Clinical significance of pre-operative neutrophil lymphocyte ratio and platelet lymphocyte ratio as prognostic factors for patients with colorectal cancer

The present study aimed to investigate the independent prognostic values of the pre-operative neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) in patients with colorectal cancer (CRC). The present study retrospectively analyzed the data of 216 patients with CRC from a single hospital. The clinicopathological characteristics of the patients were compared and prognostic factors were evaluated. NLR and PLR were associated with tumor differentiation status and the tumor diameter, respectively, and PLR was also associated with the primary tumor classification (T classification). Furthermore, NLR and PLR were positively associated with each other (R-2=0.5368; P<0.0001). Univariate analyses indicated that stage II and III patients with a high NLR (4.98; P<0.001) or PLR (246.36; P<0.001) possessed a significantly poorer 5-year OS rate compared with those with a low NLR or PLR. Post-operative adjuvant chemotherapy improved the 5-year OS rate in patients with a high NLR or PLR. Multivariate analyses indicated that NLR and PLR were independent prognostic factors [NLR, relative risk (RR)=4.074 and P<0.001; PLR, RR=2.029 and P=0.029] in patients with CRC, and were associated with the T classification, lymph node metastasis and post-operative adjuvant chemotherapy response of patients. Additionally, the area under the curve (AUC) was 0.748 for NLR (95% CI, 0.684-0.804; P<0.0001) and 0.690 for PLR (95% CI, 0.623-0.751; P<0.0001). The RR and AUC indicated that NLR was the superior predictive factor in patients with CRC. In conclusion, the pre-operative NLR and PLR were significant independent prognostic factors in patients with CRC, and NLR was more effective as a prognostic marker compared with PLR. Adjuvant chemotherapy appeared to be more effective in CRC patients with a higher NLR or PLR.