PT  - JOURNAL ARTICLE
AU  - Tancoš, Vladimír
AU  - Farkašová, Anna
AU  - Kviatkovská, Zuzana
AU  - Grendár, Marián
AU  - Líšková, Alena
AU  - Huťka, Zdenko
AU  - Plank, Lukáš
TI  - Expression of programmed death-ligand 1 protein in pulmonary squamous cell carcinoma correlates with tumour necrosis but not with tumour differentiation
AID  - 10.1136/jclinpath-2020-207171
DP  - 2022 Jun 01
TA  - Journal of Clinical Pathology
PG  - 373--378
VI  - 75
IP  - 6
4099  - http://jcp.bmj.com/content/75/6/373.short
4100  - http://jcp.bmj.com/content/75/6/373.full
SO  - J Clin Pathol2022 Jun 01; 75
AB  - Aims Pulmonary squamous cell carcinoma (SqCC) represents the second most common non-small cell lung carcinoma type. The mechanisms which regulate programmed death ligand 1 (PD-L1) expression in this form of lung cancer are not fully elucidated yet.Methods We immunohistochemically determined the level of PD-L1 expression using the Tumour Proportion Score system in surgical resections of 133 patients with pulmonary SqCC. The results from PD-L1 immunohistochemistry were analysed in relation to tumour differentiation and the presence of necrotic areas comprising at least 20% of the tumour mass.Results No significant differences in terms of PD-L1 expression were found between SqCC subtypes as defined by the current WHO classification: better differentiated, keratinising tumours (12/24, 50.0 %) compared with less differentiated, non-keratinising and basaloid forms (62/109, 56.9 %) were PD-L1 positive in a comparable proportion of cases (p=0.1903). Contrary to that, SqCCs with the presence of necrosis (51/61, 83.6 %) had significantly more PD-L1-positive cases (p<0.001) compared with SqCCs without necrotic areas (23/72, 32.0 %)Conclusions We demonstrated that PD-L1 expression in pulmonary SqCCs does not correlate with the traditionally defined degree of differentiation of these tumours. On the other hand, we found a significant association between the positive result of PD-L1 immunohistochemistry and tumour necrosis. Further investigation regarding the role of hypoxic pathways as presumable inducers of PD-L1 expression in pulmonary SqCCs might contribute to the understanding of this phenomenon.Data are available upon reasonable request. Deidentified patient data.