The Prognostic roles of platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio in gastrointestinal stromal tumours: a meta-analysis

Background: The platelet-to-lymphocyte ratio (PLR) and neutrophil-to- lymphocyte ratio (NLR) have been found to be associated with prognosis in several solid tumours. However, the prognostic roles of PLR and NLR in gastrointestinal stromal tumours (GISTs) remain controversial. The aim of this meta-analysis was to assess the prognostic roles of PLR and NLR in GISTs. Methods: We searched MEDLINE, EMBASE and the Cochrane Library for relevant articles. A systematic review was performed to calculate pooled hazard ratios (HRs) for disease-free survival (DFS) and overall survival (OS) by fixed-effects/random-effects models. Results: Fourteen studies containing 3,151 subjects were finally enrolled in this meta- analysis. Eight studies including 2,560 patients investigated the prognostic effect of PLR, and thirteen studies with 2,751 subjects explored the prognostic effect of NLR. Both elevated PLR (HR: 1.29, 95% CI: 1.10-1.52, P=0.002) and NLR (HR: 1.37, 95% CI: 1.15-1.63, P=0.0005) were significantly associated with decreased DFS. The pooled HR for PLR was not significantly different from that for NLR. High PLR and NLR correlated with increased tumour sizes, more advanced tumour stages and mitotic index (>5/50 HPF). In addition, elevated PLR was related to adjuvant tyrosine kinase inhibitor (TKI) therapy. Conclusions: Elevated preoperative PLR and NLR are associated with poor outcomes in patients with GISTs.