Objectives
To describe programmed cell death ligand-1 (PD-L1) testing patterns and results among patients with metastatic non-small cell lung cancer (NSCLC) in the United States (US), United Kingdom (UK), Germany, Spain, and Canada.
Methods
Physicians provided a retrospective medical record review of patients diagnosed with metastatic NSCLC from January 2011 to March 2016. Patient characteristics and PD-L1 testing at initial diagnosis were descriptively assessed.
Results
Data were abstracted from 204 US, 206 UK, 212 German, 205 Spanish, and 55 Canadian patients. The majority of patients were male (US, 63.2%; UK, 60.7%; Germany, 69.3%; Spain, 75.1%; Canada, 65.5%). Most were initially diagnosed with stage IV disease (US, 74.5%; UK, 82.0%; Germany, 88.7%; Spain, 83.4%; Canada, 43.6%); the remaining presented initially with earlier stage disease and subsequently developed metastases. Distant lymph node metastases were observed in 32.6% (US), 33.3% (UK), 21.9% (Germany), 30.3% (Spain), and 36.4% (Canada) of patients. In each country, approximately 90% of patients were current or former smokers. PD-L1 testing at initial diagnosis occurred in 34.3% (US), 27.2% (UK), 31.6% (Germany), 17.1% (Spain), and 34.6% (Canada) of patients. Among these patients, 55.7% (US), 62.5% (UK), 37.3% (Germany), 48.6% (Spain), and 26.3% (Canada) tested positive. The mean (SD) percent of tumor cells staining for PD-L1 was 33.9% (34.3) in the US, 31.1% (31.1) in the UK, 16.7% (24.0) in Germany, 17.2% (23.5) in Spain, and 33.1% (21.7) in Canada. The Dako assay was used most often in the UK, while “other/not specified” was most frequently reported in the US and Canada. Physicians in Germany and Spain did not report which assay they used most often.
Conclusions
Despite similar distributions of risk factors (e.g., smoking history, nodal disease, stage IV disease) for elevated PD-L1 expression across countries and the recent introduction of highly effective anti-PD-L1 agents, PD-L1 testing rates remain low.
Article