Background: The preoperative ratio of neutrophils to lymphocytes (NLR) and platelets to lymphocytes (PLR) have been proposed as markers of poor outcome in colorectal cancer (CRC) patients. Aim of our study to investigate the prognostic significance of both PLR and NLR on colorectal cancer survival. We also aimed to investigate the prognostic utility of a combined PLR-NLR score in large cohort of stages I-IV CRC patients.

Methods: Data on 899 patients, who were operated at the Northern Health District Hospitals between 2006 and 2009, were drawn from a prospectively recorded registry. Optimal cut off points for NLR and PLR was calculated using the R ‘maxstat’ package. Analyses of survival involved the Kaplan-Meier method and Cox regression.

Results: Increased NLR and PLR separately were independently associated with diminishing overall survival after adjustment for other prognostic variables (HR 0.414, 95% CI 0.310-0.554, p < 0.001 and HR 0.592, 95% CI 0.452-0.775, p<0.001 respectively). Combination of NLR and PLR is also showed to be a useful predictor of postoperative survival in patients with CRC by bivariate and multivariate analysis.

Conclusion: In CRC patients with stage I-IV tumor the significant association between NLR, PLR and combination of NLR/PLR and overall mortality was demonstrated. This result indicates that CRC patients with an elevated inflammatory status preoperatively were likely to progress to earlier death.