Consistency Analysis of Programmed Death-Ligand 1 Expression between Primary and Metastatic Non-Small Cell Lung Cancer: A Retrospective Study

Abstract

Background: Programmed death-ligand 1 (PD-L1) expression in non-small cell lung cancer (NSCLC) is considered as a predictive biomarker of anti-PD-1/PD-L1 cancer therapies. However, the correlation of PD-L1 expression status between the primary and paired metastatic NSCLC is still not clear. The current study aims to address this specific issue. Materials and Methods: The PD-L1 expression of the primary and paired metastatic lesions from 110 patients with NSCLC was retrospectively evaluated by immunohistochemical assay using Anti-PD-L1 antibody, Clone 22C3. The results were assessed by the Tumor Proportion Score (TPS) using cutoff values of <1%, 1%-49% and ≥50%. Meanwhile, the Cohen's kappa coefficient (k) of agreement was calculated. Results: An overall concordance rate of the PD-L1 expression between the primary and metastatic lesions was 61% (63/103) (k = 0.39, and P < 0.001). If using TPS considering 1% and 50% as a threshold, the inconsistent rate was 28/103 (27.2%) paired specimens (k = 0.46, and P < 0.001) and 14/103 (13.6%) paired specimens (k = 0.53, and P < 0.001), respectively. Moreover, the concordance of the PD-L1 expression between primary and metastatic tumor was also analyzed according to the clinical stages within the untreated group of patients. We observed that for patients with stage I-III NSCLC, the concordance rate of the PD-L1 expression between primary and metastatic lesions was 81.3% and 100% when using 1% and 50% as threshold, respectively. While in stage IV patients, the concordance rate of the PD-L1 expression between the primary and metastatic lesions drops to 71.4% and 85.7%, respectively. Conclusion: The PD-L1 expression was dynamic as tumor developed, which was valuable in selecting the proper type of sample for accurately evaluating the prognosis of using pembrolizumab as first or second line treatment.

PD‐L1 expression in NSCLC: Role of cell blocks and concordance between samples

“…Kim instead observed higher concordance between the primary and metastatic NCSLC (concordance rate: 75.2%). Intermediate results were found by Xu 24 (concordance rate: 62.5%; k = 0.497) and Luo 25 (concordance rate: 61%; k = 0.39). These intermediate values were similar to those calculated in our series, although we considered only a limited number of cases (50 cases form 25 patients), independently from type, site, and time.…”

How can artificial intelligence models assist PD-L1 expression scoring in breast cancer: results of multi-institutional ring studies

“…The Fleiss’ kappa statistic (FKS) was applied for the concordance analysis on the 2- and 4-category PD-L1 (SP142) IC scores 28 , 29 . FKS is an extension of Cohen’s kappa for three raters or more 30 . The FKS can be interpreted as “weak,” “moderate,” “strong,” and “near perfect” for its value in (0.4, 0.6), (0.6, 0.8), (0.8, 0.9), and (0.9, 1), respectively 11 , 31 .…”

Integrating endobronchial ultrasound bronchoscopy with molecular testing of immunotherapy biomarkers in non-small cell lung cancer

“…In addition, the process of collecting, processing and staining tissue blocks is not necessarily standardised across different sites and this can collectively influence test performance and accuracy. Direct comparison between different PD-L1 IHC assays suggests that individual tests cannot be interchangeably used in clinical practice (7), however other groups have shown that 22C3, 28-8, SP263 but not SP142 can be used interchangeably (8).…”