Prognostic utility of neutrophil-to-lymphocyte ratio in patients with metastatic colorectal cancer treated using different modalities

Abstract

Introduction: Inflammation is a critical component in carcinogenesis. The neutrophil-to-lymphocyte ratio (nlr) has been retrospectively studied as a biomarker of prognosis in metastatic colorectal cancer (mcrc). Compared with a low nlr, a high nlr is associated with worse prognosis. In the present study, we compared real-world survival for patients with mcrc based on their nlr group, and we assessed the utility of the nlr in determining first-line chemotherapy and metastasectomy benefit.

Methods: In this retrospective and descriptive analysis of patients with mcrc undergoing first-line chemotherapy in a single centre, the last systemic absolute neutrophil and lymphocyte count before treatment was used for the nlr. A receiver operating characteristic curve was used to estimate the nlr cut-off value, dividing the patients into low and high nlr groups. Median overall survival (mos) was compared using Kaplan-Meier curves and the log-rank test. A multivariate analysis was performed using a Cox regression model.

Results: The 102 analyzed patients had a median follow-up of 15 months. Regardless of systemic therapy, approximately 20% of patients underwent metastasectomy. The nlr cut-off was established at 2.35, placing 45 patients in the low-risk group (nlr < 2.35) and 57 in the high-risk group (nlr ≥ 2.35). The Kaplan-Meier analysis showed a mos of 39.1 months in the low-risk group and 14.4 months in the high-risk group (p < 0.001). Multivariate Cox regression on the nlr estimated a hazard ratio of 3.08 (p = 0.01). Survival analysis in each risk subgroup, considering the history of metastasectomy, was also performed. In the low-risk group, mos was longer for patients undergoing metastasectomy than for those not undergoing the procedure (95.2 months vs. 22.6 months, p = 0.05). In the high-risk group, mos was not statistically different for patients undergoing or not undergoing metastasectomy (24.3 months vs. 12.7 months, p = 0.08).

Conclusions: Our real-world data analysis of nlr in patients with mcrc confirmed that this biomarker is useful in predicting survival. It also suggests that nlr is an effective tool to choose first-line treatment and to predict the benefit of metastasectomy.

Keywords: Colorectal cancer; lymphocytes; metastasectomy; metastatic; neutrophils; nlr.

FIGURE 1

Receiver operating characteristic curve analysis of the neutrophil-to-lymphocyte ratio in patients with metastatic colorectal cancer. Area under the curve: 0.640; 95% confidence interval: 0.53 to 0.75; p = 0.016.

FIGURE 2

Kaplan–Meier survival analysis. Overall population survival was significantly worse in patients with a high neutrophil-to-lymphocyte ratio (NLR), p = 0.001.

FIGURE 3

Kaplan–Meier survival analyses by risk group and history of metastasectomy. (A) In the low-risk group [neutrophil-to-lymphocyte ratio (NLR) < 2.35], median overall survival was longer for patients receiving than not receiving metastasectomy (p = 0.05). (B) In the high-risk group (NLR ≥ 2.35), median overall survival was nonsignificantly different for patients receiving and not receiving metastasectomy (p = 0.08).

FIGURE 4

Kaplan–Meier survival analyses by risk group and history of metastasectomy combined. Median overall survival was similar for patients with low-risk disease and no metastasectomy and for those with high-risk disease who also received metastasectomy (p = 0.01).