The prognostic value of C-X-C chemokine receptor 4 in non-small cell lung cancer: A meta-analysis

This study aims to better define the roles of CXCR4 in mediating and/or modulating and prognosis of CXCR4 in NSCLC. 10 publications were included by searching PubMed, Scopus, EMBASE, and CENTRAL databases. Primary outcomes were overall survival (OS) and disease-free survival (DFS). Effect sizes were summarized using Hazard ratios (HRs) and their 95% confidence intervals (CIs). The results revealed CXCR4 expression did not significantly correlate with prognosis according to OS and DFS in NSCLC patients. However, high CXCR4 expression was significantly associated with poor prognosis of OS in ≤ 70% stage I NSCLC (HR, 1.79; 95% CI, 1.36-2.37; P=0.000), while that was reverse in > 70% stage I (HR, 0.49; 95% CI, 0.32-0.75; P=0.001). Additionally, high CXCR4 expression was significantly correlated with poor OS in Asian subgroup (HR, 2.11; 95% CI, 1.57-2.85; P=0.000), and was significantly associated with poor OS in less male group (≤ 70% male; HR, 1.88; 95% CI, 1.28-2.77; P=0.001), but no significant association between high CXCR4 expression and OS was found in follow-up period subgroups. High CXCR4 expression might potentially allow for prediction of OS in ≤ 70% stage I NSCLC, since it was associated with increased survival for > 70% stage I NSCLC. Besides, Asian was a much worse factor for prognosis of advanced NSCLC patients, whose CXCR4 was overexpressed, and gender might be an important factor for the correlation between high CXCR4 expression and prognosis of NSCLC patients. However, larger scale trials with strict design, varied subpopulations, and long-term outcomes are needed.