Programmed Death-ligand 1 Expression Analysis for Non-small Cell Lung Cancer in Tissues Sampled Using Different Methods

Abstract

This study aims at investigating the concordance of programmed death-ligand 1 (PD-L1) expression in non-small cell cancer tissues that have been sampled using different methods and its relationship with the pathologic parameters of tumors. Methods: PD-L1 expression assays were made on the cell blocks taken using fine needle aspiration, the small tissue samples representing endoscopic biopsy and the large tissue samples representing the resected tumor taken from the tumors of 100 subjects diagnosed with non-small cell lung cancer; their percentage values were evaluated and their groups were determined based on these values. Results: The average difference in expression rates found through different sampling methods was close to 0, and the values of such differences changed mostly in a narrow range. In paired comparisons, a good level of concordance was observed between all the sampling methods. The values were 0.8865 (SE: 0.0306, CI: 0.8264-0.9466) in the comparison of tumor tissue (TT) and small biopsy (SB): 0.8637, (SE: 0.033, CI: 0.7989-0.9285) TT to cell block (CB): 0.8916, (SE: 0.0272, CI: 0.8383-0.9449) SB tissue to the CB. Conclusion: Therefore, it can be concluded that the PD-L1 expression does not differ between the tissues sampled through various methods in non-small cell lung cancers.