Expression Analysis, Diagnostic and Prognostic Accuracy of microRNAs in Oral Cancer: An Overview With Meta-Analysis

Area of Science:

• Oncology
• Molecular Biology
• Biomarker Research

Background:

• Oral squamous cell carcinoma (OSCC) poses a global health challenge due to late diagnosis and limited prognostic tools.
• MicroRNAs (miRNAs) are investigated as potential biomarkers for early detection and outcome prediction in OSCC.
• Variability in research methodologies has impeded the clinical translation of miRNA biomarkers.

Purpose of the Study:

• To synthesize evidence on the diagnostic accuracy of miRNAs in oral cancer.
• To evaluate the prognostic significance of miRNAs in oral cancer.
• To analyze the differential expression of miRNAs in oral cancer.

Main Methods:

• A meta-analysis of systematic reviews and original studies was performed.
• Prognostic significance was assessed using hazard ratios (HRs) for miRNA expression and survival.
• Diagnostic accuracy was evaluated using area under the curve (AUC) values from 12 studies.
• Differential expression was analyzed using standardized mean differences (SMDs) from 11 entries.

Main Results:

• Upregulated miRNA expression is significantly associated with a >2-fold increased risk of poor survival in oral cancer (HR=2.31).
• miRNA-based tests demonstrate moderate-to-high diagnostic accuracy (AUC=0.787), with high variability in noninvasive samples (serum, saliva).
• Oncogenic miRNAs were upregulated (SMD=+0.29) and tumor suppressors downregulated (SMD=-0.52), masked in overall analysis.

Conclusions:

• Dysregulated miRNA expression is linked to poorer prognosis and moderate-to-high diagnostic accuracy in oral cancer.
• Consistent expression patterns highlight miRNAs' roles as oncogenic or tumor-suppressive.
• Standardization of methods and prospective validation are crucial for clinical integration of miRNA biomarkers.