PD-L1 expression in squamous-cell carcinoma and adenocarcinoma of the lungJanžič, Urška (Avtor) Kern, Izidor (Avtor) Janžič, Andrej (Avtor) Čavka, Luka (Avtor) Čufer, Tanja (Avtor) lung cancersquamous-cell lung canceradenocarcinomatumor cellsimmune cellsPD-L1 expressionWith introduction of immunotherapy (IT) into the treatment of advanced non-small-cell lung cancer (NSCLC), a need for predictive biomarker became apparent. Programmed death ligand 1 (PD-L1) protein expression is most widely explored predictive marker for response to IT. We assessed PD-L1 expression in tumor cells (TC) and immune cells (IC) of squamous-cell carcinoma (SCC) and adenocarcinoma (AC) patients. We obtained 54 surgically resected tumor specimens and assessed PD-L1 expression by immunohistochemistry after staining them with antibody SP142 (Ventana, USA). Clinicopathological characteristics were acquired from the hospital registry database. Results were analyzed according to cut-off values of % 5% and % 10% of PD-L1 expression on either TC or IC. 29 (54%) samples were AC and 25 (46%) were SCC. PD-L1 expression was significantly higher in TC of SCC compared to AC at both cut-off values (52% vs. 17%, p = 0.016 and 52% vs. 14%, p = 0.007, respectively) no difference in PD-L1 expression in IC of SCC and AC was found. In AC alone, PD-L1 expression was significantly higher in IC compared to TC at both cut-off values (72% vs. 17%, p < 0.001 and 41% vs. 14%, p = 0.008, respectively), while no significant difference between IC and TC PD-L1 expression was revealed in SCC. Our results suggest a significantly higher PD-L1 expression in TC of SCC compared to AC, regardless of the cut-off value. PD-L1 expression in IC is high in both histological subtypes of NSCLC, and adds significantly to the overall positivity of AC but not SCC.Association of Radiology and Oncology20172024-05-31 14:52:23Neznano19022UDK: 616-006.6:615.37ISSN pri članku: 1318-2099DOI: 10.1515/raon-2017-0037COBISS_ID: 4381553Ljubljanaslby Authors