The Prognostic Value Of PLR In Patients With Gastrointestinal Stromal Tumors:A Meta-analysis

Objectives:Meta-analysis was used to investigate the relationship between platelet-lymphocyte ratio(PLR)and recurrence-free survival(RFS),overall survival(OS),disease-free survival(DFS)and clinicopathological features(tumor diameter,mitosis,NIH grade,tumor location)in patients with gastrointestinal stromal tumors(GIST).Methods:The article which explored the relationship between preoperative PLR in peripheral blood and prognosis of GIST was retrieved from China National Knowledge Infrastructure(CNKI),VIP,Wanfang,CBM,PubMed,Cochrane Library,Embase,Foreign Medical Jouranal Service(FMJS)and Ovid journals(OVID)databases until February 2019.In accordance with the strict inclusion and exclusion criteria,articles were deliberately selected.Newcastle-Ottawa Quality Assessment Scale(NOS)was used to evaluate the quality of articles.The article information and experimental data were extracted from the included article to make tables.Revamn 5.3 software was used for statistical analysis of the data extracted from the article.Fixed or random effects models were selected according to the size of heterogeneity.When heterogeneity was high,subgroup analysis was performed according to possible sources.Pooled hazard rate(HR)with 95%confidence interval(95%CI)were calculated using the generic inverse variance to evaluate the association of PLR and prognostic variables.When exploring the relationship between PLR and clinicopathological characteristics,relative risk(RR)with 95%CI were calculated.P<0.05 indicated that there was significant difference.Results:A total of 2455 patients from 10 studies were included in the meta-analysis.Eight studies performed univariate analysis of PLR and RFS,suggesting that high PLR predicted a shorter RFS(HR=2.50,95%CI:1.53-4.09,P=0.0003).Multivariate analysis of PLR and RFS was performed in five studies,which also indicated that PLR was negatively correlated with RFS,high PLR predicted shorter RFS(HR=1.99,95%CI:1.63-2.41,P<0.00001).The relationship between PLR and clinicopathological features showed that high PLR predicted larger tumor diameter(RR=1.46,95%CI:1.3 1-1.63,P<0.00001),higher mitotic figure(RR=1.53,95%CI:1.35-1.73,P<0.00001),and higher NIH grade(RR=1.37,95%CI:1.25-1.50,P<0.00001).However,PLR was not significantly correlated with OS,DFS,tumor location(stomach and non-stomach).Subgroup analysis of PLR was performed in different regions(domestic VS foreign)and truncated values(PLR>200 VS PLR<200).The heterogeneity between domestic and foreign research was large,the heterogeneity was large in domestic(I2=71%,P-0.007)and the heterogeneity was also large in foreign(I2=89%,P<0.0001).However,there was no significant heterogeneity(12=0%,P=0.69)when the cut-off value of PLR was greater than or equal to 200.When the truncation value was less than 200,there was significant heterogeneity(I2=89%,P<0.00001).Conclusions:The increased PLR suggested that RFS might be shortened in patients with GIST;The increased PLR suggested that tumor diameter might be larger,mitotic figure might be more,and NIH grade might be higher.Increased PLR often indicated biological properties of tumors and prognosis of patients might be poorer.