Prediction of MiR-155 as Biomarkers in Breast Cancer: A Systematic Review

Despite significant advances in the detection and treatment of breast cancer (BC), it remains one of the most prevalent malignancies worldwide. MicroRNAs (miRNAs) have emerged as critical regulators in cancer biology, influencing tumor initiation, progression, immune evasion, and therapy resistance. Among them, miR-155 is widely recognized as an oncogenic miRNA that promotes tumor growth, angiogenesis, and invasiveness in BC. As a result, it has been extensively studied as a potential predictive biomarker and therapeutic target. However, its predictive value in BC patients remains to be fully elucidated. This systematic review aims to synthesize current evidence on the predictive significance of miR-155 in BC pathology. A comprehensive search of PubMed and Web of Science identified 640 potentially relevant studies, of which 37 met the inclusion criteria for full analysis. These studies assessed miR-155 expression in tissue, blood, and urine samples and its associations with clinical outcomes and pathological features in BC patients. Our analysis suggests that circulating and urinary miR-155 may offer comparable predictive value to tissue-derived miR-155, with potential applications in early diagnosis, disease monitoring, recurrence detection, treatment response, and metastasis prediction. We also identified challenges that limit the clinical translation of miR-155, emphasizing the need for greater consistency and validation across studies.. Overall, this review highlights the promising role of miR-155 in BC management while emphasizing the need for further validation through well-designed clinical studies. T his work has been registered in PROSPERO with registration number CRD420251001681 and date of registration 14th May 2025 .