The Expression of Programmed Death Ligand-1 within Stages of Oral Squamous Cell Carcinoma: Immunohistochemical Analysis

ABSTRACT

Background: Oral squamous cell carcinoma is prevalent in South Asian countries with rising cases of its incidence and mortality. Despite advancements in treatment, survival and recurrence rates are poor. Immunotherapy is a novel therapeutic modality in immunooncology. Immune checkpoint proteins are under investigation for clinical implications amongst which Programmed Death Ligand-1 has shown valuable results in certain malignancies. Aims: To determine the immunohistochemical expression of Programmed Death Ligand-1(PD-L1) in oral squamous cell carcinoma and to find an association of Programmed Death Ligand-1 with stage and clinicopathological parameters of oral squamous cell carcinoma.Study Design:Cross-sectional study.Place and Duration of StudyZiauddin Medical University, Karachi, 1 Year duration during 2018-2019.Methods: A total number of140 biopsy confirmed cases of oral squamous cell carcinoma were recruited in the study. Immunohistochemical expression of Programmed Death Ligand-1 was evaluated and associated with the clinicopathological parameters of oral squamous cell carcinoma (OSCC). The data was statistically analyzed through Descriptive statistics and Chi square test by using SPSS v.20.Results: Out of 140 participants, 74% were males (n=103) and 26% were females (n=37). Programmed Death Ligand-1 positivity was observed in 62.1% of cases (n=87). The Mean age of the participants was 48.91 ± 11.7 years. The most common site of cancer involvement was buccal mucosa and majority of participants were habitual of consuming chewable products i.e. Pan, Gutka and betel nut (89; 64%). Stage III and IV tumours comprised a major portion of cases in our study.(52; 37%), (56; 40%).A statistically significant p-value was noted for the association of Programmed Death Ligand-1 with stage II and IV tumours. (P-values 0.029, 0.001)The association of Programmed Death Ligand-1 with other variables such as age, gender, ethnicity, sites or habits was not statistically significant.Conclusion:This study concludes that the statistical significance of Programmed Death Ligand-1 expression with tumour stage is suggestive of worsening prognosis and might have detrimental effects as tumour progresses in advanced stage. Programmed Death Ligand-1 positivity in patients having oral squamous cell carcinoma could be useful in future research in the light of cancer immunotherapy which has shown success in oncology.