Elevated preoperative neutrophil to lymphocyte ratio predicts survival following hepatic resection for colorectal liver metastases

BackgroundThe 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.DesignRetrospective 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 ≥ 5 was considered to be elevated.ResultsTwo 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).ConclusionElevated 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.