NLR & ALC as prognostic markers in patients treated with curative intent radiotherapy for NSCLC

Abstract

Purpose or Objective Neutrophil-Lymphocyte ratio (NLR) and absolute lymphocyte count (ALC) have been proposed as prognostic markers in non-small cell lung cancer (NSCLC). The objective of this study was to examine the association of NLR/ALC pre and post curative-intent radiotherapy (RT) for NSCLC on disease recurrence and overall survival. Materials and Methods A retrospective study of consecutive patients who underwent curative-intent RT for NSCLC across 9 sites in the UK from 01/10/2014 to 01/10/2016. A multivariate analysis was performed to assess the ability of pre-treatment NLR/ALC, post-treatment NLR/ALC and change in NLR/ALC, adjusted for co-founding factors using the Cox proportional hazards model, to predict disease recurrence and overall survival (OS) within 2 years of treatment. Results 425 patients were identified with complete blood parameter values. Higher pre-NLR, post-NLR and change in NLR plus lower post ALC were all independent predictors of worse survival. Receiver operator curve analysis found a pre-NLR >2.5 (OR 1.71, 95%CI 1.06-2.79, p< 0.05), a post-NLR >5.5 (OR 2.36, 95%CI 1.49-3.76, p< 0.001], a change in NLR >3.6 (OR 2.41, 95%CI 1.5-3.91, p<0.001) and a post-ALC <0.8 (OR 2.86, 95%CI 1.76- 4.69, p <0.001) optimally predicted poor overall survival on both univariate and multivariate analysis when adjusted for cofounding factors. None of the NLR/ALC parameters were independent predictors of disease recurrence. Conclusion NLR and ALC, surrogate markers for systemic inflammation, have prognostic value in NSCLC patients treated with curative intent radiotherapy. These simple and readily available parameters may have a future role in risk stratification post treatment to inform the intensity of surveillance protocols.