Stage-dependent changes of preoperative neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in colorectal cancer

This study aims to assess the association of the preoperative neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) with tumor stage in colorectal cancer (CRC) patients. A retrospective study was performed in 336 CRC patients. Preoperative whole blood counts, serum levels of carcinoembryonic antigen (CEA), and clinicopathologic data were collected. The correlations between laboratory parameters and the tumor, node, and metastasis (TNM) stages were analyzed. The clinicopathologic TNM stages among CRC patients were 12.8 % at stage I, 32.4 % at stage II, 44.6 % at stage III, and 10.1 % at stage IV. NLR, PLR, and CEA levels were higher in CRC patients compared to healthy controls (all P < 0.0001). Both NLR and PLR showed an early elevation as compared to CEA, with a higher area under curve (AUC) value (0.71 vs. 0.62) in predicting the presence of the tumor with stage I/II. Accordingly, significant elevations of NLR (P = 0.0018) and PLR (P < 0.0001) were firstly detected in stage I and stage II, respectively. In addition, NLR exhibited a second phase elevation in stage IV, with a significant higher level in M1 subgroup compared to M0 subgroup (P = 0.022). While PLR showed a T stage-dependent increase (P = 0.0003) and was identified as an independent factor for the T grade development (P < 0.0001). Our data indicated that both neutrophil- and platelet-mediated inflammatory reactions are predominantly involved in the different stages of CRC development. Determination of pretreatment levels of NLR and PLR might provide useful information for the early diagnosis or the therapeutic choices in CRC patients.