Correlation of CXCR4 expression with clinicopathological characteristics and prognosis of patients with non-small cell lung cancer: a Meta-analysis

Objective To systematically evaluate the relationship between CXCR4 and the clinicopathological characteristics and prognosis of patients with non-small cell lung cancer (NSCLC). Methods The PubMed, EMbase, Cochrane Library, CNKI, Wanfang and China Biology Medicine databases were searched by the computer to collect the publicly published cohort studies on the correlation between CXCR4 expression and prognosis of NSCLC. The retrieval time was from the establishment of the database to May 31, 2018. Literature screening, data extraction and risk of bias were performed independently by two reviewers, and Meta-analysis was performed by using Stata 12.0 software. Results Finally, 20 studies were included, with a total of 2 124 NSCLC patients. The positive expression rate of CXCR4 in patients with adenocarcinoma was 51.8% (337/650) and it was 50.3% (224/445) in patients with squamous cell carcinoma, the difference was statistically significant (RR=1.22, 95% CI 1.09-1.38, P=0.001). The positive expression rate of CXCR4 in patients with stageⅠ-Ⅱ was 41.1% (317/772), and the rate was 57.0% (348/610) in patients with stage Ⅲ-Ⅳ, the difference was statistically significant (RR=0.62, 95% CI 0.55-0.69, P < 0.01). The positive expression rate of CXCR4 in patients with distant metastasis was 55.3% (268/485), and the positive rate of CXCR4 in those without distant metastasis was 39.2% (256/653), the difference was statistically significant (RR=1.78, 95% CI 1.54-2.06, P < 0.01). The expression of CXCR4 was not related to the size and invasion of the primary tumor, the positive expression rates of CXCR4 in T1-T2 and T3-T4 patients were 41.0%(215/524) and 53.8%(84/156) (RR=0.71, 95% CI 0.60-0.84, P=0.053). The overall survival rate of patients with CXCR4-positive was lower than that of patients with CXCR4-negative, and the difference was statistically significant (30.1% vs. 66.9%, RR=0.45, 95% CI 0.30-0.61, P < 0.01). The disease-free survival rate of patients with CXCR4-positive was lower than that of patients with CXCR4-negative (38.0% vs. 20.1%, RR=1.89, 95% CI 1.45-2.47, P=0.002). Conclusions The pathological type, tumor staging and distant metastasis of NSCLC patients are correlated with CXCR4 expression level. The expression level of CXCR4 in tumor tissues has a predictive value for the prognosis of NSCLC patients; and the higher the expression level of CXCR4 is, the lower the overall survival and disease-free survival rates are. Key words: Carcinoma, non-small-cell lung; CXCR4; Prognosis; Meta-analysis