Translational relevance of baseline NLR and LMR ratio in predicting response of EGFR-TKI.

Abstract

e15020 Background: Neutrophil-Lymphocyte Ratio (NLR) and Lymphocyte-Monocyte Ratio (LMR) have been under scrutiny for their potential as a prognostic tool in various cancers. While there have been conflicting opinions on their reliability, NLR has shown rather near accurate predictions in previous studies. Targeted tyrosine kinase inhibitors have shown good results in improving OS and PFS of patients with EGFR-mutated NSCLC but the prognostic indicators are limited. This study aims to decipher if baseline NLR and LMR ratios are valid tools to predict prognosis of patients with EGFR-mutated NSCLC. Methods: We analyzed 78 advanced NSCLC patients harboring Exon 19 Deletion and Exon 21 L858R mutation undergoing EGFR-TKI therapy. Baseline NLR and LMR were measured in peripheral blood within two weeks prior to the initiation of TKIs. Overall survival was used as an outcome measure for TKI therapy and it is defined as from the initiation of TKIs to death by any cause. The cut-off for NLR and LMR was calculated using an X-tile plot (version 3.6.1, Yale University, New Haven, CT, USA) by dividing marker data into three populations: low, middle, and high (i.e., two divisions), with randomized 1:1 “training” and “validation” cohorts. Results: Overall median survival of the study group was 31.5 months and median age was found to be 60 years. Gefitinib (35.9%) and afatinib (34.6%) were the most commonly prescribed followed by erlotinib (21.8%) and osimertinib (7.7%). With cut-points of 1.8 and 4.9 we analyzed three populations for baseline NLR as ≤1.8, 1.9-4.9 and > 4.9. Similarly, for LMR cut-points of 3.49 and 5 were found and we analyzed patients with LMR of ≤3.49, 3.5-5 and >5. There was a statistically significant overall median survival observed as per the obtained NLR as well as LMR cut-off as given in the table. Conclusions: A statistically significant co-relation was observed with baseline NLR and LMR ratio in predicting response to EGFR TKIs in NSCLC. Our study further strengthens the concept of using NLR and LMR as peripheral blood biomarkers for prognostic assessment in cancer patients undergoing treatment.[Table: see text]