Dr. Heather Parsons of Dana-Farber Answered Questions About Breast Cancer

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Discussion on follow up testing, the role of MRI, genetic testing, screening, bio-marker testing, and CDK4/6 inhibitors.

Dr. Heather Parsons of Harvard Medical School and Dana Farber Cancer Institute recently answered submitted questions about breast cancer treatment. Many of these are being discussed in the Breast Cancer Community on CancerConnect. CancerConnect is a safe and private online support community for cancer patients and caregivers.

What is appropriate FU for DCIS, LCIS treated with surgery or radiation?

Patients with LCIS are now considered separately from patients with DCIS and should see a practitioner for a breast exam regularly. They may consider additional breast cancer risk reduction together with their provider, depending on their particular history. Patients with history of DCIS who have undergone surgery and/or radiation should see a provider every six to twelve months for a physical and history for five years and then annually. They should undergo annual mammogram. Depending on the particular features of their DCIS, they may also be eligible to receive endocrine therapy to reduce the risk of developing breast cancer recurrence or a new breast cancer.

I'm concerned about how I should be screened for reoccurrences since I'm only being followed with yearly mammograms. My understanding is that unlike the more prevalent ductal breast cancer, lobular doesn't tend to form lumps so can be difficult to detect on mammograms. Mine was only found on an MRI as I was being followed for DCIS.

While it is true that lobular breast cancers can be more difficult to detect on mammograms initially, follow up with mammogram remains the best way to look for recurrences in the breast. Patients with a history of breast cancer should also see their provider every six to twelve months for a history and physical, which should include a breast exam.

Each patient’s follow up plan may be slightly different and should be tailored to their particular situation, but here are some general guidelines. After completion of treatment for breast cancer, patients should see their provider every four to six months for five years, and then annually. They should have a history and physical at these visits, and this should include a breast exam. Patients should undergo mammograms of the remaining breast(s) annually, with some higher risk patients also needing MRI. We do not recommend checking tumor markers after completing treatment, as they are not very sensitive or specific for detecting recurrence. A positive test can be falsely elevated, causing significant, unnecessary anxiety. A negative test can often be incorrectly negative, providing false reassurance. Patients often ask about ongoing body scans after a diagnosis of breast cancer. Studies in patients with breast cancer have shown that doing regular interval scans to look for cancer sooner did not ultimately help patients do better. Therefore, we only recommend scans in the presence of a new, concerning sign or symptom.

When should ultrasound or MRI be used instead of or in addition to mammography?

Mammogram is the main test we use to look for a new breast cancer or recurrence of cancer in the breast and should be done annually. Patients who have a lifetime risk of new breast cancer that is 20 percent or greater, based on genetic mutations, family history or other factors should undergo annual MRI screening. If you wonder whether you have a lifetime risk that is high, it is something that can be discussed with your primary care doctor or oncologist. Ultrasound is often used as a supportive test together with mammography or to evaluate a new finding such as a lump but is not recommended as a breast screening test by itself.

When should the Oncotype test be used?

Oncotype DX is a genomic test performed on a sample of estrogen receptor (ER)-positive breast cancer that gives us two important pieces of information: how likely a cancer is to respond to chemotherapy, and how likely a cancer is to recur after initial treatment. We use this test when we are making a decision about whether chemotherapy is likely to add benefit for a particular patient. A lower score is associated with less benefit, while a high score is associated with more benefit. If you have ER-positive breast cancer, it is important to discuss with your oncologist whether an Oncotype test is likely to add helpful information for you.

Should all women diagnosed with breast cancer undergo BRCA or other genetic testing?

The American Society of Breast Surgeons recently recommended all patients with breast cancer should be offered genetic testing that includes BRCA1, BRCA2 and PALB2, three genes for which there are strong links between their alteration and risk of breast cancer. However, this recommendation has not been universally endorsed by other professional groups. But as our knowledge of hereditary cancer improves, as genetic counseling becomes more available, and as testing becomes cheaper, we are moving toward a model of universal testing. Right now, we strongly recommend genetic counseling and testing for patients who meet any of these criteria: early age at breast cancer diagnosis; triple negative breast cancer; metastatic or advance breast cancer; bilateral breast cancer; a strong family history of breast, ovarian, pancreas and/or prostate cancer; and women of Ashkenazi Jewish ancestry. Finally, though the BRCA1 and BRCA2 genes are well-studied, there are many other genes for which we know there is a link between alterations and breast cancer risk, but exact risk is not well understood. This complicates our counseling of patients with genetic testing findings to best educate them and their families about potential risk.

For patients with HER2-negative, ER-negative, PR-negative breast cancer, commonly called “triple negative” breast cancer (TNBC), chemotherapy is the mainstay of systemic treatment in 2019. Research into a better understanding of this type of breast cancer and into other, more targeted treatments continues and is a high priority for many in the field. For patients with stage III TNBC in the United States, without heart or other serious health problems, a regimen of dose-dense doxorubicin/cyclophosphamide followed by paclitaxel or “ddAC-T” is the standard treatment. It is important to talk to your physician about your specific situation and options.

Is there any role for the newer biomarker analysis for post-treatment patients with ER/PR+, Her2Neg BC? To target possible future treatment for relapse or prevent recurrence?

For patients who have completed definitive treatment for hormone receptor(HR)-positive stage I-III breast cancer who may also remain on hormonal therapy, there are not currently any blood-based biomarkers that we recommend. This is an exciting area of active research, and in the future we may have biomarkers to help us determine whether someone is at risk for recurrence. This may help us better direct a patient’s treatment. We also hope this type of test will help to prevent recurrence by directing more effective therapies when the level of cancer is lowest – detectable via a blood test, but not yet detectable on scans.

What biomarker testing should be performed in metastatic breast cancer?

Biomarkers can be helpful in metastatic breast cancer in a few ways. Traditional breast cancer biomarkers such as CA15-3, CA27-29 and CEA, are proteins secreted by a patient’s cancer that may be detectable in the blood. It is important to know that some cancers do not produce them, and in these cases they are not very helpful. If they are detectable, they can be tracked over time to help determine - together with other information such as symptoms and imaging - whether a cancer is responding to treatment.

Another type of biomarker is a test of circulating tumor cells, or CTCs. CTCs are cells found in the bloodstream that are given off by a patient’s cancer. Higher CTC levels are associated with worse prognosis. Some studies show that a decrease in CTCs after starting on a new treatment is associated with response to the treatment, but other studies have not shown the same. I do not typically check CTCs in my practice.

Finally, we now have tests that can analyze the circulating tumor DNA (ctDNA) found in the blood of a patient with cancer. These tests – such as FoundationOne Liquid or Guardant360 – analyze tiny bits of code, or DNA, found in the blood to look for alterations that may provide a treatment target for a patient’s cancer. In breast cancer, there are not currently many treatments that are directed specifically by these alterations. But as research continues and new treatments emerge, this type of test may become increasingly important.

I have advanced breast cancer when should Ibrance or Kisqali be used?

Ibrance (palbociclib) and Kisqali (ribociclib) and Verzenio (abemaciclib) are three very similar medications known as CDK4/6 inhibitors. They are now first-line treatment options for patients with advanced hormone receptor (HR)-positive breast cancer and are typically given together with hormonal therapy. They are medicines that in multiple, large studies have been shown to significantly increase the time a patient with HR-positive breast cancer can remain on the same treatment regimen. They are very well tolerated, though some patients may experience side effects such as lowering blood cell counts, fatigue, diarrhea, and others. Because of this, some patients may benefit from waiting to use one of these medicines until their second treatment line for advanced breast cancer. These drugs are also being studied in earlier stage, high risk disease, and in other breast cancer subtypes.

This Ask the Expert Series is made possible through support from the Personalized Medicine Foundation, CancerConnect and the Dana-Farber Cancer Institute. Ask the Expert content and programs are not intended to be a substitute for healthcare professional medical advice, diagnosis, or treatment. Information should be used to further an individuals discussion with their managing healthcare team or providers. Speak to your healthcare provider about any questions you may have regarding your health.

About Dr. Parsons M.D. MPH

Heather A. Parsons, MD, MPH is a medical oncologist at Dana-Farber Cancer Institute (DFCI) and Instructor of Medicine at Harvard Medical School. Her research focuses on breast cancer and the use of blood-based genomic biomarkers to understand the course of a woman’s breast cancer and response to treatment. Ultimately, she aims to develop these biomarkers to better direct existing treatments, to avoid over treatment, and to develop new treatments to help patients live better, longer lives.

Dr. Parsons is a graduate of Dartmouth College and has a Master of Public Health from Johns Hopkins Bloomberg School of Public Health. She received her medical degree from Drexel University College of Medicine, where she was inducted into the AOA Honor Medical Society. She was then an Osler Medicine resident in Internal Medicine at The Johns Hopkins Hospital. She completed a fellowship in Medical Oncology at Johns Hopkins Hospital before joining the Susan F. Smith Center for Women’s Cancers at DFCI. She is currently an instructor at Harvard Medical School. Dr. Parsons cares for patients with breast cancer as a medical oncologist at DFCI. Her research focuses on the use of blood-based biomarkers to understand – and in doing so to better treat – patients with breast cancer. She is supported by awards from the Susan G. Komen Foundation and the Terri Brodeur Breast Cancer Foundation.

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