Prognostication of non-small cell lung cancer with concurrent chemoradiation treatment using neutrophil-to-lymphocyte ratio

Abstract

Purpose: We evaluated neutrophil-to-lymphocyte ratio (NLR) as a prognostic factor in patients with stage III unresectable non-small cell lung cancer (NSCLC) treated with concurrent chemoradiation (CRT). Furthermore, we examined neutrophil and lymphocyte changes to determine their contributions to NLR variation over time. Materials and Methods: A retrospective review was performed that included 262 patients diagnosed with stage III unresectable NSCLC from 2005 to 2020 who received concurrent CRT with a 60 Gy or 66 Gy in 30 fractions radiotherapy regimen. Pre-CRT NLR, lymphocyte nadir NLR, post-CRT NLR at 1 month +/- 2-week intervals up to 6 months relative to the end of CRT, and NLR fold-change were calculated. The primary endpoint was overall survival. Results: Of the examined parameters, high NLR had the most consistently high prognostic value for poorer outcomes for all 3 endpoints in the 6-month period post-CRT, with the highest hazard ratios (HRs) at 3 to 4 months. This was associated with a decrease in neutrophils from 3 to 4 months, while NLR and lymphocytes were relatively stable. Several other parameters at 4 months, including individual cell counts and NLR fold-change (relative to the lymphocyte nadir), were associated with high HRs for mortality. Conclusion: Our study suggests that a window of time at 3 to 4 months post-CRT exists for when NLR and related hematologic parameters demonstrate increased prognostic value. This period may represent an area for further investigation as a potential opportunity for risk stratification with possible implications for surveillance and treatment.