Association of Oral Biological and Immunohistochemical Expression of P53 and Ki-67 with Histopathological Grade and Clinical Outcomes in Oral Squamous Cell Carcinoma

Abstract

Background: Oral squamous cell carcinoma (OSCC) is a highly aggressive and poorly prognostic cancer. The present study assessed the immunohistochemical expression of p53 and Ki-67 in OSCC and their relationship with the histological grade and clinical outcome.

Methods: A cross-sectional observational study was made of 80 cases of histologically confirmed OSCC in the Department of Oral Biology, Khyber Medical University (KMU), Peshawar from September, 2025 to February, 2026. Formalin-fixed paraffin-embedded tissues were stained with p53 and Ki-67. The expression patterns were evaluated and correlated with the histological grades and available clinical parameters. A significance level of p < 0.05 was used.

Results: The majority of cases were moderately differentiated (45%), followed by well differentiated (35%) and poorly differentiated (20%) OSCC, with p53 overexpression increasing with increasing grade (36% in well differentiated, 67% in moderately differentiated, and 81% in poorly differentiated). Ki-67 labeling index also showed a progressive rise (18.4%, 32.7%, and 56.9% respectively; p < 0.05). There was a significant association between high expression of both markers and advanced clinical stage, lymph node metastasis, and increased recurrence.

Conclusion: The study shows that there is a strong positive correlation between increased expression of p53 and increased expression of Ki-67 and higher histological grades and aggressive clinical behavior in OSCC. These biomarkers could be useful as additional tools to traditional histopathology for better prognosis evaluation and risk stratification in oral cancer patients.