Prognostic value of long non-coding RNA CCAT1 expression in patients with cancer: A meta-analysis

<div><p>Background</p><p>LncRNA CCAT1 is significantly overexpressed in various types of cancers, suggesting that it might be associated with prognosis and clinicopathological features in patients with cancer.</p><p>Methods</p><p>A comprehensive search was performed in Pubmed, Web of Science, OVID and CNKI databases. We also retrieved articles from other sources, such as retrieving from the reference lists of relevant articles. Eligible studies were included based on defined exclusion and inclusion criteria to perform a meta-analysis. STATA 14.0 was used to estimate pooled hazard ratios (HRs) with 95% confidence interval (95% CI), the heterogeneity among studies and publication bias to judge the prognostic value.</p><p>Results</p><p>A total of 1587 patients from 11 eligible studies were included in the meta-analysis. The results showed that high expression level of CCAT1 was significantly associated with shorter overall survival in cancer patients (HR 2.335, 95% CI:1.551–3.517); in the subgroup analysis, region (China or UK), sample size (more or less than 100), type of cancer (digestive or non-digestive disease) and paper quality (score more or less than 7) did not alter the association between CCAT1 expression and cancer prognosis but preoperative treatment did. And CCAT1 expression was an independent prognostic marker for overall survival in patients with cancer (pooled HR 2.195, 95%CI:1.316–3.664) using Cox multivariate analyses. The clinicopathological parameters analysis further showed that increased expression level of CCAT1 was correlated with tumor size, lymph node metastasis, TNM stage, distant metastasis, microvascular invasion and capsular formation in relevant cancers.</p><p>Conclusions</p><p>The meta-analysis results from present study suggested that increased expression level of CCAT1 was associated with poor prognosis and can serve as an independent biomarker. And the expression level of CCAT1 was associated with clinicopathological features in relevant cancers.</p></div

Meta-analysis of the independent role of CCAT1 in OS and recurrence of different types of cancer after excluding the outlier study.

<p>Meta-analysis of the independent role of CCAT1 in OS and recurrence of different types of cancer after excluding the outlier study.</p

Results of meta-analysis of increased CCAT1 expression and clinicopathological features in various cancers.

<p>Results of meta-analysis of increased CCAT1 expression and clinicopathological features in various cancers.</p

Meta-analysis of the pooled HRs of OS of different types of cancer with increased CCAT1 expression.

<p>(A) Subgroup analysis of HRs of OS by factor of sample size. (B) Subgroup analysis of HRs of OS by factor of type of cancer. (C) Subgroup analysis of HRs of OS by factor of preoperative treatment. (D) Subgroup analysis of HRs of OS by factor of paper quality.</p

Results of subgroup analysis of pooled hazard ratios of overall survival of different types of cancer with increased CCAT1 expression.

<p>Results of subgroup analysis of pooled hazard ratios of overall survival of different types of cancer with increased CCAT1 expression.</p

Results of subgroup analysis of the independent role of CCAT1 in overall survival/recurrence of different types of cancer.

<p>Results of subgroup analysis of the independent role of CCAT1 in overall survival/recurrence of different types of cancer.</p

Meta-analysis of pooled HRs of OS of cancer with increased CCAT1 expression after excluding the outlier study.

<p>Meta-analysis of pooled HRs of OS of cancer with increased CCAT1 expression after excluding the outlier study.</p

Characteristics of studies included in the meta-analysis.

<p>Characteristics of studies included in the meta-analysis.</p

Meta-analysis of the independent role of CCAT1 in OS and recurrence of different types of cancer.

<p>Meta-analysis of the independent role of CCAT1 in OS and recurrence of different types of cancer.</p

Sensitivity analysis (influence analysis) of the overall pooled study for OS.

<p>The study from Zhang et al., 2016 impacted the overall pooled results significantly. The 95% confidence interval of pooled HR and heterogeneity across studies changed notably after excluding that study.</p