Extracellular matrix in oral squamous cell carcinoma: Friend or foe?

Abstract

Background: Oral squamous cell carcinoma (OSCC) primarily spreads through direct invasion and/or lymphatic route. During the invasion, tumor cells break through the basement membrane, penetrate the connective tissue to interact with the extracellular matrix (ECM). An attempt was made to evaluate the connective tissue changes in different grades of OSCCs and their influence in predicting the biological behavior of these tumors. Materials and Methods: A total of 30 histologically proven cases comprising 5 normal mucosa, 10 well-differentiated OSCC's, 10 moderately differentiated OSCC's, and 5 poorly differentiated OSCC's were examined for the presence of any ECM changes by using special stains. Interpretation of staining intensity was carried out and statistically analyzed. Results: Van Gieson stain showed abundant thick collagen fibers, dispersed collagen fibers, thin few dispersed collagen fibers in well-, moderately- and poorly-differentiated OSCC's, respectively. Verhoeff's Van-Gieson showed negative staining for elastic fibers around tumor islands in different grades of OSCCs. PAS stain showed moderate staining for glycoprotein in well-differentiated OSCC and negative in moderately and poorly differentiated cases. Picrosirius red stain showed Type 1 collagen fibers in well and moderately differentiated OSCC cases and Type 3 collagen fibers in poorly differentiated cases. Conclusion: The observations of this study revealed altered staining reactions of the collagenous stroma and glycoproteins suggesting that tumor cells may release certain enzymes that play a role in the manipulation of ECM to enhance their own survival.

Keywords

• Extracellular matrix
• oral squamous cell carcinoma
• special stains