Prognostic Value of Differentially Expressed LncRNAs in Triple-Negative Breast Cancer: A Systematic Review and Meta-Analysis

Breast cancer is the most common cancer in women worldwide and can be classified into multiple subtypes, including triple-negative breast cancer (TNBC). TNBC is more aggressive than other types of breast cancer and has a poor prognosis. However, excluding chemotherapy, the treatment of TNBC does not involve targeted therapy. The dysregulated expression of lncRNAs plays a vital role in the development of numerous cancers. Thus, the aim of this meta-analysis is to determine the functional roles of lncRNAs in TNBC. We performed a systematic search for articles related to TNBC using multiple online databases, including PubMed, EMBASE, Web of Science, and Science-Direct. We collated pooled hazard ratios with 95% confidence interval to estimate the prognostic value of lncRNAs. We assessed the quality of studies using the Newcastle-Ottawa scale. Data were collected from cohort studies that compared overall survival, disease-free survival, and relapse-free survival between patients with high and patients with low expression of lncRNAs. Using 2,192 samples from 21 studies, we observed a correlation between poor prognosis and the upregulation of 14 lncRNAs (LINC00173, HUMT, HOTAIR, LUCAT1, HIF1A-AS2, ZEB2-AS1, NAMPT-AS, DANCR, LINC01638, ZNF469-3, AFAP1-AS1, ANRIL, MALAT1, and HULC) and downregulation of four lncRNAs (MIR503HG, NEF, TC0NS_12_00002973, and GAS5). The pooled hazard ratios for the correlation between differentially expressed lncRNAs and overall, disease-free, and relapse-free survival were 2.38 (2.03-2.78), 2.19 (1.51-3.16), and 3.19 (0.81-12.53), respectively. This meta-analysis shows that the expression of candidate lncRNAs may reliably predict the prognosis of patients with TNBC.