Prognostic Significance of P16 Expression Across Histopathological Grades of Oral Squamous Cell Carcinoma in a Tertiary Care Setting

Background: Oral squamous cell carcinoma (OSCC) is a common head and neck cancer, accounting for 90% of oral malignancies. Despite treatment advances, survival rates are still low. P16, a key regulator of the cell cycle, has emerged as a potential biomarker in various cancers, including OSCC. Objective: This study aimed to assess P16 expression across different OSCC grades and its value as a prognostic marker. Methods: This observational study was conducted at different centers including Department of Oral Medicine, Women Dental College Abattabad and Ayub Medical College Abbottabad, Pakistan in the duration from November, 2023 to April, 2024. Sixty OSCC patients were categorized into well-differentiated, moderately differentiated, and poorly differentiated groups, with 20 patients each. P16 expression was evaluated using immunohistochemistry on tissue samples. Data analysis included descriptive statistics, Chi-square tests, and multivariate logistic regression to determine associations between P16, tumor grade, and clinical outcomes like survival and recurrence. Results: P16 expression varied significantly with OSCC grade (p = 0.03). It was most prevalent in well-differentiated tumors (70%) and decreased in moderately (45%) and poorly differentiated tumors (20%). P16-positive patients showed longer survival (36.2 months) compared to P16-negative patients (28.9 months). Multivariate analysis confirmed P16 as a significant predictor of better survival (p = 0.01). Conclusion: P16 correlates with OSCC grade and may serve as a useful prognostic marker. Incorporating P16 evaluation in routine OSCC diagnostics could improve patient stratification and treatment outcomes.