DEAR DOCTOR K: I survived cancer, only to be told that the treatments that saved my life may have increased my risk for cardiovascular disease. What are the risks? And can I minimize them?
DEAR READER: As more people are living longer after a cancer diagnosis, more people are coping with the long-term effects of cancer treatment. Many cancer-suppressing treatments can have undesirable effects, for example, on the heart and blood vessels.
I spoke to my colleague Dr. John Groarke, a cardio-oncologist at Harvard-affiliated Brigham and Women’s Hospital. Experts in this field focus on promoting heart health in people with cancer, both during and after their treatment. He noted that, as with most treatments, there are some risks as well as benefits — and that the possible risks always need to be balanced against the benefits.
There can be adverse effects from cancer treatments on the heart and blood vessels, ranging from negligible to very serious. Of course, I don’t know what treatments you received, so I’m able to make only general statements.
People treated during childhood or after age 65 are more prone to heart issues from cancer therapy. And certain chemotherapy drugs are more harmful than others.
Newer, targeted cancer therapies tend to have fewer side effects than older chemo drugs. But these newer drugs, which disable genes or proteins that cancer cells need to grow, can also affect cells in the heart and blood vessels and diminish the heart’s pumping power.
Another group of targeted therapy drugs slow the growth of new blood vessels that feed tumors. But they may also raise blood pressure and prevent the growth of new blood vessels in parts of the heart that are starved for blood.
Heart damage from radiation therapy to the chest usually takes years to show up. Radiation can cause heart tissue to scar or stiffen. This may lead to valve or heart rhythm disorders, coronary artery disease or heart muscle disease. Women with breast cancer who receive radiation therapy face a slightly higher risk of a heart attack.
Heart dangers are magnified in cancer survivors who:
- received both chemotherapy and radiation;
- have recurrent cancer;
- have pre-existing heart disease.
As for what you can do, medications can help prevent or treat heart effects from chemotherapy. All cancer survivors should stay vigilant for any new cardiovascular symptoms. If you experience shortness of breath, weakness, fatigue or a rapid, irregular heartbeat during or after treatment, report them to your doctor right away.
You already have had cancer, and received treatment. For other readers who may be told in the future that they have cancer, here are some direct questions to discuss with a doctor:
Will the treatment cure the cancer, or just postpone death? If it won’t be a cure, by how long will it postpone death? Will treatment improve cancer symptoms, now or in the future? And what are the side effects of treatment, including, but not limited to, heart problems?
Of course, the doctor’s answers can only be estimates. But people need that information to know which choice is right for them.