Poor prognosis of nucleophosmin overexpression in solid tumors: A meta-analysis

Background: Nucleophosmin is a non-ribosomal nucleolar phosphoprotein that is found primarily in the nucleolus region of cell nucleus, plays multiple important roles in tumor processes. Accumulated previous studies have reported a potential value of NPM acted as a biomarker for prognosis in various solid tumors, but the results were more inconsistency. We performed this meta-analysis to precisely evaluate the prognostic significance of NPM in solid tumors. Methods: Clinical data were collected from a comprehensive literature search in PubMed, Web of Science, Embase, and China National Knowledge Infrastructure databases (up to October, 2017). A total of 11 studied with 997 patients were used to assess the association of NPM expression and patients' overall survival (OS). The hazard ratio (HR) or odds ratio (OR) with its 95% confidence intervals (CI) were calculated to estimate the effect. Results: The pooled results indicated that higher expression of NPM was observably correlated with poor OS in solid tumor (HR=1.85, 95% CI: 1.44-2.38, P<0.001). Furthermore, high expression of NPM was associated with some phenotypes of tumor aggressiveness, such as tumor stage (4 studies, III/IV vs. I/II, OR=5.21, 95% CI: 2.72-9.56, P<0.001), differentiation grade (poor vs. well/moderate, OR=1.82, 95% CI: 1.01-3.27, P=0.046). Conclusion: This meta-analysis indicated that NPM may act as a valuable prognosis biomarker and a potential therapeutic target in human solid tumors.