Second and later-line erlotinib use in non-small cell lung cancer: real world outcomes and practice patterns overtime in Canada

Kirstin Perdrizet; Rinku Sutradhar; Qing Li; Ning Liu; Craig C Earle; Natasha B Leighl

doi:10.21037/jtd-21-804

Second and later-line erlotinib use in non-small cell lung cancer: real world outcomes and practice patterns overtime in Canada

J Thorac Dis. 2021 Sep;13(9):5419-5429. doi: 10.21037/jtd-21-804.

Authors

Kirstin Perdrizet^{1

2

3

4}, Rinku Sutradhar^{4

5

6}, Qing Li⁵, Ning Liu⁵, Craig C Earle^{3

5

7}, Natasha B Leighl^{1

3

4}

Affiliations

¹ Department of Oncology and Hematology, Princess Margaret Cancer Centre/University Health Network, Toronto, Canada.
² Division of Oncology, William Osler Health System, Brampton, Canada.
³ Department of Medicine, University of Toronto, Toronto, ON, Canada.
⁴ Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada.
⁵ ICES (formerly the Institute for Clinical and Evaluates Sciences), Toronto, Canada.
⁶ Department of Biostatistics, Dalla Lana School of Public Health at the University of Toronto, Toronto, Canada.
⁷ Department of Oncology and Hematology, Sunnybrook Health Sciences Centre, Toronto, Canada.

Abstract

Background: In Canada, epidermal growth factor receptor (EGFR) inhibitor therapies in advanced non-small cell lung cancer (NSCLC) were initially approved regardless of EGFR status. The purpose of this study is to characterise the use of second or later-line erlotinib therapy in Ontario, Canada from 2007-2016, as well as evaluate the impact of erlotinib therapy on survival and emergency department (ED) visits in a real-world population.

Methods: This is a retrospective cohort study derived at ICES (formerly known as the Institute for Clinical and Evaluative Sciences) of advanced NSCLC patients diagnosed from 2007-2016 in Ontario, Canada, over the age of 65, who received at least one dose of first-line chemotherapy. The exposure of interest was receipt of second or later-line erlotinib. The primary outcome was the hazard ratio for mortality evaluated using a Cox proportional hazards model, and the secondary outcome, ED visits, was evaluated using a Poisson model.

Results: First-line chemotherapy was administered in 30.4% of stage IV NSCLC patients. Of these patients, 19.7% received second or later-line erlotinib. The proportion of patients prescribed second or later-line erlotinib decreased over the course of the study (P<0.0001). Unadjusted median overall survival in the entire cohort was 325 days (95% CI: 314-337 days), 513 days (95% CI: 485-539 days) in the erlotinib cohort, and 282 days (95% CI: 270-291 days) in the non-erlotinib cohort. Despite this, the adjusted hazard ratio for death was 1.89 (95% CI: 1.73-2.07, P<0.0001) for patients on erlotinib. Patients receiving erlotinib also had a marginally higher relative rates of ED visits with an adjusted relative risk of 1.10 (95% CI: 1.02-1.19, P=0.013).

Conclusions: This study highlights the importance of using EGFR targeted treatments in NSCLC patients with a predictive biomarker, and suggests that treatment with erlotinib therapy is unlikely to benefit unselected patients with advanced NSCLC.

Keywords: Lung cancer; biomarkers; erlotinib; real-world data.