Work

Prognostic value of microRNA expression in pancreatic ductal adenocarcinoma: a systematic review and meta-analysis

Year: 2026

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: Background Pancreatic ductal adenocarcinoma (PDAC) ranks among the deadliest malignancies, with limited survival benefits despite recent therapeutic advances. Few prognostic biomarkers are available for PDAC monitoring in clinical practice. We conducted a meta-analysis to evaluate and synthesise evidence on the prognostic significance of miRNA expression in PDAC. Methods The protocol was registered with PROSPERO (CRD42023463542). We conducted a systematic search in PubMed, CENTRAL, and Embase on January 27, 2026, to identify studies assessing miRNA expression levels in patients with PDAC with reported overall survival (OS) or progression-free survival (PFS) outcomes. Hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled using a random-effects model. Prediction intervals (PI) were reported if feasible. Separate analyses were performed by miRNA functional categories: oncogenic, tumour suppressor, chemoresistance-related, metastasis-related, and dual-role miRNAs. Findings A total of 142 studies, including 13,824 patients, were included. High expression of oncogenic miRNAs was associated with worse univariate OS (HR 1.70, 95% CI 1.38–2.10; 95% PI 0.63–4.57) and PFS (HR 2.25, 95% CI 1.63–3.10; 95% PI 1.11–4.55). High expression of chemoresistance-related miRNAs was associated with worse multivariate OS (HR 2.11, 95% CI 1.68–2.66; 95% PI 0.96–4.68) and PFS (HR 2.51, 95% CI 1.89–3.33; 95% PI 1.58–3.97). Between-study heterogeneity varied substantially across pooled analyses (I 2 range 0–94%). miRNA-21 was the most frequently studied individual biomarker and showed a consistent association with worse multivariate OS (HR 2.24, 95% CI 1.95–2.57; 95% PI 1.92–2.61). Interpretation Elevated expression of oncogenic and chemoresistance-related miRNAs is associated with worse survival outcomes in PDAC. However, substantial heterogeneity and wide prediction intervals observed in several pooled analyses indicate variability in effect sizes across studies. Among the investigated biomarkers, miRNA-21 has shown the most consistent prognostic association and may represent the strongest candidate for future clinical implementation. Further validation and standardisation are required before miRNA profiling can be integrated into routine clinical practice. Funding None to declare.

Source: EBioMedicine

DOI: 10.1016/j.ebiom.2026.106528