Relationship between lincRNA-p21 expression and human cancer prognosis: a meta-analysis

Long intergenic noncoding RNA-p21 (lincRNA-p21) regulates key cell processes and is involved in the initiation and progression of human cancers. This meta-analysis explored the relationship between lincRNA-p21 expression and cancer prognosis. Firstly, we searched four electronic databases (Pubmed, Medline, Web of Science, and CochraneLibrary). Then, patient survival and clinicopathological features were extracted and analyzed as pooled hazard ratios (HRs) or odds ratios (ORs). Q and I-2 tests measured study heterogeneity. After that, we pooled HRs of overall survival (OS) and disease-free survival (DFS) using InHR and standard error, and assessed the association between lincRNA-p21 expression and clinicopathological features of tumors using ORs and 95% CIs. Begg's and Egger's tests assessed potential publication bias. A total of five studies comprised of 450 patients were included. Meta-analysis showed that, in most cancers, higher lincRNA-p21 expression was associated with better OS (P = 0.01) and DFS (P = 0.002). Higher lincRNA-p21 expression was also associated with better differentiation grade (P < 0.0001), but not vascular invasion (P = 0.39) or tumor, node, and metastasis stage (P = 0.95). Therefore, for most cancers, increased lincRNA-p21 expression was associated with better OS, DFS, and tumor differentiation grade, and may be a novel tool for cancer prognosis.