The prognostic value of neutrophil-to-lymphocyte ratio in patients with epidermal growth factor receptor mutated advanced non-small cell lung cancer (NSCLC).

Abstract

e21675 Background: An elevated neutrophil-to-lymphocyte ratio (NLR) indicates a poor prognosis across multiple cancers, including non-small cell lung cancer (NSCLC). Our study aims to validate these findings in EGFR-mutated NSCLC patients receiving tyrosine kinase inhibitor (TKI) therapy, and to evaluate other factors that may impact NLR. Methods: We retrospectively analyzed 95 patients with advanced EGFR-mutated NSCLC treated with TKIs at Rush University Medical Center and The University of Chicago Medical Center from August 2011 to August 2018. The prognostic value of NLR was assessed at the start of therapy, and after 6 and 12 weeks of treatment. The median progression free survival (mPFS) and median overall survival (mOS) were calculated by the Kaplan-Meier method and compared with the log rank test. Spearman rank correlation was used to correlate number of disease sites with NLR at diagnosis. T test analysis compared mean NLR between patients with high grade (≥ 3) toxicity versus low or no (grades 0-2) toxicity. The relationship between NLR and body mass index (BMI) changes were analyzed using Pearson correlation. Results: At therapy start, patients with NLR < 5 (n = 57) had a mPFS of 15.3 months and a mOS of 56.7 months, while those with NLR ≥ 5 (n = 35) had a mPFS of 13.8 months ( p= 0.024) and mOS of 40.0 months ( p= 0.0056). After 6 weeks of treatment, patients with NLR < 5 (n = 69) had a mPFS of 14.6 months and mOS of 56.2 months, while those with NLR ≥ 5 (n = 23) had a mPFS of 10.0 months ( p= 0.052) and a mOS of 37.74 months ( p= 0.049). After 12 weeks of treatment, patients with NLR < 5 (n = 66) had a mPFS of 14.2 months and mOS of 54.8 months, while those with NLR ≥ 5 (n = 17) had a mPFS of 3.0 months ( p= 0.0016) and a mOS of 22.4 months ( p= 0.0012). Patients who had a decrease in NLR did not have significantly better mPFS or mOS compared to patients whose NLR increased at either 6 or 12 weeks. Baseline number of disease sites and BMI did not correlate with NLR at diagnosis. Changes in BMI did not correlate with a change in NLR at 6 weeks or at 12 weeks. There was no significant difference in NLR between patients with high grade (≥ 3) versus no or low grade (0-2) drug toxicities. Conclusions: NLR can be used as a prognostic factor to predict which EGFR mutated NSCLC patients on TKI therapy may have worse PFS or OS outcomes. Closer monitoring and potential therapeutic escalation may be beneficial in patients with elevated NLR ≥ 5. Further work studying NLR in patients being treated with a larger osimertinib cohort is ongoing.