Survival
rates after breast cancer have improved substantially due to advances in
screening and treatment. Yet, many treatments can damage the heart, resulting
in a three-fold higher risk of heart failure. While we know there is an
increased risk of developing heart disease for breast cancer survivors, there
is not much data available about how to properly screen for and manage this
risk.
“Most
of the information we currently have indicates that many breast cancer
survivors can be left with a weakened heart following chemotherapy, but we
don’t really know much about the long-term risk of serious heart disease,” says
Dr. Husam Abdel-Qadir, scientist at Women’s College Research Institute (WCRI)
and cardiologist at Women’s College Hospital (WCH). “It is possible that this
risk of serious heart disease is not as irreversible as we think as long as we
are able to implement more effective prediction and management strategies for
these patients.”
Despite
the perceived necessity of cardiac imaging before and during chemotherapy, the
recommendations for their use are mostly based on expert opinion rather than
data. In a pilot study, Dr. Abdel-Qadir found that only three per cent of
routine cardiac imaging tests provided to breast cancer patients getting a
treatment called trastuzumab (or Herceptin®) led to a change in their care.
Furthering these findings, the Wholesale
cardiac Imaging Surveillance with Echocardiography and Radionuclear assays
during breast cancer chemotherapy (WISER)study led by Dr. Abdel-Qadir is using data collection to determine
if these tests are an efficient use of healthcare resources and patients’ time.
“The
WISER study will be the first to investigate on a large scale whether cardiac
imaging performed while receiving certain types of chemotherapy is useful in
making treatment decisions,” adds Dr. Abdel-Qadir. “We hope that data from the
WISER study will allow us to pick and choose tests more appropriately based on
individual risk, rather than the current one-size-fits-all method.”
Dr.
Abdel-Qadir and his colleagues also recently developed a prediction model that
estimates the probability of major adverse cardiovascular events, such as
hospitalization or death, within five to 10 years of chemotherapy based on a
woman’s age and risk factors. With improved screening and prediction models,
clinicians will be able to determine measurable risk for heart disease to
better guide their decision-making during cancer treatment.
Care
after chemotherapy is another area of focus for Dr. Abdel-Qadir, as heart
disease among women who are breast cancer survivors may not progress to serious
heart failure unless they also have other risk factors, like pre-existing heart
disease, hypertension or diabetes. In order to better understand how heart
disease develops following chemotherapy, Dr. Abdel-Qadir and multiple partners
across WCH have launched Diabetes,
Inflammation, left ventricular dysfunction And Lifestyle After Breast Cancer (DIAL-ABC).
The study will also examine how exercise-based cardiac rehabilitation may
reduce that risk. DIAL-ABC is a collaboration at WCH between the cardiology
division, endocrinology division, After Cancer Treatment Transition (ACTT)
clinic and the Women’s Cardiovascular Health Initiative (WCHI). Breast cancer
survivors will be invited to enrol in DIAL-ABC when they visit the ACTT clinic
following their cancer treatment. Participants will then join the preventative
cardiac rehabilitation program offered through the hospital to help them
establish long-term lifestyle changes to hopefully reduce their risk of
developing heart disease.
“Programs
like DIAL-ABC can help us change how we approach care for breast cancer
survivors,” notes Dr. Abdel-Qadir. “If we are able to effectively manage the
risk of heart disease in this population through preventative strategies such
as cardiac rehab, this would have great implications on which cancer treatments
we choose for patients. My hope is that this research is able to shift our
focus from worrying about using certain types of chemotherapy because they may
damage the heart to providing the best treatment for curing a patient’s cancer,
followed by prevention and management of potential future heart disease.”
