Prognostic value and clinicopathologic significance of nm23 in various cancers: A systematic review and meta-analysis

Objective: Extensive studies have been carried out to investigate the association between nm23 expression and the prognosis and clinicopathologic significance of various tumors. Methods and materials: Eligible studies were searched from Embase, China National Knowledge Infrastructure (CNKI), PubMed and Web of Science up to May 2017. In this study, we calculated the pooled hazard ratios (HRs) with 95% confidence intervals (95% CIs) to determine the association between nm23 expression and the prognosis of various tumors. Results: A total of 49 studies were finally included in the meta-analysis. The pooled HRs were 2.00 (95% CIs: 1.44-2.78) for overall survival (OS), 1.23 (95% CIs: 1.04-1.46) for disease-specific survival or progression-free survival (DFS/PFS), and 2.21 (95% CIs: 1.38-3.57) for survival of recurrence-free survival or metastasis-free survival (RFS/MFS). Moreover, the results indicated that low nm23 expression was significantly correlated with the lymph node metastasis (P = 0.002). For the subgroup analysis, the expression of nm23 in patients at N0 stage was obviously higher than the patients with breast carcinoma at N1-N3 stage [Odds ratio (OR)= 2.07, 95% CI (1.31, 3.26), P = 0.002]. Moreover, the expression of nm23 in the patients at N0 stage was remarkably higher than those at N1-N3 stages in the Chinese patients with breast carcinoma and those with nasopharyngeal carcinoma (P < 0.05). Whereas, no statistical difference was noticed in the expression of nm23 in patients of various age, gender, T stage, histological degree, TNM stage, respectively (P > 0.05). Conclusion: Our study suggests that down-regulation of nm23 is related to poor prognosis in many cancers. The expression of nm23 in cancer tissues may serve as an important factor for evaluating the presence of lymph node metastasis.