P1.05-034 Neutrophil-To-Lymphocyte and Platelet-To-Lymphocyte Ratios as Prognostic Biomarkers in Early NSCLC Patients Treated with SABR

Abstract

Inflammation may play an important role in cancer progression. High Neutrophil-to-Lymphocyte ratio (NLR) and Platelet-to-Lymphocyte ratio (PLR) have been reported to be poor prognostic indicators in several malignancies. In this study we quantify the prognostic impact of these biomarkers for overall survival (OS) among early stage NSCLC patients treated with Stereotactic Ablative Body Radiotherapy (SABR). 102 consecutive patients who received SABR between October 2011 and May 2014 at the Beatson West of Scotland Cancer Centre (BWoSCC) were identified from a prospectively maintained electronic database. NLR and PLR were derived from blood results obtained within 60 days prior to SABR. Receiver Operator Characteristic (ROC) curves were generated to calculate the optimal thresholds for NLR and PLR. The median age of patients was 72 (range 47-91) years. 60 (59%) were female. Maximum tumor diameter ranged from 10-42mm (median 18mm). Median follow up was 37.1 months. Overall survival at 2 and 4 years was 75.5% (95% CI 65.9-82.7%) and 51.4% (38.8-62.6%) respectively. There was strong association between NLR and PLR levels (r=0.803, p<0.001). ROC Curves indicated a threshold value for NLR of 3.155 (AUC 0.74) and PLR of 155.15 (AUC 0.70) respectively. Median OS for ‘low’ NLR and PLR was not yet reached compared with 33.9 months for ‘high’ NLR (p<0.0001) and 35.4 months for ‘high’ PLR (p=0.002). Multi-variable analysis indicated a stronger independent effect of NLR (p<0.0001), whilst taking account of gender, age, tumor size, histological confirmation and performance status. No association was found between elevated NLR or PLR and loco-regional or distant recurrence. Neutrophil-to-Lymphocyte Ratio appears to be a prognostic biomarker for patients with early stage NSCLC receiving SABR. Platelet-to-Lymphocyte ratio acts as a linear co-variant. We found no association between elevated NLR or PLR and loco-regional or distant recurrence.