This year’s National Comprehensive Cancer Network® (NCCN®) Clinical Guidelines for Breast Cancer Treatment, Breast Cancer Screening and Diagnosis Guidelines, and Patient Guidelines on Invasive Breast Cancer added references to certain imaging modalities. These included 18F-fluoroestradiol-Positron Emission Tomography/ computed tomography (FES-PET/CT) and contrast enhanced mammography (CEM), both of which can be useful in some cases for screening, diagnosis, or monitoring of individuals with invasive lobular carcinoma (ILC).
While the clinical guidelines do not yet include specific treatment recommendations related to ILC, we asked Matt Covington, MD, to answer our questions about these new guidelines and to share his thoughts about why these changes may be helpful for individuals with ILC. Dr. Covington is an assistant professor of breast imaging and nuclear medicine at the University of Utah and Huntsman Cancer Institute.
LBCA: Dr. Covington, who uses the Clinical Guidelines for Breast Cancer Treatment and the Breast Cancer Screening and Diagnosis Guidelines?
Dr. Covington: NCCN guidelines such as these are used to guide diagnostic and treatment decisions by oncologists, surgeons, and other clinicians involved in breast cancer diagnosis. Additionally, these guideline influence availability and insurance coverage for imaging studies, and are therefore very important for new imaging techniques such as FES-PET/CT and contrast enhanced mammography.
LBCA: What evidence is needed for the NCCN to update the guidelines?
Dr. Covington: NCCN guidelines are created through a network of experts at leading cancer centers throughout the United States. These guidelines are based on the most recent and important scientific studies. In essence, these guidelines represent the consensus opinion of leading breast cancer experts based on the most recent scientific studies and are regularly updated.
LBCA: How do clinicians in the field learn about updates to the NCCN guidelines?
Dr. Covington: Clinicians in the field learn about NCCN guideline updates from medical society newsletters, as well as email blasts, online webinars, and, of course, medical conferences and publications in scientific journals. The best clinicians consistently seek out this information, and stay up to date on the most recent guidelines and recommendations so they can provide the best care for patients.
LBCA: Tell us about CEM. What is this imaging modality and how might it be useful for those with ILC?
Dr. Covington: CEM is much like a standard mammogram but uses an IV injection of contrast like a contrast-enhanced CT scan. By giving the contrast through the IV prior to imaging, and through some technical updates to the mammography unit, a CEM study improves cancer detection compared to standard 2D or 3D mammography, especially in dense breasts where standard mammography too often fails. The information provided by CEM is similar to a contrast enhanced breast MRI study—since both use IV contrast—but is simpler than MRI to obtain in that it can be quickly obtained through mammography rather than a more expensive and lengthier MRI.
LBCA: Is CEM available everywhere?
Dr. Covington: CEM is currently not available everywhere. Some leading centers have been using CEM for many years. Others are just starting to use it now. Many additional centers are just starting to think about adopting CEM in their own practice. However, excitement regarding CEM in the breast imaging community is building. I expect CEM will become more widely available in coming years.
LBCA: What questions might an individual ask their referring physician, gynecologist, or oncologist about whether CEM would be a good choice for them?
Dr. Covington: The first question I would ask is whether CEM is available in their health system or community. If it is, I would ask what indications CEM is currently used for in their practice, and whether this is a good fit for the particular symptom or scenario an individual is currently evaluating.
There are many potential indications for CEM. However, CEM is most commonly used for individuals with newly diagnosed breast cancer for extent of disease evaluation, treatment monitoring for those with breast cancer on neoadjuvant therapy, or high-risk screening for individuals who cannot obtain MRI due to contraindications.
However, a potential use I am personally most interested in is CEM for dense breast tissue screening. In my opinion, improved breast cancer screening for those with dense breasts is one of the most important currently unmet needs in all of breast imaging. I think CEM could make a big impact through revealing breast cancers in dense breasts that standard mammography will not detect. There are currently several research studies that are started, or will soon be started, studying CEM for breast cancer screening in individuals with dense breasts. I eagerly await the results of these trials. I hope to see CEM available for dense breast tissue screening in the near future.
CEM could specifically benefit individuals with ILC, in that it may help detect lobular cancers earlier, particularly for those invasive lobular cancers that escape detection on standard mammograms. For individuals with a known diagnosis of ILC who cannot undergo MRI for local staging or response to therapy evaluation, CEM provides an alternative method to provide much of the same information available on MRI.
LBCA: If CEM is not available at one’s local health care facility, how would someone go about finding where it is offered?
Dr. Covington: I am not aware of any website or database that lists centers for which CEM is currently available. One strategy is to go to pubmed.gov, enter a search for contrast enhanced mammography, and see what centers are publishing research on CEM. Many centers researching CEM are also likely to have CEM available for clinical use.
LBCA: Is CEM covered by insurance?
Dr. Covington: Generally, yes. CEM is most often billed by healthcare facilities using the same billing codes as a standard mammogram, so insurance coverage is typically available. However, this can vary by site, region, and insurance plan. It is always best to confirm coverage with an insurance provider in advance.
LBCA: Now we want to hear more about FES-PET. Can you remind our readers about what FES-PET does and how it works differently from the more commonly used FDG-PET?
Dr. Covington: FES-PET allows PET imaging of estrogen receptors. FDG-PET allows imaging of glucose (sugar) uptake. Each provides a different way of searching for cancer through PET imaging. FES-PET allows detection of cancers that express estrogen receptors, which can be very useful for many types of breast cancer including most cases of ILC. FDG-PET allows detection of cancers as they often use more glucose than many normal tissues in the body, therefore allowing glucose-hungry tumors to be detected. For ILC specifically, there will be certain cases where the lobular cancer cells do not take up much glucose but do have many estrogen receptors. Therefore, in certain cases FES-PET may reveal sites of ILC that FDG-PET may not. The reverse can also be true—sometimes FDG-PET may be better. Both studies can provide very useful information for staging various breast cancers, including ILC.
LBCA: Can you summarize how FES-PET is now included in the NCCN guidelines (pg 32 of clinical guidelines), and for what indications?
Dr. Covington: It is a huge win for FES-PET to be included in NCCN guidelines, because this formally recognizes that FES-PET may provide important information for evaluation of ER-positive cancers. The NCCN guidelines state that FES-PET/CT may be useful in certain circumstances, but do not specifically define what those circumstances are. Therefore, it is up to the referring clinician to determine whether FES-PET makes sense for a given patient. Further guidance on potential uses of FES-PET are available in the FDA label for the commercial version of FES named Cerianna, as well as from appropriate use guidelines issued by the Society of Nuclear Medicine and Molecular Imaging.
LBCA: What is the impact for patients now that the guidelines include a reference to when FES-PET/CT should be considered?
Dr. Covington: My hope is that inclusion of FES-PET/CT in the NCCN guidelines will ensure that FES-PET/CT will be available for appropriately selected patients and that more centers will start using FES-PET/CT for their patients. FES-PET/CT is not yet available at many medical centers. Having FES-PET/CT formally included in guidelines such as those from the NCCN should help increase adoption and insurance coverage for this examination and improve patient care as a result.
Disclosures: Dr. Covington is a member of the GE Fluoroestradiol Steering Committee and has received compensation for this work. Dr. Covington also has research support for contrast enhanced mammography from Fujifilm.
Readers can follow Matt on Twitter (X) @MFCovington.
