Molecular Subtypes and Imaging Biomarkers in Breast Cancer: A Systemic Literature Review

Abstract

Background: Breast cancer ranks first in cancer incidence worldwide. As the leading cause of cancer death in women, breast cancer has become one of the major threats to human health. Approximately 20% of metastatic breast cancer patients only survive for 5 years. Molecular approaches refer to genetic analysis and specific biomarkers associated with breast cancer development. These include BRCA1 and BRCA2 gene mutations, as well as protein expression such as HER2, estrogen receptor (ER), and progesterone receptor (PR). Molecular testing is used to determine the cancer subtype (such as luminal A, luminal B, HER2+, or triple-negative breast cancer) which is important for determining the right therapy, such as hormone therapy or HER2-targeted therapy. Methods: Systematic Reviews, published between 2015 and 2024 worldwide were selected through searches of PubMed, Scopus, Embase, Web of Science, and the Cochrane Library. Conclusion: Breast cancer consists of heterogeneous subtypes and continues to develop after systemic therapy. Previous studies correlating imaging features and molecular subtypes have reported the presence of calcifications, margin or shape features, and enhancement features on dynamic contrast-enhanced MRI corresponding to each subtype. Recent studies using radiomic parameters, which are invisible to the human eye, have demonstrated high accuracy in differentiating molecular subtypes, predicting response to chemotherapy, and predicting survival outcomes. Imaging biomarkers may help in realizing better precision medicine due to the feasibility of repeated measurements across the entire tumor and the application of deep learning-based algorithms.