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

摘要

As 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. Amongst 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.