Recommended Citation
Arora K, Mehrotra H, Saikia K, Abou Shaar R, Alhamar M, Chitale DA. Correlation of PD-L1 expression, clinicopathologic and molecular characteristics in an array of solid tumors: A large-scale real world study. Laboratory Investigation 2021; 101(Suppl 1):499-501.
Document Type
Conference Proceeding
Publication Date
3-1-2021
Publication Title
Laboratory Investigation
Keywords
endogenous compound, programmed death 1 ligand 1, aged, cancer staging, cancer survival, clinical assessment, clinical outcome, cohort analysis, conference abstract, controlled study, disease free survival, female, gene expression, head and neck carcinoma, histopathology, human, human tissue, immunohistochemistry, immunotherapy, Kaplan Meier method, kidney carcinoma, log rank test, major clinical study, median survival time, microsatellite instability, non small cell lung cancer, overall survival, prospective study, protein expression, race, transitional cell carcinoma, univariate analysis, uterine cervix carcinoma
Abstract
Background: Programmed death ligand-1 (PD-L1) is a predictive marker of anti-programmed death protein 1 (PD- 1)/PD-L1 therapies for solid tumors. Limited literature exists correlating PD-L1 expression, clinicopathological & molecular profiles. We aimed to 1) correlate PD-L1 immunohistochemistry (IHC) results with these profile across multiple solid tumors & 2) assess clinical outcomes (overall survival (OS) & disease-free survival (DFS)) of PD-L1 status with / without anti-PD-L1 immunotherapy (IT).
Design: All cases tested for PD-L1 IHC over 2 years (Aug 2019-Sep 2020) were retrieved for this study. Clinicopathological variables recorded included age, race, tumor type, type of PD-L1 clone, PD-L1 status (Tumor Proportion Score (TPS): negative:50%), Combined Positive Score (CPS): negative10), clinical stage, anti-PD-L1 IT. Microsatellite instability (MSI) status using IHC & Ploymerase chain reaction (PCR) assays was recorded. High PD-L1 was defined as PD-L1 expression of TPS >50%/CPS>10. Outcome studies included OS and DFS after generating Kaplan-Meier curves & compared using log rank test. Univariate analysis using Cox regression models were also used.
Results: There were 205 cases tested for PD-L1 by IHC. Cohort included non-small cell lung cancers (127), head & neck carcinomas (37), gastric or gastroesophageal carcinoma (20), kidney or urothelial carcinoma (16), cervical carcinomas (5). Median age was 70 years (range 28-90). Most were high stage cancers [stage 1: 5/205, stage 2: 5/205, stage 3: 30/205, stage 4 165/205]. PD-L1 IHC clones included: 22C3 (152/205), 28-8 (21/205) & both (32/205). High PD-L1 expression was observed in 52/205 (25.3%), out of which [37/127 (29.1%) were adenocarcinoma, 13/54 (24%) were squamous cell carcinoma, 2/24 (4.1%) others]. Anti PD-L1 IT was given in 65/205 (31.7%) patients. Anti PD-L1 IT was significantly associated with longer median survival OS (p=0.015) & DFS (p=0.004) (Figure 1). PD-L1 status was significantly associated with OS (p=0. 034) but not DFS (p=0. 076) (Figure 1). High PD-L1 had shorter median survival and higher hazards of death in OS (HR=5.4, CI-1.3-23.1) irrespective of IT. Association between three groups of PD-L1 status when compared with IT was statistically significant (p=0.048, Figure 2). PD-L1 & MSI testing was available in 29 patients & did not show any statistical correlation in this small cohort. No significant difference in survival for those received IT (4/29) vs no IT (25/29) & tested for both PD-L1 & MSI (OS: p= 0.277, DFS: p= 0.107).
Conclusions: This study supports the rational approach for PD-L1 therapy. High PD-L1 expression is more commonly seen in adenocarcinoma. Expression of high PD-L1 is associated with worse OS but not DFS. PD-L1 IT is significantly associated with longer median survival, OS & DFS. Larger, prospective studies are needed to support our findings.
Volume
101
Issue
Suppl 1
First Page
499
Last Page
501
Comments
doi:10.1038/s41374-021-00557-x