Radiopharmaceuticals for Breast Cancer and Neuroendocrine Tumors: Two Examples of How Tissue Characterization May Influence the Choice of Therapy

Abstract

Molecular medicine has gained clinical relevance for the detection and staging of oncological diseases, to guide therapy decision making and for therapy follow-up due to the availability of new highly sensitive hybrid imaging camera systems and the development of new tailored radiopharmaceuticals that target specific molecules. The knowledge of the expression of different receptors on the primary tumor and on metastases is important for both therapeutic and prognostic purposes and several approaches are available aiming to achieve personalized medicine in different oncological diseases. In this review, we describe the use of specific radiopharmaceuticals to image and predict therapy response in breast cancer and neuroendocrine tumors since they represent a paradigmatic example of the importance of tumoral characterization of hormonal receptors in order to plan a tailored treatment. The most attractive radiopharmaceuticals for breast cancer are 16α-[18F]-fluoro-17β-estradiol for PET assessment of the estrogen expression, radiolabeled monoclonal antibody trastuzumab to image the human epidermal growth factor receptor 2, but also the imaging of androgen receptors with [18F]-fluorodihydrotestosterone.

Breast cancer, screening and diagnostic tools: All you need to know

“…This technique is non-invasive, reproducible and provides valuable information of the tumor stage. In addition, [ 18 F]-FES uptake is correlated with ER overexpression, such correlation can predict the patient's response to hormonal therapy (HT) [186]. [ 18 F]-FES PET as a diagnostic tool can differ from early stage tumors and metastases, this modality is usually used instead of biopsy or when it has undetermined results [186][187][188]).…”

“…In addition, [ 18 F]-FES uptake is correlated with ER overexpression, such correlation can predict the patient's response to hormonal therapy (HT) [186]. [ 18 F]-FES PET as a diagnostic tool can differ from early stage tumors and metastases, this modality is usually used instead of biopsy or when it has undetermined results [186][187][188]). A study carried by van Kruchten et al in 33 patients who underwent [ 18 F]-FES PET reported [ 18 F]-FES positive lesions in 22 patients, higher bone metastases lesions were detected by [ 18 F]-FES PET compared with other conventional imaging methods (341 vs 246 bone metastases lesions respectively), additionally, an 88% improvement in diagnosis and 48% of the patients reported a change in therapy [186,188].…”

“…A study carried by van Kruchten et al in 33 patients who underwent [ 18 F]-FES PET reported [ 18 F]-FES positive lesions in 22 patients, higher bone metastases lesions were detected by [ 18 F]-FES PET compared with other conventional imaging methods (341 vs 246 bone metastases lesions respectively), additionally, an 88% improvement in diagnosis and 48% of the patients reported a change in therapy [186,188]. Several studies performed with [ 18 F]-FES PET have shown a 84% and 98% sensitivity and specificity respectively [186].…”

Theranostic Advances in Breast Cancer in Nuclear Medicine

“…Considering that this therapeutic protocol imposes patient high costs and despite that may be ineffective, assessment pre-treatment physiologic manner of the trastuzumab would be noteworthy. Also, this is demonstrated that some negative HER2 patients can benefit from therapeutic trastuzumab as an anti-HER2 agent [ 48 ]. In this regard biodistribution and accumulation of trastuzumab radiolabelled with Indium-111, [ 111 In]In-trastuzumab, as an imaging agent for single photon computed emission tomography (SPECT) has been evaluated [ 48 ].…”

“…Also, this is demonstrated that some negative HER2 patients can benefit from therapeutic trastuzumab as an anti-HER2 agent [ 48 ]. In this regard biodistribution and accumulation of trastuzumab radiolabelled with Indium-111, [ 111 In]In-trastuzumab, as an imaging agent for single photon computed emission tomography (SPECT) has been evaluated [ 48 ]. In preclinical studies, significant and specific accumulation of [ 111 In]In-trastuzumab was proved in human HER2 tumour-bearing mice [ 49 ].…”