Emerging biomarkers in breast fibroadenoma: implications for differential diagnosis, malignant transformation, and precision medicine

Fibroadenoma is the most common benign fibroepithelial lesion of the breast; it occurs most frequently in adolescents and women of reproductive age. While fibroadenoma is considered a non-invasive lesion with a good prognosis, some fibroadenomas may show rapid growth, recurrence, stromal hypercellularity, epithelial proliferative changes and even show radiological overlap with phyllodes tumour and breast carcinoma resulting in significant diagnostic dilemmas. In recent years, molecular pathology and biomarker studies have led to better understanding of the biology of fibroadenomas, and their ability to differentiate between fibroadenomas and malignant breast lesions. This review will provide a comprehensive overview of biomarkers involved in the diagnosis, prognosis, prediction, molecular, genetic, epigenetic, functional, circulating and imaging of breast fibroadenoma and breast cancer. The key biomarkers such as MED12 mutation, Ki-67, p53, Bcl-2, ER/PR, HER2, VEGF, MMPs, γ-H2AX, ctDNA, circulating tumour cells and transcriptomic classifiers are discussed in the context of tumour proliferation, apoptosis, angiogenesis, invasion, genomic instability and malignant transformation risk. The retrieved relevant literature was from 2000 to 2025 from the databases of PubMed, Scopus, Web of Science, and Google Scholar. The review further emphasizes the growing significance of liquid biopsy, radiomics, artificial intelligence, digital pathology, and the integration of multi-omics techniques for enhancing lesion classification, diagnostic accuracy, and personalized risk assessment. Many challenges still exist such as a lack of standardised cut off values for biomarkers, overlap between fibroadenoma and phyllodes tumour, a lack of molecular panels specifically designed for fibroadenoma and a lack of long-term validation studies. Further incorporation of molecular profiling, imaging biomarkers, computational pathology, and precision oncology approaches into the future could greatly enhance the risk stratification and handling of benign and malignant fibroepithelial breast lesions.