Expression of chemokine receptor CCR7 is a negative prognostic factor for patients with gastric cancer: a meta-analysis

Abstract

Background: The prognostic significance of CC chemokine receptor type 7 (CCR7) for survival of patients with gastric cancer remains controversial. To investigate the impacts of CCR7 on clinicopathological findings and survival outcome in gastric cancer, we performed a meta-analysis. Methods: A comprehensive search in PubMed, Embase, the Cochrane Library, and the CNKI database (1966 to November 2015) was undertaken for relevant studies. The relative risk and hazard ratios with their 95 % confidence intervals were used as measures to investigate the correlation between CCR7 expression and clinicopathological findings and overall survival rate. Sensitivity analysis was conducted to assess the stability of outcomes. Results: Fifteen eligible studies comprising 1697 participants were included in our analysis. The pooled relative risks indicated CCR7 expression was significantly associated with deeper tumor invasion [0.61, 95 % confidence interval (CI) 0.45–0.84, p = 0.003], advanced stage (0.47, 95 % CI 0.32–0.69, p < 0.001), vascular invasion (2.12, 95 % CI 1.20–3.73, p = 0.009), lymph node metastasis (2.00, 95 % CI 1.48–2.70, p < 0.001), and lymphatic invasion (1.98, 95 % CI 1.43–2.72, p < 0.001) but not with age, tumor size, and histological type. The pooling of hazard ratios showed a significant relationship between positive CCR7 expression and worse 5-year overall survival rate (0.46, 95 % CI 0.31–0.70, p < 0.001). Conclusions: Our meta-analysis indicated high CCR7 expression is likely to be a negative clinicopathological prognostic factor for patients with gastric cancer and to predict a worse long-term survival outcome.