Neutrophil-to-lymphocyte ratio predicts survival of patients with rectal cancer receiving neo-adjuvant chemoradiation followed by radical resection: a meta-analysis

Background: Neutrophil-to-lymphocyte ratio is suggested as a prognostic and predictive factor for patients with rectal cancer. The purpose of the current meta-analysis is to evaluate the relationship between neutrophil-lymphocyte ratio (NLR) and the outcome of patients, with rectal cancer receiving chemoradiation and surgery. Methods: A systematic review on two databases and a selection of studies were done. Thereafter, two meta-analyses were performed, evaluating the relationship of baseline NLR with overall survival (OS) and disease-free survival (DFS). Results: Thirty-one retrospective studies were selected. Twenty-six studies have documented a significant relationship of NLR to OS (HR 2.05, CI 1.66-2.53), whereas 23 studies have reported a weaker but significant relationship of NLR to DFS (HR 1.78, CI 1.49-2.12). Among the moderator variables, a possible effect for age and sex on the relationship of NLR with DFS is suggested. Conclusions: Baseline NLR >3 is a simple and reproducible prognostic factor, with a more consistent effect in the elderly. It could be a reliable variable to support clinicians in defining personalized treatment strategies, even though a standardization of the cutoff and a better characterization among microsatellite unstable rectal tumors are necessary.