Objective: This study aimed to evaluate the immunohistochemical expression of PD-L1 or Ki-67 in oral squamous cell carcinoma (OSCC).

Methods: A hospital-based descriptive study has been carried out on 75 cases of OSCC received in the Department of Pathology at Muzaffarnagar Medical College. The expression of PD-L1 and Ki-67 has been evaluated utilizing immunohistochemistry and correlated with various clinicopathological parameters.

Results: Most cases of OSCC were observed in patients in the fifth and 6th decades of life, with the buccal mucosa being the most commonly affected site. Tobacco use was noted in 69.4% of patients. The majority of tumors were moderately differentiated. Increased expression of PD-L1 or Ki-67 was observed in poorly differentiated carcinomas. No significant correlation was found among PD-L1 and Ki-67 expression with age or gender. However, a strong correlation was identified among histological grade and the expression of these markers.

Conclusion: The findings emphasize the significance of evaluating patient habits and clinicopathological features to improve prognosis and guide treatment strategies in OSCC. PD-L1 and Ki-67 can serve as useful markers for assessing tumor aggressiveness and progression. However, further studies incorporating a wider range of markers are required to understand better their role in predicting treatment outcomes.

KEYWORDS: Immunoexpression, Oral Squamous Cell Carcinoma, PD-L1, Ki-67.