BREAST CANCER AND HEART DISEASE

Breast Cancer and Heart Disease: Understanding the Link

Breast cancer treatment has dramatically improved outcomes for patients, yet it also poses significant long-term health considerations, particularly cardiovascular implications. Understanding the intricate relationship between breast cancer treatments and cardiovascular disease (CVD) is crucial for optimising patient care and survivorship.

Cardiovascular disease (CVD) encompasses a range of conditions affecting the heart and blood vessels. In Australia in 2022, an estimated 1.3 million Australians aged 18 and over (6.7% of the adult population) were living with one or more conditions related to heart, stroke and vascular disease, based on self-reported data from the Australian Bureau of Statistics (ABS) 2022 National Health Survey. This includes 600,000 adults (3.0%) who reported having coronary heart disease (including angina and heart attack).

Can Breast Cancer Affect Your Heart

Women diagnosed with breast cancer have a higher risk of developing cardiovascular complications, such as heart failure, heart attacks, and hypertension. There are several factors that contribute to this:

• Treatment Effects: Some treatments for breast cancer, such as certain chemotherapy drugs and radiation therapy, can have adverse effects on the heart and blood vessels. This is known as cardiotoxicity – damage or dysfunction of the heart muscle caused by medications or treatments. Recognising the signs of cardiotoxicity is crucial for early intervention and management. Symptoms may include shortness of breath, chest pain or discomfort, fatigue, swelling and irregular heartbeat.
• Shared Risk Factors: Breast cancer and cardiovascular disease share common risk factors, including obesity, smoking, physical inactivity and poor diet. Addressing these risk factors through lifestyle modifications can reduce the risk of both diseases.
• Hormonal Factors: Estrogen, a hormone that plays a key role in breast cancer development, may also affect the cardiovascular system. Women who undergo hormonal therapy for breast cancer may experience changes in their cholesterol levels and blood pressure, which can contribute to cardiovascular complications.

Cardiotoxicity

Cardiotoxicity refers to cancer treatment-related damage to the heart muscle (which in some circumstances can be reversed). Cardiomyopathy is a broader term for disease of the heart muscle that can be caused by cardiotoxic treatments as well as other diseases (such as ischaemic heart disease).

In cardiomyopathy, there is a structural change to the heart muscle, which is usually permanent, that affects its ability to pump blood effectively. In severe cases cancer treatment can cause heart failure (a condition where the heart muscle is unable to pump blood efficiently enough to meet the body’s needs) or patient death.

There has been significant improvement in cancer patients’ outcomes over time. In Australia, there is currently a 70% chance of surviving at least 5 years after a cancer diagnosis. However, whilst living longer because of improved cancer care, cancer patients are increasingly developing CVD due to complications of their cancer treatments. Cancer survivors have up to an 8-fold increased risk of developing CVD, and up to 25% of cancer survivors die from CVD that develops within 7 years of their cancer diagnosis, making it the leading cause of death in cancer survivors.

Chemotherapy-Induced Cardiotoxicity

The two main classes of breast cancer treatments that cause cardiotoxicity are anthracycline chemotherapy and targeted therapies. Anthracyclines, such as doxorubicin and epirubicin, can cause dose-dependent damage to the heart muscle via the generation of free radicals and oxidative stress. Targeted therapies including HER2 inhibitors, such as trastuzumab, can also affect the heart by interfering with signalling pathways preventing the heart from functioning normally.

Patient and treatment factors can increase the risk of cardiotoxicity. Patient factors such as age, obesity, hypertension, diabetes and pre-existing CVD can increase a patient’s risk. Treatment factors include the cumulative dosage of certain drugs, and particular treatment combinations (whether this be the combination of specific drugs, or certain drugs in combination with other treatments such as radiotherapy).

Radiation-Induced Cardiotoxicity

Radiation can cause cardiotoxicity primarily due to its impact on the heart tissue and the blood vessels that supply it. This can include:

• Direct Damage to Heart Tissue: High doses of radiation can damage the heart muscle directly. This damage can impair the heart’s ability to contract properly, leading to decreased cardiac function.
• Inflammation: Radiation can trigger an inflammatory response in the heart. This inflammation can cause damage to the cardiac cells and tissues, potentially leading to fibrosis (scarring) and reduced heart function.
• Vascular Damage: Radiation can cause fibrosis and damage to the coronary arteries and other blood vessels. This damage can lead to reduced blood flow to the heart muscle, increasing the risk of insufficient blood supply and heart attacks.
• Altered Cardiac Function: Over time, the effects of radiation-induced damage can alter the normal function of the heart, leading to conditions such as heart failure, arrhythmias (irregular heartbeats), or other forms of cardiac dysfunction.

The overall effect of radiation damage to the heart and blood vessels can increase the risk of developing cardiovascular diseases later in life. This is particularly a concern for individuals who have received radiation therapy for cancer treatment.

These effects can vary depending on the dose of radiation, the duration of exposure, and the specific area of the body that was irradiated. The risk of cardiotoxicity is higher with higher doses of radiation and with treatments that involve radiation to the chest area

It is also important to note that the radiation doesn’t travel very far from the treatment area. So it is usually safe to be with other people. However, as a precaution you will need to avoid very close contact with children and pregnant women for some time. Your treatment team will give you specific advice about this. If you have any concerns about your personal medical treatment, we recommend discussing these with your treating team or GP.

Monitoring and Management

Cardiovascular complications can often display as fatigue, shortness of breath, decreased exercise tolerance, chest pain, palpitations, lightheadedness, headache, swelling or sudden weight gain.

Most side effects of cancer treatment show up in the first 12 months after treatment. Patients are encouraged to report any new or persistent symptoms to their healthcare team for comprehensive assessment and management.

Cardiovascular monitoring before, during and after breast cancer treatment can help detect cardiovascular complications early. This can include assessments of cardiac function through echocardiograms, and use of blood tests to identify early signs of cardiotoxicity. Treatment strategies may include drug adjustments, lifestyle modifications, and cardiac rehabilitation programs.

Unfortunately, despite identification and treatment, some cardiovascular complications of cancer treatment can be permanent, so ensuring patients are aware of potential cardiovascular complications of their cancer treatment allows them to be involved in their cardiovascular health monitoring and treatment.

Long-term survivorship care of breast cancer patients should include tailored strategies to reduce any cardiovascular risks. Lifestyle modifications, including smoking cessation, adoption of a heart-healthy diet, regular physical activity, and stress management play pivotal roles in promoting cardiovascular health post-treatment. Support groups and survivorship programs offer valuable resources and emotional support throughout the recovery journey.

Preventative Strategies

Unfortunately, there is no way to directly prevent cardiotoxicity, however there are steps you can take which may reduce your likelihood of cardiovascular risk, including:

• Controlling blood pressure
• Lowering cholesterol
• Maintaining a healthy blood glucose level
• Consuming a healthy diet
• Not smoking
• Engaging in moderate aerobic exercise

It’s important to discuss the potential health risks and benefits of treatments with your provider if you’ve been diagnosed with cancer. Undergoing frequent heart imaging throughout your cancer treatment may increase your chances of diagnosing cardiotoxicity in its early stages.

Learn More About Breast Cancer and Heart Disease in Our Online Q&A

In our recent Q&A event, moderated by Author and Journalist, Annabel Crabb, our panel of experts explored the topic of breast cancer and heart health; the nature, prevalence and management of cardiotoxicity and cardiovascular disease after breast cancer; strategies for prevention; a multidisciplinary team approach to risk management including the role of GP’s and cardiologists; and self-management strategies to reduce cardiovascular risk.

We also heard a patient’s perspective on the long-term impact that breast cancer treatment had on her heart.

Get Support

The relationship between breast cancer and heart health underscores the importance of comprehensive care for breast cancer patients. By better understanding this connection, health professionals and patients can take proactive steps to mitigate risk factors and monitor cardiac health, and individuals can optimize their long-term health outcomes and quality of life.

Supporting someone going through cardiotoxicity involves both practical and emotional support. Here are some ways to offer meaningful help:

Practical Support

• Medical Appointments: Help them keep track of medical appointments and treatment schedules. Offer to accompany them to appointments if they’d like.
• Medication Management: Assist with organising medications, keeping track of doses, and ensuring they take their medications as prescribed.
• Monitoring Symptoms: Help them monitor and document symptoms such as shortness of breath, swelling, or fatigue. This can be useful for healthcare providers.
• Diet and Lifestyle: Encourage and help them maintain a heart-healthy diet and lifestyle. This might include preparing nutritious meals or helping with exercise routines that are approved by their healthcare provider.
• Emergency Preparedness: Ensure they have a plan for emergencies, including knowing when to seek immediate medical help if symptoms worsen.

Emotional Support

• Listen and Validate: Be a compassionate listener. Acknowledge their feelings and concerns without judgment.
• Encourage Open Communication: Support them in discussing their condition with their healthcare team and asking questions about their treatment and prognosis.
• Provide Reassurance: Offer reassurance and encouragement. Remind them that their healthcare team is there to help and that treatment plans are designed to manage and mitigate risks.
• Create a Supportive Environment: Help create a calm and supportive environment at home. This could involve managing stressors and providing a comforting presence.
• Encourage Social Interaction: Encourage them to stay connected with friends and family, as social support can be very beneficial for mental and emotional well-being.
• Educate Yourself: Learn about cardiotoxicity and its management so you can better understand what they are going through and how to offer relevant support.

Professional Support

• Counseling and Therapy: Encourage them to seek counseling or therapy if they are struggling emotionally. Professional support can be crucial in managing the psychological impact of dealing with a chronic condition.
• Support Groups: Help them find and connect with support groups for individuals dealing with cardiotoxicity or similar health issues. Sharing experiences with others who understand their situation can be very comforting.
• Healthcare Coordination: Assist in coordinating care among their various healthcare providers to ensure they are receiving comprehensive and cohesive treatment.

FAQs

Can Breast Cancer Cause High Blood Pressure?

Breast cancer and high blood pressure (hypertension) are not directly related. However, several factors related to breast cancer and its treatment can contribute to elevated blood pressure:

• Cancer Treatments: including chemotherapy, hormone therapy and targeted therapies.
• Medication Side Effects: steroids used to manage side effects of cancer treatments or to treat inflammation can lead to higher blood pressure.
• Stress and Anxiety: the stress and anxiety associated with a cancer diagnosis and treatment can contribute to elevated blood pressure. Chronic stress can impact cardiovascular health and increase hypertension risk.
• Underlying Health Conditions: individuals with pre-existing conditions like pre-hypertension or heart disease may experience worsening of these conditions due to cancer treatments or stress.

Can Radiation for Breast Cancer Cause High Blood Pressure?

Radiation therapy for breast cancer is not commonly known to directly cause high blood pressure (hypertension). However, several indirect factors related to radiation therapy and its impact on the body can contribute to elevated blood pressure:

• Impact on Heart: radiation to the chest area can cause damage to the heart and blood vessels. This damage can lead to increased risk of cardiovascular diseases, including hypertension.
• Inflammation: radiation can induce an inflammatory response, which might affect the cardiovascular system and contribute to hypertension.
• Secondary Effects: during and after treatment, patients might have changes in their lifestyle, such as reduced physical activity or dietary changes, which could affect blood pressure.
• Medication Interactions: while radiation itself is less likely to cause high blood pressure directly, some medications used in combination with radiation therapy might influence blood pressure.

Can Breast Cancer Cause Heart Palpitations?

Anxiety, depression, sleep disturbance, fatigue, cognitive dysfunction, and pain are common symptoms reported by patients with breast cancer. Recent evidence published in the European Journal of Oncology Nursing, suggests that palpitations, a feeling of the heart racing or pounding, may be equally common for breast cancer patients.

If you have heart palpitations with severe shortness of breath, chest pain or fainting, seek emergency medical attention. If your palpitations are brief and there are no other concerning signs or symptoms, make an appointment to see your healthcare provider.

Can Breast Cancer Cause Chest Pain?

Secondary breast cancer means that a cancer that began in the breast has spread to another part of the body. It is also called advanced or metastatic breast cancer.

The symptoms you have depend on where the cancer has spread to. The symptoms listed here can also be caused by other medical conditions so might not be a sign that the cancer has spread, however, you may have any of these symptoms if your cancer has spread into the lungs:

• a cough that doesn’t go away
• shortness of breath
• ongoing chest infections
• chest pain
• coughing up blood
• a buildup of fluid between the chest wall and the lung

It is important that if you experience chest pain and breast cancer, or any of the above symptoms throughout your breast cancer treatment you discuss these with your treatment team.

Improving Cardiovascular Care

There are many ways to improve the cardiovascular care, and hence outcomes and quality of life of breast cancer patients. This includes:

• Baseline cardiovascular assessments of cancer patients and consideration of this risk in cancer treatment recommendations
• Proactive monitoring of cancer patients to detect cardiovascular complications of cancer treatments early
• Multidisciplinary care between oncologists, cardiologists and general practitioners to manage cardiovascular risk and any established cardiovascular disease
• Increased research into occurrence and treatment of cardiovascular complications of cancer treatments