TY - JOUR
T1 - PD-L1 testing and squamous cell carcinoma of the head and neck
T2 - A multicenter study on the diagnostic reproducibility of different protocols
AU - Crosta, Simona
AU - Boldorini, Renzo
AU - Bono, Francesca
AU - Brambilla, Virginia
AU - Dainese, Emanuele
AU - Fusco, Nicola
AU - Gianatti, Andrea
AU - L’Imperio, Vincenzo
AU - Morbini, Patrizia
AU - Pagni, Fabio
N1 - Publisher Copyright:
© 2021 by the authors.
PY - 2021/1/2
Y1 - 2021/1/2
N2 - Immune checkpoint inhibitors for blocking the programmed cell death protein 1 (PD- 1)/programmed death-ligand 1 (PD-L1) axis are now available for squamous cell carcinoma of the head and neck (HNSCC) in relapsing and/or metastatic settings. In this work, we compared the resulting combined positive score (CPS) of PD-L1 using alternative methods adopted in routine clinical practice and determined the level of diagnostic agreement and inter-observer reliability in this setting. The study applied 5 different protocols on 40 tissue microarrays from HNSCC. The error rate of the individual protocols ranged from a minimum of 7% to a maximum of 21%, the sensitivity from 79% to 96%, and the specificity from 50% to 100%. In the intermediate group (1 ≤ CPS < 20), the majority of errors consisted of an underestimation of PD-L1 expression. In strong expressors, 5 out of 14 samples (36%) were correctly evaluated by all the protocols, but no protocol was able to correctly identify all the “strong expressors”. The overall inter-observer agreement in PD-L1 CPS reached 87%. The inter-observer reliability was moderate, with an ICC of 0.774 (95% CI (0.651; 0.871)). In conclusion, our study showed moderate interobserver reliability among different protocols. In order to improve the performances, adequate specific training to evaluate PD-L1 by CPS in the HNSCC setting should be coordinated.
AB - Immune checkpoint inhibitors for blocking the programmed cell death protein 1 (PD- 1)/programmed death-ligand 1 (PD-L1) axis are now available for squamous cell carcinoma of the head and neck (HNSCC) in relapsing and/or metastatic settings. In this work, we compared the resulting combined positive score (CPS) of PD-L1 using alternative methods adopted in routine clinical practice and determined the level of diagnostic agreement and inter-observer reliability in this setting. The study applied 5 different protocols on 40 tissue microarrays from HNSCC. The error rate of the individual protocols ranged from a minimum of 7% to a maximum of 21%, the sensitivity from 79% to 96%, and the specificity from 50% to 100%. In the intermediate group (1 ≤ CPS < 20), the majority of errors consisted of an underestimation of PD-L1 expression. In strong expressors, 5 out of 14 samples (36%) were correctly evaluated by all the protocols, but no protocol was able to correctly identify all the “strong expressors”. The overall inter-observer agreement in PD-L1 CPS reached 87%. The inter-observer reliability was moderate, with an ICC of 0.774 (95% CI (0.651; 0.871)). In conclusion, our study showed moderate interobserver reliability among different protocols. In order to improve the performances, adequate specific training to evaluate PD-L1 by CPS in the HNSCC setting should be coordinated.
KW - HNSCC
KW - Head and neck carcinoma
KW - PD-L1
KW - Pembrolizumab
UR - http://www.scopus.com/inward/record.url?scp=85099584178&partnerID=8YFLogxK
U2 - 10.3390/cancers13020292
DO - 10.3390/cancers13020292
M3 - Article
SN - 2072-6694
VL - 13
SP - 1
EP - 10
JO - Cancers
JF - Cancers
IS - 2
M1 - 292
ER -