Role of MALAT1 as a Prognostic Factor for Survival in Various Cancers: A Systematic Review of the Literature with Meta-Analysis

Objectives. The expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a highly abundant and ubiquitously expressed long noncoding RNA (lncRNA), influences clinical parameters and may have prognostic value in cancer. This meta-analysis evaluated the prognostic role of MALAT1 in various cancers. Materials and Methods. Systematic literature searches of PubMed and EMBASE databases were conducted for eligible studies of the prognostic role of MALAT1 in cancer. Overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) were analyzed. Summary hazard ratios (HRs) and 95% confidence intervals (95% CIs) were assessed to evaluate the influence of MALAT1 expression on patient prognosis. Results. Nine studies with a total of 932 patients were included in the analysis. Elevated MALAT1 expression was significantly correlated with poor OS (HR 2.02; 95% CI: 1.62-2.52; P < 0.001; I-2 = 0%). Subgroup analysis indicated that tumor type, histology type, ethnicity, and measurement technique did not affect the prognostic value of MALAT1 for OS. The HR of elevated MALAT1 for DFS was 2.78 (95% CI: 1.87-4.15; P < 0.001; I-2 = 0%). Conclusions. Elevated MALAT1 expression is correlated with poor OS in various types of cancer, suggesting that this gene is a prognostic factor for different types of cancer.