According to the WHO, breast cancer is the leading cancer among women globally. In both the US and the UK, an estimated 12% of women will be diagnosed with the disease at some point in their lives. Some of the most commonly used cancer treatments include surgery, radiation therapy, immunotherapy, chemotherapy, hormone therapy and precision medicine.
Thanks to investment in research for new treatments, we’ve seen breast cancer survival rates triple in the last 30 years. However, a new study carried out by the American Heart Association has warned that breast cancer patients might be at an increased risk of cardiovascular diseases.
Heart disease is the top cause of death in the US, and it’s feared that current treatments might be having a negative impact on women’s health.”For older women, (cardiovascular disease) poses a greater mortality threat than breast cancer itself. This is the first scientific statement from the American Heart Association on CVD and breast cancer,” the American Heart Association says.
However, the researchers also noted that breast cancer and heart disease already have numerous common risk factors like age, obesity and other lifestyle factors. Patients are being urged to try and reduce their risks by monitoring their blood pressure and cholesterol, as well as maintaining and healthy diet and taking regular exercise.
“We hate to trade one disease for another,” said Dr. Laxmi Mehta, an author of the statement and director of the Women’s Cardiovascular Health Program at The Ohio State University Wexner Medical Center. She added “We are still recommending that patients do get their breast cancer treatment. They should get the best treatment that’s necessary for their breast cancer.”
“Oncologists are doing a terrific job of increasing survival rates by advancing the science and improving cancer treatments. This is much better than a few decades ago,” she said. “But there are side effects from these cancer treatments, and we’re trying to recognize it in the very early phases so that we may be able to mitigate the heart effects and avoid significant heart damage.”
According to Dr. Otis Brawley, chief medical and scientific officer and executive vice president of the American Cancer Society, who was not involved in the study, the connection between breast cancer and cardiovascular disease has been known for some time by oncologists. It’s believed that both radiation therapy and chemotherapy can both pose a risk to cardiovascular health.
“We have taught and seen these problems. The report may bring this problem to the front of mind among emergency medicine and internal medicine doctors who are caring for these women,” he said. “Let’s give these drugs and treatments to people who need them — the risk-benefit is more favorable — and let’s do all we can to determine who is unlikely to benefit from the drugs and spare them the risks.”
A previous study in 2013 also found that the risk of heart disease increases by up to 7.4% through exposure to radiotherapy. The study also found that women who had cancer of the left breast had a significantly higher risk of developing cardiovascular problems than those with cancer of the right breast.
“It is less a problem today than 20 years ago, because we started aiming the beam to miss the heart about 20 years ago, but we occasionally see a woman who had lumpectomy and radiation, and the radiation beam caught part of the heart and a coronary artery,” Brawley said. “This can cause isolated coronary artery disease in that portion of the artery.”
Another study carried out in Dundee, Scotland found that those who took anthracyclines as their only form of treatment were more likely to develop left ventricular systolic dysfunction, which of a common cause of heart failure. “Adriamycin, or doxorubicin, and trastuzumab, or Herceptin, are the big causes of heart failure,” Brawley said.
“Adriamycin-induced congestive heart failure symptoms can show up three to five years after treatment and easily be missed by an internist or ER doctor who does not see a lot of these patients,” he said. “Health care is changing such that a cancer patient often does not see an oncologist after completion of therapy,” he added.
According to Dr. Lewis Kuller, professor at the department of epidemiology at the University of Pittsburgh Graduate School of Public Health who was not involved in the study, the new statement from the American Heart Association is “long overue”. He added that both men and women should be encouraged to maintain healthy lifestyles in order to reduce the risks of cardiovascular problems like heart attacks and strokes.