Current Landscape of Breast Cancer Imaging and Potential Quantitative Imaging Markers of Response in ER-Positive Breast Cancers Treated with Neoadjuvant Therapy

Abstract

In recent years, neoadjuvant treatment trials have shown that breast cancer subtypes identified on the basis of genomic and/or molecular signatures exhibit different response rates and recurrence outcomes, with the implication that subtype-specific treatment approaches are needed. Estrogen receptor-positive (ER+) breast cancers present a unique set of challenges for determining optimal neoadjuvant treatment approaches. There is increased recognition that not all ER+ breast cancers benefit from chemotherapy, and that there may be a subset of ER+ breast cancers that can be treated effectively using endocrine therapies alone. With this uncertainty, there is a need to improve the assessment and to optimize the treatment of ER+ breast cancers. While pathology-based markers offer a snapshot of tumor response to neoadjuvant therapy, non-invasive imaging of the ER disease in response to treatment would provide broader insights into tumor heterogeneity, ER biology, and the timing of surrogate endpoint measurements. In this review, we provide an overview of the current landscape of breast imaging in neoadjuvant studies and highlight the technological advances in each imaging modality. We then further examine some potential imaging markers for neoadjuvant treatment response in ER+ breast cancers.

Accuracy and Reproducibility of Contrast-Enhanced Mammography in the Assessment of Response to Neoadjuvant Chemotherapy in Breast Cancer Patients with Calcifications in the Tumor Bed

“…The DCIS component, instead, is more easily detected through the analysis of calcification morphology in mammography or low-dose images in CEM. This could be of specific interest in patients with invasive disease and DCIS shown on the pre-treatment biopsy since this population is less likely than that without DCIS to achieve pCR (31% vs. 43%; p = 0.038) [ 4 , 5 ]. Lower response, together with faint enhancement observed in DCIS, makes diagnosing residual disease in women with DCIS component challenging.…”

“…NAC requires imaging tools to accurately predict pathological response and, consequently, to guide surgical planning. The accuracy of imaging in defining response is influenced by several variables, including the heterogeneity of breast cancer subtypes [ 4 , 5 , 6 , 7 ] and the antiangiogenetic effect of drugs [ 8 , 9 ].…”

ZR-75-1 breast cancer models to study the utility of 18F-FES by PET imaging

“…18 F-FES-PET/CT can be used for noninvasive evaluation of the ER status in primary and metastatic lesions, thereby predicting the effect of endocrine therapy at an early stage and contributing to individualized therapy. 18 F-FES-PET/CT detects ER-positive tumor lesions with a high sensitivity (84%) and specificity (98%) (11).…”

Estrogen Receptor Signaling in Cancer

“…These mutations can be detected in circulating tumor DNA which is proving a useful method to monitor changes in metastatic disease [ 6 ]. The theme of monitoring responses is the subject of the review by Ella Jones et al who describe the use of breast imaging to assess neo-adjuvant responses in ER-positive breast cancer [ 7 ]. The use of multimodality technologies, e.g., magnetic resonance imaging (MRI) and positon emission tomography, are increasingly being considered in this context.…”

“…The use of multimodality technologies, e.g., magnetic resonance imaging (MRI) and positon emission tomography, are increasingly being considered in this context. Multiparametric techniques have been developed for breast MRI and include volumetric (functional tumour volume), enhancement (background parenchymal enhancement), and diffusion (apparent diffusion coefficient) markers to assess response to therapy [ 7 ]. These approaches are likely to have an increasing part to play in the detection, diagnosis and response prediction for breast cancer in the future [ 7 ].…”