Background: The extracellular matrix (ECM) is a dynamic tissue that provides nutrition and support to overlying epithelium. During tumorigenesis, the tumor microenvironment (TME) dysregulates the ECM. This is reflected by morphological changes seen in collagen and elastic fibers and is thought to facilitate metastasis.
Aim: To study the degradation of elastic fibers in different grades of oral squamous cell carcinoma (OSCC) and in oral epithelial dysplasia (OED) using histochemistry and to correlate it to the TNM stage of OSCC.
Materials and methods: Tumor cores from 38 cases of OSCC (well-differentiated[15], moderately differentiated[14], and poorly differentiated[9]) and 15 incisional biopsies of OED were analyzed. Hematoxylin-eosin and Verhoeff's-Van Gieson (VVG) stains were used. The stained sections were assessed for morphological changes in elastic fibers.
Statistical analysis: Data were analyzed using Statistical Package for Social Sciences (SPSS) version 22 software. Fisher's exact, Kruskal-Wallis, one-way ANOVA, and Turkey post hoc tests were used to establish significance (P ≤ 0.05). Spearman's correlation test was used to correlate elastin fiber degradation with TNM stage of OSCC.
Results: All grades of OSCC showed absence of elastic fibers around the tumor islands. Elastic fiber degradation (fragmented and clumped type fibers) increased proportionately with the grade and TNM stage of OSCC. In OED, A significant reduction in the amount of elastic fibers with increasing grade was noted.
Conclusion: A positive correlation was noted between elastin degradation and grade and stage of OSCC. Therefore, it may be implicated in tumor progression of OSCC.
Keywords: Elastic fibers; oral epithelial dysplasia; oral squamous cell carcinoma; tumor microenvironment.