The role of circulating MiR-34a-5p and MiR-let7a-5p as a diagnostic tumor markers in breast cancer a cross-sectional analysis.

BACKGROUND

Breast cancer (BC) remains a leading cause of malignancy-related deaths in women. underscoring the need for low-cost, fast, sensitive and non-invasive biomarkers. MicroRNAs as a critical regulators of gene expression, with distinct expression profiles linked to tumor genesis. Particularly miR-let7a-5p and miR-34a-5p are circulating molecules with key roles in tumor suppression and proliferation, offering significant diagnostic potential.

OBJECTIVES

This exploratory study investigated the expression levels of circulating miRNAs in breast cancer patients and healthy groups and assessed their potential utility as non-invasive diagnostic biomarkers for breast cancer.

METHODS

200 serum samples were used in this analysis, the amount of each miR expression was measured using RT-qPCR and the fold changes were determined by 2^-ΔΔCt. P-values were determined by the t-test. ROC analysis demonstrated significant diagnostic accuracy to identify BC patients.

RESULTS

Our findings indicate that circulating miR-34a-5p and miR-let-7a-5p are significant non-invasive breast cancer biomarkers, both being notably down-regulated in BC patients compared to healthy controls. With lower expression (fold change 0.503 vs. 0.810), superior diagnostic accuracy (AUC 0.8232) and higher (sensitivity 84%), miR-34a-5p outperformed let-7a-5p. No statistically significant association was identified between the studied miRNAs and age, BMI, or ER expression; however, miR-34a-5p demonstrated a weak negative correlation with PR.

CONCLUSION

Both circulating miR-34a-5p and let-7a-5p are significantly down-regulated in BC patients. MiR-34a-5p showed better accuracy on diagnostic performance, indicating its possible value as a promising non-invasive biomarker for the detection of breast cancer. This study explores the potential of these miRs in developing cost-effective strategies for breast cancer detection and risk assessment, monitoring and classification.