Osteopontin expression in oral potentially malignant disorders and squamous cell carcinoma: association with early invasion but not with dysplastic grade

OBJECTIVE: To evaluate osteopontin (OPN) expression in oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) and explore its prognostic relevance. STUDY DESIGN: This cross-sectional study analyzed 120 cases from 2017 to 2022, including OPMD with varying degrees of epithelial dysplasia and OSCC. Immunohistochemical staining for OPN was performed, and clinicopathologic variables such as patient demographics, lesion site and size, clinical presentation, and histopathologic features were evaluated. Statistical analyses were conducted to assess associations between OPN expression and clinicopathologic parameters. RESULTS: Patients ranged from 22-92 years (mean: 59.3), with a slight female predominance (54.2%). The lateral tongue was the most affected site, and leukoplakia was the predominant clinical presentation. Mean lesion size was 15.8 mm, with mean duration of 23.2 months. OPN expression was detected in 68.2% of cases, with high intensity staining in 46.7%. While stronger OPN expression was noted at OSCC invasion fronts, no significant association was found between OPN levels and epithelial dysplasia grade. CONCLUSIONS: OPN does not appear to correlate with epithelial dysplasia or malignant transformation in OPMD. However, its overexpression at OSCC invasion fronts compared to adjacent areas suggests a role in early invasion, potentially helping identify initial lesions with more aggressive behavior.