Noura M. Kamal, Hend M. Salem And Heba M. Dahmoush,

ABSTRACT
Background: Salivary Gland Cancers Are A Group Of Neoplasms Having Biological, Histological And Clinical Diversity. This Diversity Represents A Challenge For Diagnosis, Classification And Management Of Salivary Gland Cancers. We Believe That The Present Study Is The First To Compare And Correlate The Immunohistochemical Expression Of EpCAM In Different Grades Of Mucoepidermoid Carcinoma (MEC) And Solid Variant Of Adenoid Cystic Carcinoma (solid AdCC) In Comparison With The Normal Salivary Glands, To Ascertain The Possible Diagnostic And Prognostic Significance As Well As, Propose EpCAM Targeted Therapy As A Possible Treatment Approach For Patients With Salivary Gland Tumors.

Materials and Methods: 60 Specimens (12 Normal Salivary Gland Tissue, 36 MEC And 12 Solid AdCC) Were Collected And EpCAM Membranous Expression Was Evaluated By Immunohistochemistry. The Total Immunoscore (TIS) Was Evaluated, Which Represented The Product Of The Proportion Score And The Intensity Score. 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, Different Grades Of MEC And Solid AdCC (p< 0.001). High Grade MEC (HG-MEC) And Solid AdCC Were Found To Be The Highest EpCAM Expressors. Although, Lack Of EpCAM Expression Was Detected In Two Cases Of HG-MEC And One Case Of Solid AdCC. Conclusion: EpCAM Was Frequently Detected In MEC And Solid AdCC Making These Tumours Potential Targets For Anti-EpCAM Therapies. 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.