Reports from the American Heart Association have caused increased awareness that many breast cancer treatments may result in heart disease and heart failure in the long term. These reports have understandably triggered many questions and concerns for breast cancer survivors.
Certain chemotherapy drugs, as well as radiation therapy, are known to carry some cardiac risk. However, some measures can be used to lower the risk of heart damage in breast cancer patients receiving radiation. This is particularly important in patients with left-sided breast cancer.
Technological Advances
Significant advances in radiation therapy over the years have brought about considerable improvements in long term outcomes. Thanks to technological advances, radiation doses are now lower and much more targeted. Computerized treatment planning, specialized equipment, and enhanced delivery methods provide greater accuracy, the ability to track heartbeats and lung movement, allow us to provide superior quality treatments, and better protect these critical organs from unnecessary radiation.
Simple patient positioning changes, such as having the patient lie on her stomach during treatments, have the potential to limit the amount of radiation that unintentionally travels to the heart. However, this process has other challenges, such as an inferior degree of reproducibility on a daily basis as well as poorer patient comfort. Another technique used to decrease the heart dose is called Deep Inspiration Breath Hold, where the patient is taught to hold her breath in deep inspiration, thus moving the heart away from the field of treatment.
Using Proton Therapy for Breast Cancer
It is advantageous to understand the different forms of radiation available as this can alter radiation dose distribution not only to the target area but also to adjacent critical organs in the body. The use of proton therapy is an enormously effective approach to protecting the heart and other vital organs compared to conventional radiation methods. Protons are positively charged particles and are physically different from traditional X-ray radiation, having the ability to precisely target the tumor site with virtually no radiation affecting the heart and lungs.
As part of a research team that analyzed trends in cardiac biomarkers following adjuvant proton therapy for breast cancer, my team monitored troponin T (a protein released into the blood when the heart sustains damage) and proBNT (a hormone produced by the heart and released in response to pressure changes within the heart) levels and found there were no changes to indicate injury to the heart with proton therapy.
While women preparing for breast cancer treatment should be aware of the associated risk between radiation therapy and heart disease, they should not be deterred from receiving radiation. Early-stage breast cancer treated with lumpectomy and radiation has proven to be as effective as mastectomy. Studies have also shown cancer recurrence was reduced in women with early-stage breast cancer with one to three positive lymph nodes who received radiation following a mastectomy.
I advise women to have their heart health evaluated and make their doctors aware of any heart disease risk factors they may have before starting breast cancer treatment. Through treatment and beyond, maintaining a heart-healthy lifestyle that includes regular exercise and a healthy eating plan is good for your heart and your health. If you have questions about breast cancer treatment and heart disease risk, please e-mail me at jyotimd@ackermancancer.com.
-Dr. Babita Jyoti, M.D.
