Clinical significance of aberrant vimentin expression in oral premalignant lesions and carcinomas.

OBJECTIVE: To investigate the clinical significance of vimentin expression at early and late events of tobacco/areca nut-associated oral tumorigenesis. MATERIALS AND METHODS: Immunohistochemistry (IHC) was carried out on paraffin-embedded tissues of oral mucosa normal (n = 10), inflammatory lesions (n = 19), leukoplakia (n = 52), submucous fibrosis (n = 71) and tumours/cut margins (n = 227 each), using anti-vimentin antibody, and the expression profile was correlated with patients' clinical parameters. Immunofluorescence, Western blot and RT-PCR analysis were also carried out wherever adequate and fresh tissues were available. RESULTS: Aberrant vimentin expression was seen in hyperplastic, dysplastic and fibrotic tissues, which showed statistically significant correlation with the histopathological grade of dysplasia (P = 0.001) and fibrosis (P = 0.009). Vimentin expression also showed statistically significant correlation with tumour size (P = 0.048), clinical stage (P = 0.013), regional lymph node metastases (P = 0.001), local recurrence (P = 0.001) and survival (P = 0.021) of patients with oral squamous cell carcinoma (OSCC). Its expression in invasive fronts statistically correlated with development of nodal metastasis and local recurrence. CONCLUSIONS: Our results suggest possible role of vimentin in early events of tobacco/areca nut-associated oral tumorigenesis, which may prove useful to predict the malignant potential of high-risk oral lesions. Further, association between vimentin expression in invasive fronts and aggressive phenotype of tumours may help clinicians to choose the appropriate treatment modality for OSCC management.