Breast cancer imaging with radiolabeled antibodies
1Garden State Cancer Center, Belleville, NJ 07109, USA.
Abstract:
Over the past 2 decades, numerous anticancer antibodies against different molecular targets and labeled with different gamma-emitting radionuclides have been studied in human tumor xenografts and in clinical trials. In breast cancer, these molecular targets have included principally tumor-associated antigens, such as carcinoembryonic antigen (CEA) and the polymorphic epithelial mucin antigen, MUC1, and more recently the growth factor receptors, EGF-R and HER-2/neu. No antibody-based agent has yet been approved for clinical use in the diagnosis of mammary carcinoma, because few trials have addressed the issue of clinical use of these imaging agents in the management of breast cancer patients. Recently, the CEA antibody Fab' fragment approved for colorectal cancer detection, Arcitumomab (CEA-Scan, [Immunomedics, Morris Plains, NJ]), has been found to image both palpable and nonpalpable breast lesions that were suspicious on screening mammograms. Results to date indicate that Arcitumomab can complement mammography by providing a high specificity and positive predictive value, thus indicating when a patient with an abnormal mammogram may proceed directly to definitive surgery without an intermediate diagnostic biopsy. Breast cancer immunoscintigraphy holds promise for advancing toward immunoPET, which should combine the specificity of antibodies with the high sensitivity and resolution of PET. It is also the foundation of breast cancer radioimmunotherapy with humanized antibodies against CEA and MUC1, as well as other immunotherapy strategies.
Insights
Antibody imaging agents show promise for breast cancer diagnosis. Arcitumomab, a CEA antibody fragment, complements mammography, potentially guiding treatment decisions and reducing unnecessary biopsies.
Area of Science:
- Oncology
- Immunology
- Radiochemistry
Background:
- Anticancer antibodies targeting tumor antigens have been explored for two decades.
- Key targets include carcinoembryonic antigen (CEA), MUC1, EGF-R, and HER-2/neu.
- Few antibody-based agents are approved for breast cancer diagnosis, limiting clinical application.
Purpose of the Study:
- To evaluate the clinical utility of antibody-based imaging agents in breast cancer management.
- To assess the role of Arcitumomab in diagnosing suspicious mammographic lesions.
- To explore the potential of immunoscintigraphy for future breast cancer diagnostics and therapeutics.
Main Methods:
- Review of studies involving radiolabeled antibodies against tumor-associated antigens in breast cancer models and clinical trials.
- Evaluation of Arcitumomab (CEA antibody Fab' fragment) for imaging breast lesions suspicious on mammography.
- Analysis of specificity and positive predictive value of Arcitumomab in comparison to mammography.
Main Results:
- Arcitumomab successfully images palpable and nonpalpable breast lesions.
- This CEA antibody fragment demonstrates high specificity and positive predictive value, complementing mammography.
- Results suggest Arcitumomab can help determine the need for definitive surgery, potentially bypassing diagnostic biopsy.
Conclusions:
- Antibody-based imaging agents, like Arcitumomab, hold significant promise for breast cancer diagnosis.
- Immunoscintigraphy may enhance diagnostic accuracy and streamline patient management pathways.
- This technology forms the basis for advancing immunoPET and radioimmunotherapy for breast cancer.
