The prognostic value of preoperative NLR, d-NLR, PLR and LMR for predicting clinical outcome in surgical colorectal cancer patients

Accumulating evidences indicate cancer-triggered inflammation plays a pivotal role in carcinogenesis. Systematic inflammatory response biomarkers are considered as potential prognostic factors for improving predictive accuracy in colorectal cancer (CRC). Preoperative neutrophil-to-lymphocyte ratio (NLR), derived neutrophilto-lymphocyte ratio (d-NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR) were investigated and compared in 205 surgical CRC patients. ROC curve was applied to determine thresholds for four biomarkers, and their prognostic values were assessed using Kaplan-Meier curve, univariate and multivariate COX regression models. Moreover, a number of risk factors were used to form nomograms for evaluating risk of survival, and Harrell's concordance index (c-index) was used to evaluate predictive accuracy. Results showed that elevated NLR was significantly associated with diminished recurrent-free survival (RFS), overall survival (OS) and cancer-specific survival (CSS) in surgical CRC patients. Moreover, multivariate COX analysis identified elevated NLR as an independent factor for poor RFS (P < 0.001, HR 2.52, 95 % CI 1.65-3.83), OS (P < 0.001, HR 2.73, 95 % CI 1.74-4.29) and CSS (P < 0.001, HR 2.77, 95 % CI 1.72-4.46). Additionally, predictive nomograms including NLR for RFS, OS and CSS could be more effective in predicting RFS (c-index: 0.810 vs. 0.656), OS (c-index: 0.809 vs. 0.690) and CSS (c-index: 0.802 vs. 0.688) in surgical CRC patients, respectively. These findings indicate that preoperative elevated NLR can be considered as an independent prognostic biomarker for RFS, OS and CSS. Nomograms containing NLR provide improved accuracy for predicting clinical outcomes in surgical CRC patients under surgery resection.