Ratios derived from an array of standard haematological indices predict the oncological outcome in colon cancer

Aim The interaction between inflammation and cancer is well established. Surrogate markers of systemic inflammation, such as the neutrophil/lymphocyte ratio (NLR), may be associated with the long-term oncological outcome. The present study aimed to characterize the relationship between several ratios derived from haematological indices using a classification and regression tree analysis. Method Haematological white-cell ratios were established for all patients undergoing colonic cancer resection with curative intent (n = 436) in a regional cancer centre. The optimal ratios associated with overall survival (OS) were established in a training set (n = 386) using a classification and regression tree (CRT) technique. The association between ratios and OS was assessed in a separate test set (n = 50). Within the test set, two groups were generated based on each ratio (one group above and one group below the cut-off value identified in the training set). The association between ratios and OS was assessed using a stepwise Cox proportional-hazards regression model. Results The following ratios, identified by the CRT, were associated with adverse OS in the test set: an NLR of ≥ 3.4 [hazard ratio (HR) = 3.4, P < 0.001]; and a white-cell-count/lymphocyte ratio (WLR) of ≥ 5.28 (HR = 4.1, P = 0.03). Conclusion This is the first study to apply recursive partitioning in determining the relationship between haematological ratios and OS in colon cancer. Haematological ratios were predictive of oncological outcome. What does this paper add to the literature? This study suggests an association between systemic inflammation and oncological outcome.