p = 0.045), since borderline and malignant tumours most frequently showed the reduced phenotype. The immunohistochemical profile of beta-catenin was shown to be of biological relevance: reduced beta-catenin was correlated with loss of tumour differentiation and serous carcinomas that are known to depict aggressive biological behaviour in epithelial ovarian tumours.

Prognostic value of E-cadherin immunoexpression in patients with primary ovarian carcinomas

PURPOSE

To analyse the negative versus positive immunoexpression of E-cadherin in patients with primary ovarian carcinomas, and determine its significance in relation to clinicopathological features, overall and recurrence-free survival (RFS).

PATIENTS AND METHODS

The protein expression of E-cadherin was immunohistochemically evaluated in formalin-fixed, paraffin-embedded samples in 104 patients with primary ovarian carcinomas. The clinicopathological factors studied were age, FIGO staging, histological type, tumour differentiation, the appearance of the ovarian capsule, peritoneal implants and residual tumour after cytoreductive surgery. Overall survival and RFS were evaluated using the Kaplan-Meier method, and multivariate analysis was completed using the Cox regression model.

RESULTS

Of the 104 carcinomas, negative E-cadherin immunoexpression was observed in seven (7%) cases, and positive immunoexpression in 97 (93%). E-cadherin categorised into negative versus positive expression did not associate with any of the established clinicopathological parameters. However, negative E-cadherin expression significantly predicted a poorer overall survival when compared with positive expression (P=0.006). In the multivariate analyses, negative E-cadherin and the presence of residual tumour after cytoreductive surgery were independent prognostic factors for survival (P=0.014 and P=0.034, respectively).

CONCLUSIONS

The presence of residual tumour after primary cytoreductive surgery and negative E-cadherin expression seem to be useful markers in patients with ovarian carcinomas likely to have an unfavourable clinical outcome. The assessment of E-cadherin immunoreactivity may be a useful prognostic indicator in ovarian cancer, complementary to established prognostic factors.