Dangerous cardiovascular complications are becoming increasingly evident in cancer patients and survivors. Older radiation therapy techniques and numerous cancer drugs can injury the heart and coronary arteries, leading to serious medical conditions that if not identified and managed appropriately can decrease both quality of life and survival.
Types of Heart Injury From Cancer Treatment:
The most common cardiovascular complications diagnosed after cancer treatment with therapies that are toxic to the heart are:
- heart failure (HF)
- left ventricular dysfunction (LVD)
- myocardial ischemia
- hypertension (HTN)
- thromboembolism
- QT prolongation
- bradycardia
Heart Toxic Cancer Drugs:
Cancer drugs such as anthracylines (i.e. Adriamycin), tyrosine kinase inhibitors (i.e. Gleevec, Sutent) and targeted antibody therapies (i.e. Herceptin) can cause or exacerbate heart failure, and drugs that block the development of blood vessels to tumors (i.e. Avastin, Nexavar, Votrient) can lead to dramatic rises in blood pressure (as well as: hemorrhage, thrombosis, nephrotoxicity and cardiotoxicity.) Patients need to be carefully watched during and after treatment with these medications for the development of these potentially serious side effects. In a recently published study of 8,400 breast cancer patients treated with either chemotherapy drugs called anthracyclines or a targeted therapy called trastuzumab, 1,028 (12%) developed heart problems within three years, and 345 (34%) saw a cardiologist within 90 days of their heart diagnosis. Women with heart failure after cancer treatment were more likely to be treated with standard medications if seen by a cardiologist compared with those who did not see a cardiologist.
Radiation Injury To The Heart:
Radiation therapy to the chest (from treatment of lung, breast and esophageal cancers, lymphomas, etc.) can cause injury to heart muscle and coronary arteries potentially leading to the development of: inflammation/injury to heart muscle (cardiomyopathy), inflammation/injury of the outer lining of the heart (pericarditis), irregular heart beats (arrhythmias) and coronary atherosclerosis. These complications can occur months to decades after treatment, and therefore need to be carefully monitored throughout one’s life.
Suboptimal Cancer Treatment is Not Uncommon in Patients With Pre-Existing Heart Disease:
Cancer patients with existing cardiac conditions often do not receive intensive cancer treatments that may exacerbate their known cardiovascular problems. This can lead to suboptimal treatment of their cancer, particularly if the drug that was not offered (or given in a lower dose) is the most effective therapy available for their cancer. Furthermore, patients who are under the care of a cardiologist for an existing cardiovascular problem who then develop cancer often receive less aggressive cardiac therapies as their cancer is assumed to be the more pressing medical issue. This is particularly poignant, as patients with a history of early-stage breast cancer are more likely to die from cardiac disease than from their cancer.
Longterm Cardiac Follow Up is Essential
As an integrative oncologist, I counsel all of my patients on the importance of longterm follow-up and monitoring for the potential development of cardiac problems. Depending on the specifics of the cancer treatment received, the risks, typical time of onset after treatment and type of injury are well-known to oncologists and cardiologists who specialize in cancer patients (“cardioncologists“). Primary care physicians may not be aware of these risks due to their limited training in these issues. In fact, in one recent study of over 1,000 primary care providers, researchers found that only 6% of them were able to identify the main long term side effects of 4 commonly used chemotherapy drugs. For this reason, it is important to continue longterm follow-up with your oncologist and/or cardiologist.
Cardiotoxicity: a common side effect of chemotherapy video
http://youtu.be/qouL3UamfzU
What Can You Do?
The most important thing you can do is to discuss with your oncologist the potential risks of cardiac toxicity from your treatments. Depending on your risk, you may need to establish lifelong follow-up with your oncologist and your cardiologist (if needed.) The next most important thing you can do is to stay physically active! If you are healthy enough to exercise (if you don’t know, ask your doctor) it is essential that you do so. This will improve your overall quality of life, potentially lead to a reduced risk of cancer recurrence and reduce your risk of dying from cardiovascular disease. Read our article on this subject to learn more:
Exercise and Cancer 101: Why You Should “Just Do It!”
Additional References:
- Cardiovascular Complications of Cancer Therapy : Incidence, Pathogenesis, Diagnosis, and Management (Journal of the American College of Cardiology)
- The Compelling Need for a Cardiology and Oncology Partnership and the Birth of the International CardiOncology Society (Journal of the American College of Cardiology)
- Cardiac Disease in Cancer Patients: An Overview (Journal of the American College of Cardiology)
- What is Cardiac Toxicity (or Cardiotoxicity)? (National Comprehensive Cancer Network)
- Monitoring and Managing Cardiotoxicities Associated with Cancer Therapies: An Expert Interview with Dr. Pamela S. Douglas (Duke Medical Center in Durham, North Carolina)
- Cardiotoxicity of radiation therapy for malignancy (UpToDate)
- Cardiotoxicity of anthracycline-like chemotherapy agents (UpToDate)
- Cardiotoxicity of nonanthracycline cancer chemotherapy agents (UpToDate)
- Cardiotoxicity of trastuzumab (UpToDate)
