Late cardiac side effects of Hodgkin's treatment
Dear OncoLink "Ask The Experts,"
Mitchell Machtay, MD, Assistant Professor of Radiation Oncology at the Hospital of the University of Pennsylvania and Deputy Chairman of Radiation Therapy Oncology Group, responds:
When first recognized as a distinct type of illness in the 1800's, Hodgkin's Disease was almost universally fatal. Since that time there have been tremendous advances in the treatment of this cancer - perhaps more than against any single type of cancer. These improvements in treatment are largely due to the dramatic effectiveness of radiation therapy and chemotherapy against Hodgkin's Disease. There is an ever-growing population of HD survivors, many of whom were treated, like yourself, quite a few years ago.
The downside of this success, unfortunately, is the recognition of "late" side effects of cancer treatment, predominantly (but not entirely) due to radiation therapy. The most worrisome long-term risks after radiation to the chest are heart problems and the development of new cancers (such as breast or lung cancer). In any one person who had chest radiation and suffers a heart or lung problem 20 years later, there is no proof of a cause and effect. Heart disease is extremely common in people of all walks of life, especially as we age. Nonetheless, one paper on the subject, written by experts at Stanford University*, suggests that people who have had chest (mantle) radiation for Hodgkin's disease have about a three-fold increase in the risk of a fatal heart attack over the next several decades (compared to the risk in the general population). The numerical risk of dying from a heart attack was about 4% in this highly publicized study. This is very significant and disturbing data, but much of it reflects radiation technology from the pre-1980's, when radiation doses to the heart were a lot higher than in more recent years.
Whether one was treated for Hodgkin's Disease in 1960 or 2000, there is no way to "take back" the radiation dose that was given. And even the most modern and sophisticated radiation planning cannot completely avoid some radiation exposure to the heart while still irradiating the diseased lymph nodes of the chest. Long-term radiation risks to the heart may include coronary artery disease (the hardening and fat deposits in the arteries that can lead to heart attack), pericarditis (irritation of the heart lining), leaky heart valves, arrhythmias (irregular heartbeat), and/or congestive heart failure (poor pumping strength of the heart). As you have noted, these can be the results of scars left behind from radiation. So what steps can a HD survivor take to minimize his/her risks?
First, it is important to understand that these problems do not happen to everyone who has had chest radiation - it would be counterproductive to panic. I think it is extremely important, however, that Hodgkin's Disease survivors pay even closer attention than the general public to other risk factors for heart disease. These of course include strict 100% abstinence from smoking, maintaining a good diet and body weight, alcohol in moderation, regular exercise, monitoring blood pressure (and appropriately treating high blood pressure if present) and monitoring cholesterol levels (and treating abnormal cholesterol levels if present). At minimum I would recommend a very thorough annual physical examination and comprehensive blood testing by an excellent family physician or internist. Periodic electrocardiograms and chest x-rays are also appropriate, and I recommend that many patients consider taking a baby aspirin a day (unless there is some reason they can not take aspirin). I think it's important to point out that cancer survivors need to have a solid relationship with a primary physician/internist in addition to their cancer doctor(s) precisely for these kinds of issues.
In the absence of any unusual signs or symptoms (such as chest pain/pressure or shortness of breath) it is unclear if additional testing adds anything other than anxiety. There have been tremendous advances in cardiovascular testing, imaging and treatments, so some long-term Hodgkin's survivors may want to consider obtaining a formal consultation with a cardiologist if they are concerned about the risk of heart problems. But talk with your primary physician and/or cancer doctor(s) first.
Many congratulations on reaching your 15-year milestone and please look forward to many more decades of health and happiness.
* Hancock SL, Tucker MA, Hoppe RT. Factors affecting late mortality from heart disease after treatment of Hodgkin's disease. JAMA 1993; 270(16): 1949-1955.