PD-L1 evaluation in head and neck squamous cell carcinoma: Insights regarding specimens, heterogeneity and therapy.
Pathol Res Pract
; 226: 153605, 2021 Oct.
Article
in En
| MEDLINE
| ID: mdl-34530257
ABSTRACT
Immunohistochemical assessment with combined positive score (CPS) of programmed death-ligand 1 (PD-L1) is the prerequisite for administration of checkpoint inhibitor therapy in head and neck squamous cell carcinoma (HNSCC). Practicing pathologists are required to assess PD-L1 in routinary work and can be faced up with practical issues not always addressed in clinical trials or guidelines, such as choice of specimen to test, the intrinsic heterogeneity in PD-L1 expression in tumors and the potential impact of already administered therapy, given that patients' material can be procured at several times of cancer natural history. In the present work, we review and discuss the recent literature regarding the assessment of PD-L1 in HNSCC from the perspective of the practicing pathologist, providing some evidence on the single issues. It emerges a general trend to an underestimation of PD-L1 expression in biopsies compared to resection specimens and to a higher degree of positivity in metastatic lymph nodes in respect to primary tumors. Moreover, therapy shows to have contrasting effect on PD-L1 expression. Although further studies are needed, taking into account the intrinsic heterogeneity in PD-L1 expression and the conflicting evidences, it may be speculated that the most recent material of patients in respect to the natural history of tumor can be the most reliable to evaluate PD-L1 expression.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Biomarkers, Tumor
/
B7-H1 Antigen
/
Squamous Cell Carcinoma of Head and Neck
/
Head and Neck Neoplasms
Type of study:
Diagnostic_studies
/
Guideline
Limits:
Humans
Language:
En
Journal:
Pathol Res Pract
Year:
2021
Document type:
Article
Affiliation country:
Italy