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Importance of choice of materials and methods in PD ‐L1 and TIL assessment in oropharyngeal squamous cell carcinoma
Author(s) -
De Meulenaere Astrid,
Vermassen Tijl,
Creytens David,
Aspeslagh Sandrine,
Deron Philippe,
Duprez Frederic,
Rottey Sylvie,
Van Dorpe Jo A,
Ferdinande Liesbeth
Publication year - 2018
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.13650
Subject(s) - subtyping , immunohistochemistry , biopsy , medicine , pd l1 , clone (java method) , basal cell , immunotherapy , oncology , carcinoma , pathology , cancer , biology , computer science , dna , genetics , programming language
Aims A great deal of research is being conducted into PD ‐L1 immunohistochemistry ( IHC ) and tumour‐infiltrating lymphocytes ( TIL s) as predictive or prognostic biomarkers for immunotherapy, although several practical issues exist concerning their assessment. The aim of this research was therefore to assess the importance of choice of materials and methods in PD ‐L1 and TIL s scoring in oropharyngeal squamous cell carcinoma ( OSCC ). Methods and results IHC for PD ‐L1 ( SP 142 and 22C3 clone) and TIL s subtyping was performed on formalin‐fixed paraffin‐embedded tissue slides (biopsy, resection and/or lymph nodes specimens) of 99 patients with OSCC . A comparative analysis of PD ‐L1 and TIL s scoring was made between different types of tissue specimens, between different PD ‐L1 clones, between TIL s and different subsets of TIL s and between the quantitative and semiquantitative assessments. PD ‐L1 scoring resulted in fair to moderate agreement for 22C3 and SP 142 between various tissue specimens, with higher agreement at higher cut‐off values, and in moderate agreement for 22C3 versus SP 142. Evaluation by four independent observers proved substantial inter‐rater agreement for both clones with high consistency in their ratings. Moderate agreement was observed for TIL s and TIL s subsets for the comparison between biopsy and resection. Lastly, strong correlations were found between quantitative and semiquantitative assessment for all PD ‐L1 and TIL s scores. Conclusions Our results highlight the challenges associated with the evaluation of PD ‐L1 and TIL s in OSCC . Further research is warranted to evaluate the use of these biomarkers in order to allow implementation of PD ‐L1 and TIL s infiltrate as biomarkers in daily clinical practice.