METHODOLOGY: Immunohistochemistry (IHC) was performed on 56 OL tissue samples, categorized equally into progressive (transformed to higher-grade dysplasia or OSCC within 3 years) and non-progressive groups. Expression levels of E-cadherin, N-cadherin, Twist, PD-1, and PD-L1 were systematically assessed.
RESULTS: Progressive OL cases showed descriptive trends of lower E-cadherin expression, higher N-cadherin and Twist expression compared with non-progressive cases; however, these EMT-marker differences were not statistically significant. PD-1 expression was significantly higher in progressive OL (p = 0.038) compared with non-progressive OL. When stratified into non-progressive, dysplasia-progressive, and OSCC-progressive subsets, PD-L1 expression demonstrated significant variation (p = 0.018). Higher PD-1 expression was significantly associated with progressive OL in males (p = 0.02) and correlated with a shorter time to progression (τb = 0.456, p = 0.004).
CONCLUSION: The findings suggest that immune checkpoint markers, particularly PD-1 and PD-L1, may be associated with progression in OL and may warrant further validation as adjunctive prognostic markers.