Nav: Home

History of exercise helps prevent heart disease after breast cancer

March 08, 2017

While regular exercise is recommended as part of a heart-healthy lifestyle for any person, it also appears to help mitigate the increased cardiovascular risk faced by women treated for breast cancer, according to a study scheduled for presentation at the American College of Cardiology's 66th Annual Scientific Session.

The study found that women with breast cancer who engaged in the equivalent of five hours of moderate exercise per week before their diagnosis were 40 percent less likely to have a cardiovascular event and 60 percent less likely to die from coronary heart disease compared to those with a low pre-diagnosis level of exercise. Researchers said this study is the first to examine the long-term impact of exercise before a cancer diagnosis and the cardiovascular benefits of exercise across all types of cancer treatments.

About one in eight U.S. women will be diagnosed with breast cancer during her lifetime, and these women are living longer thanks to advances in screening and treatment. Heart disease is the leading cause of death in the United States, and women who have been diagnosed with early-stage breast cancer face a markedly increased risk of heart disease compared to the general population. This increased risk, which reduces long-term survival, is attributed, in part, to cardiovascular damage from cancer therapies.

"Next to a second or recurrent cancer, heart disease is the second leading killer in cancer patients and survivors, so anything we can do to prevent cancer survivors from developing heart disease is very important," said Tochi Okwuosa, DO, a cardiovascular disease specialist at Rush University Medical Center and the study's lead author. "We found that with exercise, even before one is diagnosed with cancer, you can lower the risk of cardiovascular problems that are caused by chemotherapy and radiation therapy."

The research is based on data from the Women's Health Initiative, a large, nationwide observational study and clinical trial conducted by the National Institutes of Health from 1991-2006. Researchers extracted data from 4,015 study participants who were diagnosed with non-metastatic breast cancer. Based on physical activity questionnaires participants completed periodically throughout the study, participants were grouped into quartiles of exercise according to metabolic equivalent task (MET) hours per week, a standardized metric that reflects both the amount and intensity of exercise: low (fewer than 2.5 MET hours per week), intermediate (2.5-8.6 MET hours per week), moderate (8.6-18 MET hours per week) and high (more than 18 MET hours per week, which translates to roughly five hours of moderate exercise per week).

The researchers then analyzed cardiovascular events during an average of 12 years following participants' breast cancer diagnosis. After adjusting for age, they found that women reporting intermediate, moderate and high levels of exercise before their cancer diagnosis were 23 percent, 25 percent and 41 percent less likely to experience a cardiovascular event, respectively, compared to women reporting the lowest level of physical activity. Cardiovascular events included cardiovascular death, heart failure, heart attack, chest pain, stroke or "mini-stroke," buildup of plaque in the carotid or peripheral arteries, and revascularization procedures such as angioplasty or bypass surgery.

The results also showed women reporting intermediate, moderate and high levels of exercise before their cancer diagnosis were 41 percent, 55 percent and 60 percent less likely, respectively, to be diagnosed with coronary heart disease, a buildup of plaque in the heart's arteries, compared to women reporting low physical activity. Similar patterns were observed for all types of cancer treatment and after adjusting for a range of cardiovascular risk factors, demographic factors and medical conditions.

Radiation therapy, which in breast cancer is administered relatively close to the heart (particularly with older techniques), damages heart muscle cells and can lead to persistent inflammation many years later. This inflammation is thought to contribute to problems with the heart valves, buildup of plaque in the arteries, faulty heart rhythms and fluid buildup around the heart. Chemotherapy drugs including doxorubicin paclitaxel and others have been associated with an increased risk for heart failure and heart rhythm disorders, Okwuosa said. Even targeted therapies such as trastuzumab, now standard of care in certain types of breast cancers, can increase the risk of heart failure, while other newer therapies can cause significant hypertension, she said.

"Some of the chemotherapies can cause heart problems because the heart has very limited ability to regenerate, unlike hair can regenerate, for example, so the risk of cardiovascular issues can persist for many years," Okwuosa said. "Exercise provides a level of conditioning within our bodies which, even when we're under cardiovascular stress (such as with cancer treatments) at some later point, helps us tolerate that stress better. Exercise performed throughout one's life or even close to the time of cancer diagnosis seems to help the patient down the line with respect to the cardiovascular problems and side effects of the cancer therapy."

The study is limited by its reliance on self-reported exercise behavior rather than more objective measures. In addition, although the results suggested that women who exercised more had a lower risk of having a heart attack or being diagnosed with heart failure, those results were not statistically significant, most likely because those outcomes did not occur in large enough numbers, Okwuosa said.

Okwuosa will present the study, "Associations Between Exercise Prior to and Around the Time of Cancer Diagnosis and Subsequent Cardiovascular Events in Women with Breast Cancer: A Women's Health Initiative (WHI) Analysis," on Saturday, March 18, at 9:30 a.m. in Poster Hall C at the American College of Cardiology's 66th Annual Scientific Session in Washington. The meeting runs March 17-19.
The ACC's Annual Scientific Session, which in 2017 will be March 17-19 in Washington, brings together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCCardioEd, @ACCMediaCenter and #ACC17 for the latest news from the meeting.

The American College of Cardiology is a 52,000-member medical society that is the professional home for the entire cardiovascular care team. The mission of the College is to transform cardiovascular care and to improve heart health. The ACC leads in the formation of health policy, standards and guidelines. The College operates national registries to measure and improve care, offers cardiovascular accreditation to hospitals and institutions, provides professional medical education, disseminates cardiovascular research and bestows credentials upon cardiovascular specialists who meet stringent qualifications.

American College of Cardiology

Related Breast Cancer Articles:

Does MRI plus mammography improve detection of new breast cancer after breast conservation therapy?
A new article published by JAMA Oncology compares outcomes for combined mammography and MRI or ultrasonography screenings for new breast cancers in women who have previously undergone breast conservation surgery and radiotherapy for breast cancer initially diagnosed at 50 or younger.
Blood test offers improved breast cancer detection tool to reduce use of breast biopsy
A Clinical Breast Cancer study demonstrates Videssa Breast can inform better next steps after abnormal mammogram results and potentially reduce biopsies up to 67 percent.
Surgery to remove unaffected breast in early breast cancer increases
The proportion of women in the United States undergoing surgery for early-stage breast cancer who have preventive mastectomy to remove the unaffected breast increased significantly in recent years, particularly among younger women, and varied substantially across states.
Breast cancer patients with dense breast tissue more likely to develop contralateral disease
Breast cancer patients with dense breast tissue have almost a two-fold increased risk of developing disease in the contralateral breast, according to new research from The University of Texas MD Anderson Cancer.
Some early breast cancer patients benefit more from breast conservation than from mastectomy
Breast conserving therapy (BCT) is better than mastectomy for patients with some types of early breast cancer, according to results from the largest study to date, presented at ECC2017.
One-third of breast cancer patients not getting appropriate breast imaging follow-up exam
An annual mammogram is recommended after treatment for breast cancer, but nearly one-third of women diagnosed with breast cancer aren't receiving this follow-up exam, according to new findings presented at the 2016 Annual Clinical Congress of the American College of Surgeons.
Low breast density worsens prognosis in breast cancer
Even though dense breast tissue is a risk factor for breast cancer, very low mammographic breast density is associated with a worse prognosis in breast cancer patients.
Is breast conserving therapy or mastectomy better for early breast cancer?
Young women with early breast cancer face a difficult choice about whether to opt for a mastectomy or breast conserving therapy (BCT).
Breast density and outcomes of supplemental breast cancer screening
In a study appearing in the April 26 issue of JAMA, Elizabeth A.
Full dose radiotherapy to whole breast may not be needed in early breast cancer
Five years after breast-conserving surgery, radiotherapy focused around the tumor bed is as good at preventing recurrence as irradiating the whole breast, with fewer side effects, researchers from the UK have found in the large IMPORT LOW trial.

Related Breast Cancer Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#529 Do You Really Want to Find Out Who's Your Daddy?
At least some of you by now have probably spit into a tube and mailed it off to find out who your closest relatives are, where you might be from, and what terrible diseases might await you. But what exactly did you find out? And what did you give away? In this live panel at Awesome Con we bring in science writer Tina Saey to talk about all her DNA testing, and bioethicist Debra Mathews, to determine whether Tina should have done it at all. Related links: What FamilyTreeDNA sharing genetic data with police means for you Crime solvers embraced...