The study of elastic fibres in oral precancerous and cancerous lesions using Shikata's modified orcein stain: a retrospective study.

Abstract

Statement of the problem: Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer. During the invasion, tumour cells break through the basement membrane and penetrate the connective tissue to interact with the extracellular matrix. An attempt was made to evaluate the connective tissue changes in different grades of OSCCs, oral submucous fibrosis (OSMF) and Oral Epithelial Dysplasias. Literature related to the evaluation of malignant epithelial cells is vast but very sparse knowledge is available on the role of extracellular stromal fibres on tumour invasion in oral cancer and precancer especially on elastic fibres using Shikata's Modified Orcein Stain.

Purpose: To analyse the changes in elastic fibres in varying grades of OSCC, OSMF and Oral Epithelial Dysplasias using a special stain, Shikata's modified orcein stain.

Materials and method: A total of 100 cases were selected as the study group in this retrospective observational study. One section each was cut from 50 samples of varying grades of OSCC and 50 samples of varying grades of OSMF and oral leukoplakia. Ten samples of the control group were taken from the archives of the Department of Oral Pathology. Qualitative and quantitative analysis of elastic fibres was accomplished using set criteria. Spearman's test was done to evaluate the elastic fibres. Statistically insignificant results were obtained for quantitative and qualitative analysis of elastic fibres.

Results: A change in density in elastic fibres was observed in progression from early to advanced grades of OSCC, OSMF and oral epithelial dysplasia cases. A low expression of elastic fibres in tumour stoma indicates that the protective barrier against tumour progression is deficient, allowing the tumour to progress more easily and resulting in a poorer prognosis.

Conclusion: The elastic fibres undergo a change in density, orientation and packing in the stroma of varying grades of OSCC, OSMF and oral epithelial dysplasia cases. The unique feature of this study lies in the exploration of elastic fibres in OSCC which has not been done so far.