Programmed death ligand-1 expression in non-small cell lung cancer in a Western Australian population and correlation with clinicopathologic features
Document Type
Journal Article
Publication Title
Modern Pathology
ISSN
1530-0285
Volume
32
Issue
4
First Page
524
Last Page
531
PubMed ID
30401947
Publisher
Springer Nature Publishing AG
School
School of Medical and Health Sciences
RAS ID
31190
Abstract
Immune checkpoint inhibition is an important therapeutic option in patients with non-small cell lung cancer. Programmed cell death ligand-1 (PD-L1) expression may serve as a predictive marker for anti-PD-1/PD-L1 therapies. The relationship between non-small cell lung cancer PD-L1 expression and clinicopathological characteristics remains unclear and there is no population level Australian data. We report the results of PD-L1 testing in patients with non-small cell lung cancer diagnosed at major Western Australian public hospitals served by a single state Pathology provider. We analyzed PD-L1 expression by immunohistochemistry in 241 non-small cell lung cancer specimens using the 22C3 clone on a Dako autostainer platform. Tumor cell PD-L1 expression was scored as Tumor Proportion Score and categorized using pre-specified subsets of 1%, 1-49% and ≥ 50% for correlation with clinicopathologic features. PD-L1 Tumor Proportion Score was 1% in 65 (27%) cases, 1-49% in 100 (41%) cases and ≥ 50% in 76 (32%) cases. PD-L1-positive rate was 92% in squamous cell carcinomas and 67% in adenocarcinomas. PD-L1 Tumor Proportion Score was higher in squamous cell carcinomas (p = 0.004) and lower in adenocarcinomas (p = 0.003). Of the 196 non-squamous carcinomas, 35% had rat sarcoma viral oncogene homolog (RAS) mutations, 13% had epidermal growth factor receptor (EGFR) mutations, 2% had anaplastic lymphoma kinase (ALK) translocations and 2% had ROS1 translocations. Tumor Proportion Score ≥ 50% was seen in 34% (23/68), 28% (7/25) and 25% (1/4) of RAS, EGFR mutant, and ALK translocated carcinomas, respectively. There was no significant correlation between PD-L1 expression and molecular or genetic abnormalities, or other parameters including age, gender, stage, and smoking status. In our patient cohort, PD-L1 Tumor Proportion Score was significantly higher in squamous cell carcinomas and lower in adenocarcinomas. The overall prevalence of Tumor Proportion Score ≥ 50% is consistent with that reported in clinical trials.
DOI
10.1038/s41379-018-0173-9
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Comments
Ye, L., Leslie, C., Jacques, A., Ardakani, N. M., Amanuel, B., & Millward, M. (2019). Programmed death ligand-1 expression in non-small cell lung cancer in a Western Australian population and correlation with clinicopathologic features. Modern Pathology, 32(4), 524–531. Available here