Protecting the Heart: Cardiovascular Risks Decline, but Vigilance is Warranted

In the pursuit of malignant tumor cells, normal tissues and organs get caught in the crossfire of cancer treatment. This has been especially true of the heart. In earlier decades, radiation to the chest could carry deadly cardiovascular risks. Newer treatment methods, however, are putting the odds in patients’ favor.

Lori Jo Pierce, M.D.

Lori Jo Pierce, M.D.

“Technological advances now allow doctors to minimize cardiovascular risks of radiation therapy,” says Lori Jo Pierce, M.D., a U-M professor of radiation oncology. Her research focuses on the use of radiation therapy in the multi-modality treatment of breast cancer. Dr. Pierce is participating in the Cancer Center’s 2013 Breast Cancer Summit 2013 as a panel speaker on “Research: What questions are we trying to answer?”

Dr. Pierce recently talked with mCancer Partner about how technological advances help to minimize cardiovascular risks to breast cancer patients, and gave a research update on a related study.

mCancer Partner: Who is at risk for radiation associated heart disease?

Dr. Pierce: Anyone who is receiving radiation to the chest could be at risk for radiation-associated heart disease so it is important to shield the heart from the radiation beam. Patients treated with radiation for Hodgkin’s disease in the past were potentially at risk for cardiac disease depending upon the location of the blocks used to protect the heart. Women treated for left sided breast cancer are carefully monitored and planning is done to minimize the heart from being in the radiation field as they, too, could be at risk.

mCancer Partner: What types of heart problems might patients experience after treatment?

Dr. Pierce: Pericarditis (inflammation of the lining around the heart) has been seen in patients treated for Hodgkin’s disease. Arrhythmias (erratic heart beats) have also been reported. But the condition we are most concerned about is the development of or the progression of coronary artery disease. Some of the coronary vessels are located near breast tissue and therefore are located close to areas commonly irradiated in women with breast cancer. These vessels were shown to be particularly vulnerable in patients treated with older radiation techniques.

mCancer Partner: Have newer treatment methods reduced the risk for cardiac side effects?

Dr. Pierce: Current radiation techniques have dramatically reduced the risk of heart-related toxicity but we are always mindful of the potential risk, particularly in women with left-sided breast cancer. Multiple recent studies show minimal differences in the incidence of cardiovascular disease among patients who were treated for left-sided breast cancer compared to those treated for right-sided disease. The data following treatment with more modern techniques suggest that the techniques currently in use spare the heart much more than with earlier treatment approaches.

mCancer Partner: How do new techniques minimize risk?

Dr. Pierce: Computerized three-dimensional planning allows us to see exactly where the heart is positioned and set up radiation fields so we can minimize the exposure of the heart to the radiation beam. In this day and age, many of our patients are receiving other curative treatments such as Adriamycin and Herceptin that in some patients can cause cardiac damage. So for many reasons, our goal in radiation oncology is to deliver radiation as safely as possible to minimize further cardiac injury. We are continuing to study the best ways to do that.

mCancer Partner: How are you studying this?

Dr. Pierce: We recently completed accruing patients to a study examining two radiation techniques used to treat left-sided breast cancer to determine whether one treatment could further reduce radiation exposure of the heart compared with the other. The study compared baseline heart and lung function before treatment and then again one year after treatment. By comparing these results, we hope to determine if one treatment can further decrease exposure of the heart and lungs to radiation. The last of the patients enrolled on the study will be having their one-year scans later this year and we will then analyze our results.

mCancer Partner: Can people who may be at risk for cardiovascular side effects do anything to lower their risk?

Dr. Pierce: Talk to your primary care physician about your cardiac health. Find out from your oncologist whether any of your treatments carry increased risk for cardiovascular problems and share this information with your regular doctor. If you have hypertension, make sure to treat it. Discuss risks that may be associated with a family history of heart disease. Exercise, eat a heart-healthy diet and think in terms of overall health maintenance.

About the Breast Cancer Summit 2013:

The program is hosted by the University of Michigan Comprehensive Cancer Center Breast Oncology and Community Outreach Programs, with support from the Mid-Michigan Affiliate of Susan G. Komen for the Cure and the University of Michigan School of Public Health.

WHEN: Saturday, April 20, 2013, 10 a.m. – 3 p.m.

WHERE: Washtenaw Community College
Morris Lawrence Building
4800 E. Huron River Drive
Ann Arbor, MI 48105

Registration Required by April 5! To register, please use our online form or call  734-998-7071.


Breast Cancer/Heart Health Resources:

U-M Comprehensive Cancer Center/Patient Education Research Center: Radiation Therapy Information Guide

National Cancer Institute: Radiation Therapy for Breast Cancer Now Less Risky for Heart