PD-L1 in Oral Cavity Cancers-Audit for Tertiary Care Center in India

There is no data on the expression of PD-L1 in oral cavity cancers from the Indian population. Hence, this audit was done to estimate the incidence of PD-L1 expression in oral cavity cancers and detect factors affecting the same. Data of 340 cases of oral cavity cancer who were advised for PD-L1 gene expression testing were collected from the head and neck OPD of Tata Memorial Hospital from the year 2018 to 2023. These cases were evaluated for demographic details, i.e., age and gender, and also for factors such as performance status (PS) as per the Eastern Cooperative Oncology Group (ECOG) scale, subsite of oral tumor, histopathology, and grade. Descriptive statistics were used for analysis. Factors affecting PD-L1 gene expression were sorted using ordinal logistic regression analysis. In total, 340 patients were evaluated with a median age of 48 years (range, 17-79; interquartile range, 40-55), and PD-L1 expression was divided as scores and was observed that Tumor Proportion Score (TPS) 0% was seen in 34 patients (10.0%), TPS 1-5% was seen in 70 patients (20.6%), TPS 6-10% was seen in 29 patients (8.5%), TPS 11-20% was seen in 29 patients (8.5%), TPS 21-30% was seen in 33 patients (9.7%), TPS 31-50% was seen in 44 patients (12.9%), TPS 51-75% was seen in 47 patients (13.8%), and TPS > 75% was seen in 54 patients (15.9%). Univariate analysis was run to determine the distribution of TPS scores within each variable under age, gender, sample collection site, differentiation of tumor, and subsite of tumor. This is one of the first studies evaluating data on the expression of PDL-1 in oral cavity cancers in the Indian population and the factors affecting it. The data provides novel insights into many factors potentially affecting the expression of PDL-1 in oral cavity cancers and in the future, can be of help in developing treatment plans with various immunotherapies.