Immunoexpression of Programmed Death-1 Receptor (PD-1) and Programmed Death-Ligand 1 (PD-L1) in Non-Small-Cell Lung Carcinoma and Its Correlation With Other Clinicopathological Parameters: A Cross-Sectional Study From North India.

Aim To study the prevalence of programmed death-1 receptor (PD-1) and programmed death-ligand 1 (PD-L1) positive cases in non-small-cell lung carcinoma (NSCLC) and their association with other clinicopathological parameters in a tertiary care setting in North India. Material and methods One hundred histologically proven NSCLC cases having sufficient tumor material from July 2016 to July 2018 were examined, and the prevalence of PD-1 and PD-L1 positivity in NSCLC was studied. In addition, H&E-stained sections were reviewed, and 100 consecutive cases meeting study criteria were identified as study cases. Histopathological categorization was done using a panel of immunohistochemical markers. Statistical analysis and results The PD-1 positivity in lymphocytes was 29% (95% CI: 20.4%-38.9%). Membranous positivity for PD-L1 in tumor cells was 27% (95% CI: 18.6%-36.8%) and in tumor-infiltrating lymphocytes was 22% (95% CI: 14.3%-31.4%). There was no statistically significant association between PD-1 or PD-L1 status with age, gender, smoking, pleural effusion, clinical stage, histological type, or lymphocyte infiltration. Conclusion The moderately high prevalence may justify routine testing for PD-1 or PD-L1 in NSCLC, which should preferably be carried out in all cases rather than any selected subsets. However, there was no significant correlation between PD-1 and PD-L1 with the clinical parameters studied.