Neutrophil-Lymphocyte Ratio is a Simple and Novel Biomarker for Prediction of Survival after Radioembolization for Metastatic Colorectal Cancer

Previous studies have reported that an elevated preoperative Neutrophil-Lymphocyte Ratio (NLR) is associated with poor prognosis in patients with various solid tumors including colorectal cancer (CRC). Here, we examine whether NLR predicts survival in patients with unresectable CRC metastases undergoing hepatic radioembolization. A retrospective review of 104 consecutive patients with unresectable metastatic CRC who were treated with radioembolization after failing first and second-line chemotherapy. Between 2002 and 2012, the median NLR for all patients was 4.6. Using receiver operating curve analysis, there was no difference between using an NLR cut-off of 4.6 or 5. Forty-eight patients had a high NLR of a parts per thousand yen5 and 56 patients had an NLR of < 5. Patients in both groups had similar previous extensive chemotherapy and liver-directed interventions. The median survival of patients with high NLR was 5.6 months (range 4.9-7.9 months) compared with 10.6 months (range 8.3-17.0 months) for patients with low NLR; a significant difference was found in overall survival (log-rank test; p = 0.001). Other factors associated with risk of death were extrahepatic spread of disease, presence of pulmonary nodules, previous liver-targeted intervention, and radiographic response. On multivariate analysis, high NLR, progressive radiographic response, and presence of extrahepatic disease remained independently associated with increased risk of death. NLR is a simply attainable, inexpensive, and useful biomarker to predict outcome in patients with metastatic colorectal cancer receiving radioembolization.