TY  - EJOU
AU  - Campedel, Luca 
AU  - Seisen, Thomas 
AU  - Varinot, Justine 
AU  - Cancel-Tassin, Géraldine 
AU  - Ruffion, Alain 
AU  - Mazancourt, Emilien Seizilles De 
AU  - Decaussin-Petrucci, Myriam 
AU  - Robert, Grégoire 
AU  - Vuong, Nam-Son 
AU  - Philipp, Magali 
AU  - Compérat, Eva 
AU  - Rouprêt, Morgan 
AU  - Cussenot, Olivier 

TI  - Standardizing immunohistochemistry methodology for evaluation of PD-1 and PDL-1 expression in upper tract urothelial  carcinoma
T2  - Canadian Journal of Urology

PY  - 2021
VL  - 28
IS  - 3
SN  - 1488-5581

AB  - <b>Introduction:</b> Controversy regarding the prognostic and/or predictive role of PD-1 and PD-L1 expression for upper tract urothelial carcinoma (UTUC) could partly be explained by inconsistencies in the immunohistochemistry (IHC) methodology. The objective is to standardize the methodology for routine evaluation of PD-1 and PD-L1 expression in UTUC patients.<br/>
<b>Materials and methods:</b> Twenty-two cases treated with radical nephroureterectomy between 1996 and 2015 at 11 French hospitals were randomly selected to compare different methodologies for evaluation of PD-1 and PD-L1 expression. IHC was carried out on whole tissue sections and 0.6 mm- or 2 mm-core tissue micro-arrays (TMAs) using PD-1 NAT105 and PD-L1 28.8 or E1L3N on both tumor cells and tumor-infiltrating immune cells (TILs). Results obtained with whole tissue sections (WTS) were compared to those obtained with 0.6 mm- and 2 mm-core TMAs. Concordance was evaluated using Kappa coefficient.<br/>
<b>Results:</b> For evaluation of PD-1 and PD-L1 expression, the best concordance with WTS was observed using the PD-1 NAT105 and PD-L1 28.8 antibody on 2 mm-core TMAs, with a 5% cut-off for positivity on TILs and tumor cells, respectively (Kappa = 0.8).<br/>
<b>Conclusions:</b> The most accurate methodology for routine evaluation of PD-1 and PD-L1 expression in UTUC may be based on 2 mm-core TMAs using NAT105 and 28.8 antibodies with a 5% cut-off for positivity on TILs and tumor cells, respectively.
KW  - tissue microarray
KW  -  upper tract urothelial  carcinoma
KW  -  immune checkpoint inhibitors
KW  -  PD-1
KW  -  PD-L1 quantification
KW  -  whole tissue sections

DO  -