Are You Actively Addressing Cardiac Risks in Your Cancer Patients?

As people survive longer with cancer, including thyroid and other endocrine-related types, they face the added risk of cardiovascular disease morbidity and mortality, requiring ongoing clinical vigilance.

with Justin Floyd, DO, and Eiman Jahangir, MD, MPH

Nearly half of the population in the United States will be living with cancer at some point in their lives, a number growing at a faster clip than the number of those diagnosed.1 While this trend may seem like good news, the success of cancer treatment has revealed a different problem associated with survival—a higher risk of cardiac disease.2

A cancer diagnosis can be shocking, said Justin Floyd, DO, FACOI, a medical oncologist at the Cancer Care Specialists of Illinois in Swansea, “so much so that it may overshadow everything else but as patients move toward remission or a cure, the cardiac dangers will begin to outpace the prior cancer.”

Cancer patients need to be actively managed for their cardiovascular disease risks.

Cancer Treatments Present Lasting Cardiovascular Disease Risk

Traditional treatments, including radiation and chemotherapy, and newer targeted treatments, such as kinase inhibitors, are known to cause cardiotoxicity (ie, heart failure, myocardial ischemia, hypertension, and thrombogenesis).

For some, particularly women, the risk of cardiovascular disease is higher than the risk of the breast cancer recurrence.3 Researchers have cited numerous side effects of cancer treatments, impacting blood supply, cell division, and cell death, which collectively have a particularly large impact on the cardiovascular system;3-6, and when patients have multiple treatments, effect on the circulatory are heightened.7

Anthracyclines, commonly used chemotherapeutics agents (ie, doxorubicin) have particularly elevated risk of cardiac repercussions. For example, a standard dose of doxorubicin raises patients’ risk of heart failure by 5%, but these risks may occur even at lower doses.4

Other chemotherapies have been noted to increase the risk of cardiotoxicity: cyclophosphamide, cisplatin, ifosfamide, and taxanes; and, fluoropyrimidines may lead to coronary vasospasm.8,9

Risk of Cardiac Events Linger for Years After Cancer Therapy

Cardiovascular issues may arise during the first year post-treatment or present years later, however, there is little understanding to explain the variation in timing. Findings from an older study indicated that 38% of patients treated with anthracycline show evidence of heart disease more than 10 years after treatment (as compared to 18% within the first 10 years).10

The newer targeted therapies, such as rituximab, trastuzumab, and ibrutrinib, have not had the duration under study of other agents, yet there are already indications of increased cardiac risks such as heart failure, stroke, and ventricular enlargement.6-8

Women appear to have specific cardiac risks not apparent in men, possibly attributed to a higher percentage of body fat and/or higher drug concentrations, which were calculated based height and weight, regardless of the percentage of lean to fatty tissue.11

Reducing Cardiac Risks Require Equal Attention

To mitigate risks, physicians patients should be rescreened at each point of treatment for symptoms like edema, weight gain, or elevated jugular pressure.2 It is recommended that clinicians consider the value of obtaining baseline cardiac imaging before initiating new treatment, taking into account existing risk factors and the particular treatment plan recommended for that patient.12

The cardiac risks in patients in the post cancer treatment phase appear to have similar monitoring needs as any other patient in managing: blood sugar; blood pressure, serum cholesterol, and body weight, and adopting beneficial lifestyle behaviors (not smoking, heart-healthy eating, regular exercise).13-18

For women, it appears that maintaining good psychosocial health may also play a significant role in reducing their risk of cardiovascular dysfunction.19

Regardless of your patients present clinical profile, the need for each of them to know their own risk of heart disease remains a major key to their ongoing care. Data suggest women still do not view heart disease as condition of personal concern, and too few know that hypertension and blood lipid levels have a direct reflection on their heart health.20

As has been said before, cardiac rehabilitation education would benefit any and all patients who have had a cardiac event, yet women and minorities are less frequently referred. Home-based programs benefitted individuals with cancer to lessen their calculated risk for cardiac events by assuring participation in the intervention in a manner that addressed a key barrier to care: ease of access.21

In addition, daily physical activity should be encouraged in patients who are undergoing cancer treatment as well as those in post-treatment, given its proven efficacy in reducing cardiovascular risks and improving overall wellbeing.19

Stay Proactive While Guidelines Evolve

The fact remains, patients who are in cancer treatment remain at increased risk of heart disease, said Dr. Floyd. “While I wouldn’t call it earth shattering or practice changing, there is a need for practitioners to remain attentive, so everyone knows about their heart disease risk.”

As yet, there are no guidelines or good algorithms related to this topic, he said. “But information like this prompts development in the field of cardio-oncology, and that wasn’t a thing as recently as a decade ago.”

Increased awareness of the lingering cardiovascular risks in cancer patients has led to the initiation of a task force at the National Cancer Institute, Dr. Floyd said, and that has prompted clinical trials that may hasten improvements in treatment, prevention, and best practices with regard to the growing number of patients living with cancer.

One such clinical trial—evaluating carvedilol to reduce the cardiovascular risks in women taking TrAstuzumab (Carvedilol) for breast cancer (TACTIC)—for which Dr. Floyd is a study investigator. “From that [work], we hope to find a way to ameliorate the heart disease-related risks while keeping the women on life-prolonging and life-saving medications for a longer period of time.”   

“If the research pans out, prescribing adjuvant beta blockers will roll out to women with earlier stage cancer,” said Dr. Floyd. They are also looking at patient-specific imaging, blood and patient history for biomarkers that could help “build a predictive model of who is at risk before, during and after treatment, and who needs extra versus less monitoring for cardiovascular complications,” he told EndocrineWeb. “We are in desperate need of that.”

“Research on some of the older drugs—like transtuzumab, and those used in childhood cancers—is strong,” Dr. Floyd said, “but the newer drugs, such as the oral tyrosine kinase inhibitors, don’t have the same depth of knowledge.

For example, a common side effect of drug therapies used to treat thyroid cancer is decreased left ventricular function and increased blood pressure but they are so new, we don’t yet know the long term consequences.”

Attending to Cardiac Concerns Should Continue Despite Limited Data

Least understood is the cardiovascular effect of immunotherapy, he said. “That’s revolutionizing cancer care and we have seen some serious cardiac events arising in these patients. We have very little knowledge about who is at risk, how to screen for it, and how to prevent it. That’s the type of medicine that is currently under exploration in oncology.”

While most oncologists are aware of the information in the review, said Eiman Jahangir, MD, MPH, FACC, FAHA, an assistant professor of medicine in the cardio-oncology program at Vanderbilt University Medical Center in Nashville, Tennessee, he agreed that the information on the more targeted therapies is still relatively unknown.

“We are talking about what happens after cancer treatment is completed now because we are seeing survivors die of cardiac events,” Dr. Jahangir told EndocrineWeb. “We are better at helping people live longer with cancer and that’s going to continue to increase,” so we need to get a better handle on lowering CVD risk in these patients.

While the practice of monitoring heart health in certain patients such as those receiving tratsuzumab, which requires ultrasound exams for three months is accepted practice, Dr. Jahangir said, the knowledge is not consistently implemented for all patients.

“We have known about this with breast cancer patients for 20-30 years, yet the lack of focus on reducing CVD risk in patients treated for cancer with these newer drugs is surprising.”

Dr. Jahangir said: Endocrinologists and primary care practitioners have an essential role to play in helping to mitigate the risk factors in patients in the post-cancer treatment stage such as managing diabetes, reducing cholesterol, maintaining a healthy weight, watching alcohol intake.

He would like to see physicians of all stripes make use of the website, an online site focused on the management of cardiac dysfunction as relates to cancer treatment, including information on the particular drugs, cancer type, and even a risk calculator. There is also information clinicians can share with their patients, he said.

Since cardiovascular events may rise following cancer treatment is most likely news to most patients, Dr. Floyd said. “They should be made aware that their risk of experiencing cardiac events and dying from cardiovascular disease is even higher than from their cancer, especially women, including those treated for early stage breast cancer years ago. We need to emphasize heart health and not just cancer screening and follow-up after treatment.”

Continue Reading:
Age, Stage Influence Survival Outcomes in Thyroid Cancer
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