Background: The neutrophil-lymphocyte ratio (NLR) provides an indicator of inflammatory status. An elevated NLR has been shown to be a prognostic indicator in primary colorectal malignancy. The aim of this study was to establish whether NLR predicts outcome in patients undergoing resection for colorectal liver metastasis.
Design: Retrospective analysis of the white cell and differential counts for 440 patients undergoing liver resections for colorectal liver metastasis between January 1996 and January 2006. An NLR > or = 5 was considered to be elevated.
Results: Two hundred and eighty-nine males and 151 females were included. Seventy-eight patients (18%) had an elevated NLR, 55 of whom died, giving elevated NLR a positive predictive value (PPV) for death of 71%. Sixty of the 78 patients had recurrent disease giving raised NLR an PPV for recurrence of 78%. The 5-year survival for patients undergoing resection with high NLR was significantly worse than that for patients with normal NLR (22% vs. 43%, p<0.0001). Univariate analysis of factors affecting survival revealed raised NLR, number of metastases > 8, tumour size > 5 cm and age > 70 significantly affected outcome. All factors except tumour size remained significant predictors of term survival on multivariate analysis (NLR:HR=2.261, CI=1.654-3.129, p<0.0001, metastases > 8:HR=1.611, CI=1.006-2.579, p=0.047, age > 70:HR=1.418, CI=1.049-1.930, p=0.027). Elevated NLR was found to be the sole positive predictor of recurrence on univariate analysis (HR=4.521, CI=2.475-8.257, p<0.0001).
Conclusion: Elevated NLR increases both risk of death and the risk of recurrence in patients who undergo surgery for CRLM. Preoperative NLR measurement may therefore provide a simple method of identifying patients with a poorer prognosis.