Pre-Treatment and Post-Treatment Neutrophil-to-Lymphocyte Ratio Predict Pathological Tumor Response and Survival in Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy

OBJECTIVE The aim of this study is to investigate the relationship between baseline and post-treatment neutrophil-to-lymphocyte ratio (NLR) levels and response to neoadjuvant chemoradiotherapy (CRT) in terms of good pathological response and survival. METHODS Fifty-six patients who underwent neoadjuvant CRT and curative surgery for locally advanced rectal cancer (LARC) were analyzed retrospectively. Pre-CRT and post-CRT hematologic parameters were recorded. The link between NLR and clinical outcomes was explored. RESULTS The receiver operating characteristic analysis revealed appropriate cut-off values of 2.87 for pre-CRT NLR associated with good pathological response and 8.68 for post-CRT NLR predicting survival. The low pre-CRT NLR group had better outcomes in terms of good pathological response compared to the high pre-CRT NLA group (OR 4.15, 95% CI 1.23-13.76, p=0.021). However, the analysis failed to show the correlation between NLR and pCR (OR 2.74, 95% CI 0.37-20.15, p=0.320). Patients with elevated post-CRT NLR had significantly worse 5-year overall survival (OS), disease-free survival (DFS) and local regional recurrence-free survival (LRRFS) rates compared to low post-CRT NLR in multivariate analysis (46.6% vs. 74.4%, p=0.020; 35.3% vs. 71.9%, p=0.018; 40.8% vs. 78.1%, p=0.006). CONCLUSION High pre-CRT NLR might be used as a poor pathological tumor response predictor in LARC patients treated with neoadjuvant CRT. In addition, low post-CRT NLR is associated with favorable OS, DFS, and LRRFS. Therefore, easily accessible and cost-effective NLR can be considered as a potential predictive marker to identify patients and establish personalized treatment strategies.