The value of the pretreatment neutrophil lymphocyte ratio vs. platelet lymphocyte ratio in predicting the long-term survival in colorectal cancer.

BACKGROUND: The neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) have been well studied as inflammatory markers and predictors for outcomes in colorectal cancer patients. Our aim was to determine the predictive value of both above ratios in colorectal cancer patients.

METHODS: This is a longitudinal retrospective study of a prospectively maintained database, included 580 patients, who had a complete blood count recorded before treatment (surgery or chemotherapy). We excluded patients presented with obstruction, infection, active hematological disease or those receiving steroid. The primary outcome (4-year cancer-related mortality) was obtained from our cancer registry.

RESULTS: The 4-year cancer-related mortality rate in the 3rd tertile of NLR was 37% in comparison with 13% and 19% in lower tertiles, P value < 0.001. Similarly the 3rd tertile of PLR was 32% with 18% and 19% in lower tertiles, P value < 0.0005. In the multivariate survival analyses, elevated NLR was associated with higher mortality (a hazard ratio of 2.31(1.4-3.8) for the highest tertile and 5% increase in mortality for each unit increase in NLR, p < 0.001). Similarly, elevated NLR was a significant predictor for a worse disease-free survival. However, PLR was not significant predictor of mortality when adjusted for other confounding variables.

CONCLUSION: Elevated pretreatment NLR is an independent predictor of both worse overall and disease free survival in colorectal cancer, whereas PLR was not after adjusting for confounding variables.