Prognostic and Clinicopathological Significance of Long Non-Coding RNA BLACAT1 in Cancer: An Updated Meta-Analysis and TCGA Data Review.

BACKGROUND

Although increasing evidence has shown that long non-coding RNA BLACAT1 could be aberrantly expressed and used as a prognostic marker in various cancers, the results remain inconclusive. In this study, we sought to summarize the relationship between BLACAT1 (bladder cancer associated transcript 1) and relevant clinical outcomes.

METHODS

Eligible studies were retrieved from the online databases PubMed and Web of Science. A meta-analysis was performed using Stata 12.0 software. The Cancer Genome Atlas (TCGA) dataset was further used to verify the results.

RESULTS

A total of sixteen studies were included to evaluate the association of BLACAT1 with overall survival or clinicopathological features by pooled hazard ratio (HR) or odds ratio (OR) in cancer. In the pooled analyses stratified by clinicopathological features, BLACAT1 expressions were closely correlated with lymph node metastasis (OR = 2.52, 95% CI: 1.86 - 3.40, p = 0.000), histological differentiation (OR = 1.98, 95% CI 1.25 - 3.13, p = 0.004), and tumor stage (OR = 1.89, 1.23 - 2.91, p = 0.004), but not to tumor size (OR = 1.91, 95% CI 0.96 - 3.80, p = 0.064) or distant metastasis (OR = 3.76, 95% CI: 0.90 - 15.71, p = 0.07) in cancer. Our results manifested that elevated BLACAT1 expression was markedly associated with poor overall survival (HR = 1.62, 95% CI: 1.41 - 1.84, p = 0.000) and PFS (HR = 2.10, 95% CI: 1.28 - 2.93, p < 0.001) among twelve types of solid cancers. Subgroup analysis demonstrated a significant association between high BLACAT1 expression and shorter OS in the lung cancer (HR = 2.03, 95% CI: 1.66 - 2.40, p = 0.000), colorectal cancer (HR = 1.47, 95% CI: 1.3 - 1.64, p = 0.000). Using Cox multivariate analyses, BLACAT1 expression was found to be an independent prognostic marker for OS in cancer (HR = 1.83, 95% CI: 1.37 - 2.30). TCGA dataset also confirmed that the upregulated BLACAT1 expression was significantly correlated with poor prognosis in cancer.

CONCLUSIONS

Increased BLACAT1 expression was associated with more advanced clinicopathological features and may serve as poor prognosis in various cancers.