Immunohistochemical expression of epithelial cell adhesion molecule (EpCAM) in mucoepidermoid carcinoma compared to normal salivary gland tissues

OBJECTIVES

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor which displays biological, histological and clinical diversity thus representing a challenge for its diagnosis and management. Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein identified as a tumor specific antigen due to its frequent overexpression in the majority of epithelial carcinomas and its correlation with prognosis. It is considered to be a promising biomarker used as a therapeutic target already in ongoing clinical trials. The purpose of this study was to investigate the pattern, cellular characterization and level of EpCAM expression in MEC and demonstrate its correlation with histologic grading which may benefit future clinical trials using EpCAM targeted therapy.

MATERIALS AND METHODS

48 specimens (12 normal salivary gland tissue and 36 MEC) were collected and EpCAM membranous expression was evaluated by immunohistochemistry. Total immunoscore (TIS) was evaluated, the term 'EpCAM overexpression' was given for tissues showing a total immunoscore >4.

RESULTS

A highly significant difference was observed between TIS percent values in control and different grades of MEC (p<0.001). High grade MEC (HG-MEC) was the highest EpCAM expressor. In addition, EpCAM expression pattern differed among the different grades.

CONCLUSION

EpCAM expression was detected in MEC, and its overexpression correlated with increasing the histological grade. The diffuse membranous expression in HG-MEC could be of diagnostic value in relation to the patchy expression observed in both low grade and intermediate grade MEC.

Increased expression of MUC-1 has close relation with patient survivor in high-grade salivary gland mucoepidermoid carcinoma

PURPOSE

High-grade mucoepidermoid carcinoma (MEC) is an infrequent malignant neoplasm originates most commonly in the salivary glands with poor prognosis. Thus far, there is little knowledge on MUC-1 expression in high-grade MEC or how it may relate to patient survival. The aim of this study was to determine the extent of MUC-1 expression in high-grade MEC and correlate expression with clinic outcome.

METHODS

Surgical specimens from 62 cases of primary high-grade MEC and 10 cases of normal salivary gland tissue were examined by immunohistochemistry. The relationship between MUC-1 expression and the clinicopathological data and patient survival was analyzed.

RESULTS

The disease-free survival rates were 54.6% (3 years) and 37.7% (5 years) for high-grade MEC patients. Patient who with primary location at submandibular gland have the worst prognosis (P = 0.042) in comparing with other sites. High expression of MUC-1 in high-grade MEC was significantly correlated with lymphatic/regional metastasis (P = 0.003) and clinic stage (P = 0.02), and high expression of MUC-1 (>75%) was confirmed to be significant independent prognostic factors in high-grade MEC patients [HR 2.929 (95% CI 1.246-6.881); P < 0.0137].

CONCLUSIONS

The findings suggest that high levels of MUC-1 expression may be a potential marker for worse outcome in high-grade MEC and could be used as a new molecule target to improve outcomes for these patients in the future.