Bone decalcification to assess programmed cell death ligand 1 expression in bone metastases of non-small cell lung cancers

Publication date: Available online 8 January 2020Source: Journal of Bone OncologyAuthor(s): Guillaume Pontarollo, Cyrille B. Confavreux, Jean-Baptiste Pialat, Sylvie Isaac, Fabien Forest, Violaine Yvorel, Jean-Michel Maury, Nicolas Girard, Marie BrevetAbstractAs for molecular alterations of lung adenocarcinoma, it is critical that pathologists are able to give PD-L1 expression status before first-line of treatment. The present study compared PD-L1 expression (clone 22-C3) in decalcified using EDTA or formic acid and non-decalcified lung cancer metastases bone samples. Among the 84 bone samples analysed for PD-L1 expression, and independently of decalcification, TPS ≥ 1% was 25.0% and ≥ 50% was 11.4%. There was no significant difference between decalcified samples (n=45) and non-decalcified samples (n=39) for both TPS ≥ 1% (p=0.32) and TPS ≥ 50% (p=1). To conclude, we confirm decalcified bone metastasis specimens may be used for PD-L1 IHC in routine practice. These results also highlight potentially interesting specificities of the bone microenvironment that should be further studied
Source: Journal of Bone Oncology - Category: Cancer & Oncology Source Type: research