Prognostic Significance of Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Oncologic Outcomes of Esophageal Cancer: A Systematic Review and Meta-analysis.

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been reported to predict oncologic outcomes in patients with various types of cancer. However, their prognostic value in patients with esophageal cancer is unclear. In this meta-analysis, we evaluated the prognostic significance of NLR and PLR in esophageal cancer patients.

METHODS

We performed comprehensive searches of electronic databases to identify studies that evaluated the prognostic impact of pretreatment NLR and PLR in esophageal cancer patients. The end points were overall survival (OS), disease-free survival, and clinicopathologic parameters. A meta-analysis using random-effects models was performed to calculate hazard ratios (HRs) or odds ratios with 95 % confidence intervals (CIs).

RESULTS

Seven retrospective, observational, cohort studies involving 1540 patients were included. All seven studies evaluated NLR, and four evaluated PLR. Both high NLR (HR 1.40, 95 % CI 1.08-1.81, P = 0.01) and high PLR (HR 1.59, 95 % CI 1.14-2.21, P = 0.006) were significantly predictive of poorer OS. NLR was not a significant predictor of disease-free survival. High PLR (HR 1.85, 95 % CI 1.50-2.28, P < 0.00001) but not NLR was significantly predictive of poorer OS in a subgroup of patients who underwent curative surgery without neoadjuvant chemoradiation. Both high NLR and high PLR were significantly associated with deeper tumor invasion and lymph node metastasis.

CONCLUSIONS

NLR and PLR are associated with tumor progression and are predictive of poorer survival in patients with esophageal cancer. These ratios may thus help to inform treatment decisions and predict treatment outcomes.