Programmed Death Ligand-1 (PD-L1) Expression in Either Tumor Cells or Tumor-Infiltrating Immune Cells Correlates With
Brandon R Driver1, Ross A Miller1, Tara Miller1
1From the Departments of Pathology and Genomic Medicine (Drs Driver, R.A. Miller, T. Miller, Deavers, Gorman, Mody, Ge, Barrios, and Cagle), Medicine (Dr Bernicker), and Surgery (Dr Kim), Houston Methodist Hospital, Houston, Texas.
Context:
- Programmed death ligand-1 (PD-L1) expression in non-small cell lung carcinoma (NSCLC) is heterogeneous and known to be underestimated on small biopsies. Correlation of PD-L1 expression with clinicopathologic features may provide additional useful information. To our knowledge, the clinicopathologic features of NSCLC have not been reported for subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells.
Objective:
- To investigate the clinicopathologic characteristics of NSCLC subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells.
Design:
- PD-L1 immunohistochemistry with the SP142 clone was performed on whole-tissue sections and given semiquantitative scores (0/1/2/3) according to percent of PD-L1+ tumor cells (TCs) and percent tumor area with PD-L1+ tumor-infiltrating immune cells (ICs).
Results:
- Adenocarcinoma cases that were scored either TC 1/2/3 or IC 1/2/3 included most (22 of 34; 65%) high-histologic grade cases and most (25 of 36; 69%) solid subtype cases. Compared with the adenocarcinoma TC 0 and IC 0 subset, the TC 1/2/3 or IC 1/2/3 subset correlated with higher histologic grade (P = .005, χ2 test for trend) and solid subtype (P < .001, Fisher exact test). Compared with the adenocarcinoma TC 0/1 or IC 0/1 subset, the TC 2/3 or IC 2/3 subset correlated with higher histologic grade (P = .002, χ2 test for trend), solid subtype (P < .001, Fisher exact test), and higher smoking pack-years (P = .01, Mann-Whitney test).
Conclusions:
- Lung adenocarcinoma subsets defined by PD-L1 expression in either tumor cells or tumor-infiltrating immune cells correlated with high histologic grade, solid subtype, and high smoking pack-years.
