Long Noncoding RNA MALAT-1 Can Predict Metastasis and a Poor Prognosis: a Meta-Analysis

Elevated expression of MALAT-1 was found in various cancers, and correlated with metastasis and prognostic. This meta-analysis collected all relevant articles and explored correlation of MALAT-1 with lymph node metastasis (LNM), distant metastasis (DM), and overall survival (OS). A quantitative meta-analysis was performed through a systematic search in PubMed, Web of Science, Medline, CNKI, CBM, and the Cochrane Library. The odds ratios (OR) of LNM and DM and hazard ratio (HR) of OS were calculated to assess the association strength. Eight studies with a total of 845 patients were included in the meta-analysis. Six different types of cancer were evaluated, with 2 non-small cell lung cancer (NSCLC), 1 colorectal cancer (CRC), 1 gastric cancer (GC), 2 pancreatic cancer (PC), 1 clear cell renal cell carcinoma (ccRCC), and 1 osteosarcoma (OSA). Compared with low MALAT-1 expression, high MALAT-1 expression correlated with more LNM (OR = 2.08, 95 %CI: 1.00-4.32, p = 0.05) by a random-effects model (I (2) = 71 %, p = 0.004). A similar result was seen between MALAT-1 expression and DM, the OR was 3.52 (95 %CI: 1.06-11.71, p = 0.04) adopting a random-effects model (I (2) = 59 %, p = 0.04). Additionally, our analysis showed a poorer OS in patients with high MALAT-1 expression than those with low MALAT-1 expression (HR = 2.12, 95 %CI: 1.60-2.82, p < 0.001) adopting a random-effects model (I (2) = 56 %, p = 0.04). MALAT-1 may serve as a molecular marker for cancer metastasis and prognosis.