Elsevier

Oral Oncology

Volume 39, Issue 3, April 2003, Pages 277-281
Oral Oncology

Mel-CAM (CD146) expression in parotid mucoepidermoid carcinoma

https://doi.org/10.1016/S1368-8375(02)00115-XGet rights and content

Abstract

Mel-CAM (CD146) is a cell–cell adhesion protein found in normal and tumoral tissues. The aim of this study was to analyse Mel-CAM expression in mucoepidermoid carcinoma (MEC), and assess its importance in prognosis and its utility in differentiating high-grade MEC from squamous cell carcinoma (SCC). Immunohistochemical expression of Mel-CAM in 41 parotid MEC was correlated with clinical parameters. Ten cases of oral cavity SCC were included for comparison. Mel-CAM expression was found in 92.7% of the MEC but was not expressed by the SCC. Mel-CAM expression was greater in intermediate/high grade tumors, was weaker in patients that presented local recurrence, regional and distant metastasis, but no correlation between Mel-CAM and clinical stage and survival of the patients was found. Decreased Mel-CAM expression can impair cellular contact properties, facilitating growth, cell spreading and metastasis in MEC. Mel-CAM can also be useful in differentiating high grade MEC from SCC.

Introduction

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor, affecting mainly parotid and palatal minor salivary glands [1]. Prognosis of MEC has been usually related to clinical stage of the patients and histological grading of the tumors [2]. Additionally, expression of some immunohistochemical markers, such as ki-67, has been associated with a worst prognosis [1], [3].

Mel-CAM (CD146 or MUC18) is a 113kD heterophilic cell–cell adhesion glycoprotein belonging to the immunoglobulin supergene family, whose gene is mapped to the short arm of the chromosome 11 [4]. This transmembrane molecule has been included in the group of the new endothelial antigens, and its expression is found in many normal tissues including endothelium, smooth muscle, Schwann cells and ductal and myoepithelial cells of salivary glands [5]. This protein is related to focal adhesion, cytoskeletal organization, intercellular interactions, maintenance of the cell shape, and cellular migration and proliferation control [4]. Mel-CAM is also expressed in tumor tissues, being related to tumor size and progression, metastatic potential and agressiveness [5].

Most available anti-Mel-CAM antibodies are only useful in frozen sections, limiting its use in paraffin specimens. Recently, a monoclonal antibody directed against Mel-CAM protein was developed and tested by Shih et al. [5] in paraffin-embedded specimens. The authors described Mel-CAM expression in several normal and tumoral tissues, including five cases of salivary gland tumors. To our knowledge, this is the only report of Mel-CAM expression in salivary gland tumors.

The aim of this paper is to assess the expression of Mel-CAM in parotid MEC, its correlation to clinical stage, histological grade and prognosis of these tumors, and its utility in differentiating high-grade MEC from squamous cell carcinoma (SCC).

Section snippets

Material and methods

Forty-one cases of parotid MEC were retrieved from the files of the Department of Head and Neck Surgery and Otorhinolaryngology, AC Camargo Cancer Hospital, São Paulo, Brazil. Clinical, treatment and follow-up data were obtained from the patients records. Histological slides were stained with haematoxilin & eosin, Schiff periodic acid and mucicarmine techniques, reviewed and graded according to Ellis and Auclair [1] in low, intermediate and high-grade tumors. Ten cases of oral cavity SCC were

Parotid MEC

The mean age of the 41 patients was 40 years (range 6–78 years), with 22 males (53.7%) and 19 females (46.3%), and 75.6% were Caucasians. The mean complaint time reported by the patients was 38.8 months (range 1–240 months) and the most common complaints were the presence of a tumor/nodule in the area (97.6% of the cases), pain (36.6%) and facial paralysis (12.2%). The mean size of the tumors was 4.6 cm (ranging from 2 to 10 cm), and 51.3% were fixed in the adjacent tissues. Invasion of the

Discussion

Immunohistochemical expression of several tumor and proliferation markers have been described in MEC but few have been associated to prognosis in these tumors [3]. Mel-CAM is a cell–cell adhesion molecule expressed in several normal tissues and also in certain tumoral tissues. It has been correlated to agressiveness, development of metastasis and a worst prognosis in some cancers [5]. Tumoral invasion and metastasis have been correlated to Mel-CAM expression in melanoma cells, however in other

Acknowledgements

This work was supported by FAPESP, Brazil

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