Abstract
Introduction
Cancer is one of the major public health problems worldwide. 1 Many patients with cancer are diagnosed at a later stage, significantly reducing the survival rate of patients. 2 Since early diagnosis and accurate prognosis analysis are the fundamental premise to improve the survival rate of patients, it is urgent to find more effective prognostic biomarkers to predict prognosis and provide better and more suitable therapy for patients with cancer.
Long noncoding RNAs (lncRNAs) are a class of noncoding transcripts longer than 200 nucleotides.
3
Accumulating evidences indicate that lncRNAs play tremendous roles in epigenetics and biological processes, including cell proliferation, differentiation, apoptosis, and migration.
4
-6
Long noncoding RNAs are abnormally expressed in the various cancers, functioning as oncogenes or tumor suppressors.
7
Moreover, recent studies show that lncRNA plays a vital role in prognosis and metastasis of patients with cancer.
8,9
Zhou
BRAF-activated noncoding RNA (BANCR), located at chromosome 9, was originally found in melanoma cells.
13
Li
Materials and Methods
Search Strategy
PubMed, Web of Science, Medline, CNKI, and the Cochrane Library were systematically searched. The search strategy used both Medical Subject Headings (MeSH) terms and free-text words to increase sensitivity. The following search terms were used: “BRAF-activated non-protein coding RNA,” “BANCR,” and “LINC00586.” Additionally, we screened the references of retrieved relevant articles to identify potentially eligible literatures.
Inclusion and Exclusion Criteria
The inclusion criteria were as follows: (1) the BANCR expression was evaluated in human cancer tissues, (2) the relationship between the expression of BANCR and clinicopathologic features or prognosis was described; and (3) the articles must provide sufficient data to calculate the hazard ratios (HR) and 95% confidence interval (CI) for prognosis or odds ratios (OR) and 95% CI for clinicopathologic features. Exclusion criteria were as follows: (1) studies of letters, editorials, expert opinions, case reports, and reviews; (2) duplicate publications.
Data Extraction
Two investigators extracted the data independently by the same standard and the following information were extracted: first author, publication year, country of origin, cancer type, total number of patients, correlation between BANCR expression and clinicopathologic characteristics, and the HR and the corresponding 95% CI or survival curve for overall survival (OS).
Quality Assessment
The quality assessment is an important component of a thorough meta-analysis. Two investigators independently performed this quality assessment. The NOS criteria included 3 aspects of studies: (1) selection: 0 to 4; (2) comparability: 0 to 2; and (3) outcome: 0 to 3. 23 The total Newcastle-Ottawa Scale (NOS) scores were ranged from 0 to 9.
Statistical Analysis
All analyses were performed using the STATA software version 11.0 and Cochrane Collaboration Review Manager Version 5.2. The HRs and 95% CI were used to evaluate the association between BANCR expression and OS. The ORs and 95% CI were used to evaluate the relationship between BANCR expression and clinicopathologic features. We extracted the HRs and 95% CI according to the following methods: (1) the HRs and 95% CI were obtained directly from the articles; (2) the HRs and 95% CI were calculated by the total number of events or survival rate and the
To investigate the heterogeneity among studies,
Results
Study Selection and Characteristics
As shown in the flow diagram (Figure 1), the electronic search acquired 158 records from PubMed, Web of Science, Medline, CNKI, and the Cochrane Library. A total of 125 irrelevant studies or duplicates were excluded by screening titles and abstracts. Then, after assessing the full text, we ultimately included 14 studies in the final analysis. 14,16,18,19,21,26 -34 Among the included studies, 9 studies were enrolled to analyze the prognostic role of BANCR in human solid tumors, and 11 studies were employed to evaluate the association of high BANCR expression with clinicopathologic features.

The flow diagram of this meta-analysis.
The main characteristics of studies were included in Table 1. The 14 studies included a total of 1383 patients, with sample sizes ranging from 54 to 184 patients. Ten different types of cancer were included in this analysis. In all of included studies, the patients were divided into high-expression group and low-expression group according to the expression of BANCR. The NOS scores were from 6 to 8. All studies used qRT-PCR to measure the expression of BANCR. All diagnoses were based on pathology.
Characteristics of Studies in This Meta-Analysis.
Abbreviations: BC, bladder cancer; CRC, colorectal cancer; ESCC, esophageal squamous cell carcinoma; GC, gastric cancer; HCC, hepatocellular carcinoma; HR, hazard ratio; NSCLC, non-small cell lung cancer; OS, overall survival; PTC, papillary thyroid carcinoma; qRT-PCR, quantitative real-time polymerase chain reaction; Rb, retinoblastoma.
Associations Between BANCR Expression and Prognosis
Nine studies investigated the association between BANCR expression and OS in a total of 1013 patients. The random-effects model was used as the significant heterogeneity (

Forest plot for the association between BANCR expression and overall survival in solid tumors. BANCR indicates BRAF-activated nonprotein coding RNA.
Aiming to investigate the source of heterogeneity, subgroup analysis and meta-regression were performed by cancer type, number of patients, survival analysis method, and NOS scores (Table 2).The significant relationship between high BANCR expression and poor prognosis were also observed in digestive system cancers (HR = 1.63, 95% CI: 1.30-2.04,
Subgroup Analysis and Meta-Regression of the Studies Reporting the Association of High BANCR Expression and Overall Survival of Cancer.
Abbreviations: BANCR, BRAF-activated noncoding RNA; CI, confidence interval; HR, hazard ratio.
Associations Between BANCR Expression and Clinicopathologic Features
Eleven studies reported the association between BANCR expression and clinicopathologic features in a total of 1062 patients. According to the heterogeneity, random-effects model or fixed-effects model were used, respectively, to analyze the association between BANCR expression and clinicopathologic features. The results showed that high BANCR expression was significantly associated with advanced tumor stage (OR = 2.57, 95% CI: 1.14-5.79,
Meta-Analysis Results of the Associations of High BANCR Expression With Clinicopathological Parameters.
Abbreviations: BANCR, BRAF-activated nonprotein coding RNA; CI, confidence interval; HR, hazard ratio; TNM, Tumor-Node-Metastases.
Publication Bias and Sensitivity Analysis
The sensitivity analysis was conducted by omitting any single study in turn from the pooled analysis. The results showed that the pooled HRs had no significant change after removing each study (Figure 3). Thus, this sensitivity analysis confirmed the reliability of our results. When we removed Sun

Sensitivity analyses of included studies. A, Prognosis, (B) gender, (C) TNM stage, (D) differentiation grade, (E) lymph node metastasis, and (F) distant metastasis. TNM, Tumor-Node-Metastases.
Publication bias of this meta-analysis was assessed by the Begg test, and the result indicated no significant publication bias (

Funnel plot for the evaluation of potential publication bias. A, Prognosis, (B) gender, (C) TNM stage, (D) differentiation grade, (E) lymph node metastasis, and (F) distant metastasis.
Discussion
Long noncoding RNAs were previously described to be transcriptional noise or garbage. 35 Recently, increasing studies have reported that lncRNAs were involved in the initiation and progression of cancers. 36 BRAF-activated noncoding RNA is mainly induced by BRAFV600E and could regulate melanoma cell migration by regulating expression of CXCL. 13 Subsequently, many studies focused on the role of BANCR in human solid tumors. 37 -39 However, the prognostic role of BANCR in solid tumor still remains controversial. A number of studies reported that high expression of BANCR was associated with poor prognosis of patients with cancer. These studies consistently suggest that BANCR serves as an oncogene, but few studies in suggested BANCR acts as tumor suppressor gene in lung cancer. BRAF-activated noncoding RNA expression was significantly downregulated in lung cancer tissues, and low BANCR expression was associated with worse prognosis in patients with lung cancer. The difference in BANCR between lung cancer and other solid tumors may be attributed to tumor heterogeneity. Moreover, some studies investigating the clinical implications of BANCR are limited by small sample size. The results may be inaccurate due to small sample size. Therefore, we performed this meta-analysis to explore the precise prognostic role and clinical significance of BANCR in human solid tumors.
Most of the included studies come from China. Cancer statistics in China reported that with increasing incidence and mortality, cancer is the leading cause of death in China and a major public health problem. 40 Besides, the 5-year survival rate of patients with cancer in China is still frustrating. The prognosis of patients with cancer in China have been an important health problem. This current status could explain why most of studies were found in China.
In the present study, we combined 9 studies in a total of 1013 patients to investigate the prognosis role of BANCR. The result showed that high BANCR expression was associated with poor prognosis for human solid tumors (HR = 1.66, 95% CI: 1.19-2.32,
All included studies were nonrandomized studies. The quality assessment by the NOS criteria is an important component of a thorough meta-analysis of nonrandomized studies. We found that the quality scores of included studies were all more than 6 scores. The quality assessment suggested indicate that the results of included studies were reliable.
The heterogeneity of included studies in this meta-analysis was significant, but the subgroup analysis and meta-regression was failed to determine the source of heterogeneity. We further performed sensitivity analysis by omitting any single study in turn from the pooled analysis. When we removed Sun
Nevertheless, the present study still has some limitations. First, the pooled analysis included different types of cancers which may increase heterogeneity. Second, the HRs and 95% CI were estimated by Kaplan-Meier survival curves in 2 studies. This method may generate some potential deviations. Third, different methods were employed to divide high- and low-expression group. Fourth, lacking of adequate studies in different cancer types is one of the limitations in this meta-analysis.
In conclusion, this meta-analysis indicated that high BANCR expression was associated with poor prognosis for human solid tumors. Moreover, high BANCR expression has an association with advanced tumor stage, lymph node metastasis, and distant metastasis. Thus, BANCR may be a potential novel biomarker to predict prognosis and progression of human solid tumors.
