Molecular subtypes of breast cancer-what breast imaging radiologists need to know

Abstract

Objective: Summarize the impact generated by the introduction of the molecular classification of breast cancer in the different specialties involved so as to offer radiologists a global view of the current management of this disease, from diagnosis to treatment. Findings: In the last two decades, molecular information based on genomic analysis has helped to understand the biological diversity of breast cancers and generated profound changes in the clinical oncological practice. With simpler and available immunohistochemical tests, it is possible to approximate the molecular classification, enabling the prediction of clinical behavior of the different subtypes (Luminal, HER2-positive, Triple-negative) and their response to different therapies, facilitating the design of personalized treatments. Although no findings absolutely pathognomonic have been described in mammography, ultrasound or magnetic resonance imaging, the molecular classification concept has already two concrete uses: for predicting Luminal A or Triple-negative phenotype on images and for evaluating the neoadjuvant chemotherapy response by magnetic resonance. A future application is expected in the area of radiogenomics. Conclusions: Radiologists dedicated to breast imaging should be familiar with the concepts of molecular classification, necessary for radio-pathological correlation of breast biopsy results and in order to provide an optimal patient care.