Crunching the numbers. Responsibly.
BACKGROUND: Circular RNA ubiquitin-associated protein 2 (circUBAP2) is highly expressed in various human cancers and has been identified as a key contributor to cancer development and progression. We performed this study to explore the clinicopathological and prognostic significance of circUBAP2 in multiple cancers. METHODS: This meta-analysis was conducted according to PRISMA 2020 guidelines. PubMed, Web of Science, CNKI, Wanfang, ClinicalTrials.gov and BioXiv were systematically searched from inception to March 1, 2025 according to the PICO framework. Study quality was appraised using the Newcastle-Ottawa Scale and eventually a total of 12 studies with 905 participants were included. Pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were synthesized using fixed- or random-effects models based on heterogeneity (I² statistic) to evaluate the association of circUBAP2 with age, sex, tumor size, stage, differentiation and metastasis. The stability of the results from meta-analysis was estimated via sensitivity analysis. Begg’s funnel plots and Egger’s test were used to appraise the potential publication bias. Subgroup analysis for overall survival (OS) based on follow-up duration, tumor type, case number and survival endpoints were also performed. RESULTS: High expression of circUBAP2 was significantly related to larger tumor size (OR = 3.07, 95% CI: 1.53–6.17, P < 0.05), advanced stage (OR = 2.43, 95% CI: 1.70–3.48, P < 0.05), poor differentiation (OR = 4.47, 95% CI: 2.67–7.48, P < 0.05) and metastasis (OR = 5.77, 95% CI: 3.21–10.40, P < 0.05), but not associated with age or sex. Additionally, circUBAP2 was related to cancer survival (HR = 2.43, 95% CI: 1.96–3.03, P < 0.05), regardless of follow-up duration, tumor type, case number, and survival endpoints. Begg’s funnel plot and Egger’s test showed no publication bias. CONCLUSIONS: High expression of circUBAP2 may predict larger tumor size, poor differentiation, distant metastasis and poor outcome of cancer, highlighting the carcinogenetic role of circUBAP2 in human cancer.
Strengths
The Introduction identifies the absence of prior meta-analysis on circUBAP2 in human cancer, and the Results aggregate 12 studies covering clinicopathological features and survival outcomes. This gives the paper a clear role as an initial evidence map for a narrow biomarker question.
↳ Introduction; Results, Characteristics of Included Studies; Table 1
The Methods state OSF registration, PRISMA checklist use, searches across PubMed, Web of Science, CNKI, Wanfang, ClinicalTrials.gov, and BioXiv, plus dual screening and extraction with adjudication. These features support a competent baseline evidence-synthesis workflow.
↳ Methods, Search Strategies; Methods, Selection Process; Methods, Data Extraction
The Discussion identifies a small total evidence base, survival information extracted from curves, and underpowered cancer-specific strata. This helps readers interpret the pooled pan-cancer estimates as preliminary rather than definitive.
↳ Discussion, Limitations
Limitations
The review does not report GRADE or an equivalent certainty-of-evidence assessment despite drawing clinically relevant prognostic conclusions. This limits how clearly readers can distinguish statistical significance from confidence in the evidence base.
↳ Methods; Results; Discussion
The included studies span multiple tumor types with small individual strata, and some outcomes are represented by only one or two studies. The broad pooled associations therefore do not establish reliable tumor-specific clinical utility.
↳ Results, Table 1; Results, Table 3; Discussion, Limitations
The Search Process exclusion counts do not reconcile exactly, Table 3 uses a fixed-effects model for a subgroup with I²=52.5% despite the stated model rule, and the Discussion contains awkward or garbled wording. These issues do not overturn the main results but reduce confidence in reporting discipline.
↳ Results, Search Process; Methods, Statistical Analysis; Table 3; Discussion
The adjudicated quality score reflects a competent but not best-practice systematic review. The strongest elements are the registered PRISMA-framed workflow, dual review processes, and clear presentation of pooled clinicopathological and survival associations in Tables 2–3 and Figures 3–6. The main methodological constraints are the absence of a formal certainty assessment, sparse and heterogeneous retrospective evidence, survival-curve extraction, and limited reproducibility of data or code. The UBAP2/TCGA analysis is transparently described as indirect because TCGA lacks matching circRNA annotations, but it still adds interpretive complexity rather than strengthening the core circUBAP2 synthesis.
Moderate3.1/5.0
The study addresses a real synthesis gap by aggregating the clinicopathological and prognostic literature on circUBAP2 across human cancers. The contribution is modest because it is a narrow single-biomarker meta-analysis based on 12 retrospective studies and 905 participants.
no meta-analysis has been performed
The methods include OSF registration, PRISMA alignment, six searched sources, dual screening/extraction, NOS assessment, sensitivity analysis, and publication-bias checks. The score is limited by absence of GRADE, small-study publication-bias testing, incomplete search/data/code reproducibility, survival-curve extraction, and an effects-model inconsistency in Table 3.
Meta-regression was not feasible due to limited number of studies
The article follows a conventional systematic-review structure and presents the main pooled estimates in tables and figures. Reporting is reduced by duplicated sensitivity-analysis wording, awkward or garbled phrasing, and occasional stronger causal or mechanistic language than the meta-analysis directly supports.
highlighting the carcinogenetic role
The Discussion situates circUBAP2 within conflicting mechanistic and cancer-type-specific literature and explicitly acknowledges small sample size, curve-extracted survival data, and underpowered strata. Contextual strength is moderated by the use of linear UBAP2 TCGA analysis as supporting context for circUBAP2 and by limited formal certainty-of-evidence framing.
CircRNA annotations were unavailable for TCGA cohorts
Watch-outs4 of 4 checks
The paper is broadly internally interpretable and the main pooled estimates are consistently reported, but several reporting issues reduce confidence in exactness. These include inconsistent exclusion arithmetic, an effects-model inconsistency in one survival subgroup, overconfident publication-bias language, and minor citation/editing problems.
The review reports OSF registration, PRISMA alignment, dual screening, and dual extraction, but reproducibility and conduct reporting are incomplete. Data and code availability are not provided, conflict-of-interest reporting is not visible in the supplied text, and protocol-to-report consistency cannot be verified from the article alone.
Flags: 1 declared / 5 total
All 31 cited references resolved to real publications via PubMed, Crossref, or OpenAlex.
No retraction notice found in Retraction Watch.
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Low2.7/5.0
The paper addresses a recognized cancer-biomarker problem and is relevant to translational oncology research. Its traction is limited because it does not define a clinical decision point, threshold, assay workflow, or stakeholder implementation scenario.
may predict larger tumor size
The evidence is an observational synthesis rather than a validation or implementation study. No prospective validation, standardized cutoff, clinical assay, or deployment pathway is provided.
Future multi-center, high-quality studies
The review spans nine cancer types, giving some breadth across oncology contexts. Generalizability is constrained by small cancer-specific strata, variable cutoffs, language restriction, and pan-cancer pooling that may obscure tumor-specific behavior.
inconsistent tumor-size cutoffs
As the first synthesis on circUBAP2, the article provides a useful baseline for updated reviews and future validation work. The trajectory is positive but early because the literature base remains small and the authors themselves call for larger multicenter studies.
Future multi-center, high-quality studies
Nabu’s assessment, alongside the field’s view.
Evaluation Metadata
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