Association of Stathmin (Op18) with TNM Staging and Grading of Oral Squamous Cell Carcinoma and Its Role in Tumor Progression.

AIM: The purpose of the study was to evaluate the expression of stathmin in different histological grades and tumor, node, metastasis (TNM) staging of Oral carcinoma and various grades of oral dysplasia. The study also aims at observing the stathmin expression with respect to lymph node metastasis. MATERIALS AND METHODS: A total of 90 histopathologically confirmed tissue sections were acquired, of which 30 sections of oral dysplasia, 30 oral squamous cell carcinoma (OSCC) and 30 normal tissue sections were stained immunohistochemically with stathmin. The tissue sections, were categorized into different grades of oral dysplasia and OSCC based on histopathological examination. For estimation of stathmin expression, manual examination of 300 cells was done in a minimum of five different areas of tissue section and a mean proportion of positive-stained cells were determined. The statistical analysis of the results was done using ANOVA test. RESULTS: A statistically significant increase in mean staining scores of stathmin in OSCC group compared to dysplasia and control groups. A statistically significant difference was observed in different grades of dysplasia and OSCC groups. Stage III and stage IV OSCC tissue sections showed high intensity staining scores of stathmin expression. CONCLUSION: An increased expression of stathmin was detected in various grades of OSCC and also with respect to staging of oral cancer. Half the cases of OSCC with lymph node metastasis showed high intensity scores of stathmin. Based on the above facts, stathmin expression was indicated as a potential tool for predicting the outcome of oral cancer patients with lymph node metastasis and its expression was increased in the group with poor prognosis. CLINICAL SIGNIFICANCE: Any damage/mutation to stathmin can result in defects in cell division resulting in aneuploidy and in turn cancers. In this study, the results showed that there is a differential expression of stathmin in the early and the advanced grades and different TNM stages of OSCC. A high expression of stathmin was observed in all the cases with lymph node metastasis. These observations prove that stathmin has an important role in the progression, tumorigenicity, and prognosis of the oral cancer.