Prognostic value of neutrophil to lymphocyte ratio in lung metastasectomy for colorectal cancer.

Abstract

Neutrophil to lymphocyte ratio (NLR) has been shown to be a promising biomarker in several cancers. Prognostic biomarkers are still needed to define good candidates for lung metastasectomy for colorectal cancer. We aimed to evaluate the role of NLR. Data from 574 patients who underwent lung metastasectomy for colorectal cancer in 3 departments of thoracic surgery from 2004 to 2014 were retrospectively reviewed. Overall survival (OS) and the time to pulmonary recurrence (TTPR) were the main end points. Correlations between NLR and OS (R2 = 0.53), and NLR and TTPR (R2 = 0.389) were significant (P < 0.0001 for both), with corresponding Pearson R of -0.728 (P < 0.0001) and -0.624 (P < 0.0001), respectively. A receiver operating characteristic curve analysis highlighted an NLR cut-off value of 4.05 as the best predictor of OS and TTPR. NLR ≤4.05 was observed in 238 patients (41.4%). In the univariable analysis, the median OS was 117 months for patients with NLR ≤4.05 and decreased to 40 months for patients with NLR >4.05 (P < 0.0001). The median TTPR reached 52 months in case of NLR ≤4.05 and decreased to 12 months in patients with NLR >4.05. In the multivariable analysis, NLR ≤4.05 remained an independent favourable prognostic factor on both OS [hazard ratio [HR] 0.29, 95% confidence interval (CI) 0.167-0.503; P < 0.0001] and TTPR (HR 0.346, 95% CI 0.221-0.54; P < 0.0001). Significant correlations between NLR >4.05 and KRAS (Cramer's V = 0.241, P < 0.0001) and BRAF (Cramer's V = 0.153, P = 0.003) mutations were observed. NLR is a simple and powerful predictor of outcomes in patients undergoing pulmonary metastasectomy for colorectal cancer.