The neutrophil-to-lymphocyte ratio as a predictor for recurrence of colorectal liver metastases following radiofrequency ablation

The purpose of this study was to assess the value of the neutrophil-to-lymphocyte ratio (NLR) as a predictive factor for recurrence of colorectal liver metastases following radiofrequency ablation (RFA) treatment. We retrospectively analyzed clinical data from 98 patients who received routine RFA treatment for colorectal liver metastases. Univariate analyses were conducted to evaluate the effects of preoperative maximum tumor diameter, number of tumors, colon cancer staging, carcinoembryonic antigen levels, and preoperative and postoperative NLRs on disease-free survival (DFS). Statistically significant factors were further analyzed using multivariate Cox regression models to identify independent factors that were predictive of tumor recurrence. The one-, three-, and five-year DFS rates for patient were 66.3, 28.6, and 17.3 %, respectively. Univariate analysis showed that preoperative NLR ≥ 2.5 and postoperative increase in NLR were associated with decreased DFS rates. One-, three-, and five-year DFS rates for patients with preoperative NLR ≥ 2.5 were 53.3, 20.0, and 11.1 %, whereas patients with preoperative NLR < 2.5 had DFS rates of 77.4, 35.8, and 22.6 %, respectively (P = 0.044). One-, three- and five-year DFS rates for patients with NLRs increased 1 month after RFA treatment were 52.3, 17.1, and 8.6 %, while patients with no increased postoperative NLRs had DFS rates of 73.0, 34.9, and 22.2 %, respectively (P = 0.022). Cox regression analysis showed that postoperative NLR increase was an independent risk factor (P = 0.029) for recurrence after RFA treatment in patients with colorectal liver metastases. The present study suggests that patients with preoperative NLRs ≥ 2.5 or increased postoperative NLR are at an increased risk for recurrence after RFA treatment for colorectal liver metastases.