Prognostic value of neutrophil-to-lymphocyte ratio in colorectal cancer liver metastasis: A meta-analysis of results from multivariate analysis

We aimed to evaluate the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in colorectal cancer liver metastasis (CRLM). A comprehensive search was conducted across PubMed, MedLine, and the Cochrane Library databases for articles published from January 1, 2000 to April 30, 2022 that investigated the long-term prognostic value of NLR in CRLM; only studies with multivariate analyses were enrolled. Hazard ratio (HR) with 95% confidence interval (CI) was used to determine the effect size. A total of 2,522 patients in 12 studies were selected; the meta-analysis demonstrated that elevated NLR correlated with poor overall survival (OS) and disease-free survival (DFS) (HR, 1.95, 95%CI, 1.698-2.223, P < 0.01; HR, 1.80, 95%CI, 1.363-2.363, P < 0.01; respectively). The 5-year OS and disease-free survival rates were higher in the patients with normal NLR than in patients with high NLR (47% vs. 27%, P < 0.01; 37% vs. 6%, P < 0.01, respectively). Further analysis of clinicopathological parameters indicated no significant difference between the patients with and without elevated NLR. Begg's and Egger's tests for publication bias revealed no significant publication bias (P = 0.891 and P = 0.926, respectively). Multivariate analysis revealed that NLR had an excellent prognostic ability in CRLM, which can be used in deciding the treatment and predicting the clinical outcomes. Further multicenter randomized controlled trials are required to verify this conclusion.