Protecting Your Heart While Fighting Breast Cancer: What Every Woman Should Know This October
October is Breast Cancer Awareness Month, and while we focus on pink ribbons and early detection, there's another conversation we need to have. If you or someone you love is facing breast cancer treatment, understanding how these therapies can affect your heart might be one of the most important discussions you'll have with your medical team.
Why Your Cardiologist Cares About Your Cancer Treatment
I've spent years caring for hearts in San Diego, and increasingly, I'm sitting down with women who've beaten breast cancer but are now dealing with heart problems they never expected. The truth is, many of the same treatments that save lives from cancer can put stress on your heart. As a cardiologist, I want you to know about this connection before you start treatment, so we can protect both your life and your heart health.
When we talk about breast cancer treatment, we're often discussing powerful medications like doxorubicin (an anthracycline chemotherapy) and trastuzumab (Herceptin), along with radiation therapy. These treatments work remarkably well against cancer cells. However, they can also affect the heart muscle in ways that may not show up right away.
Understanding Cancer Therapy-Related Heart Problems
The medical term is "cardiotoxicity," but what does that really mean for you? Think of your heart as a muscle that needs to contract and relax millions of times each day. Some cancer treatments can weaken this muscle, making it less efficient at pumping blood throughout your body. This can happen during treatment or sometimes years later.
Anthracycline chemotherapy drugs carry a low but real risk of weakening the heart muscle (cardiomyopathy). The risk increases with higher cumulative doses. Trastuzumab, which targets HER2-positive breast cancers, can cause cardiac dysfunction, especially when given with or after anthracyclines. Radiation therapy to the left breast can affect nearby cardiac structures, potentially leading to coronary artery disease, valve problems, or pericardial complications down the road. Aromatase inhibitors, commonly used for hormone receptor-positive cancers, may increase your risk of heart disease and stroke. Newer medications like CDK 4/6 inhibitors can occasionally cause heart rhythm abnormalities.
Research shows that up to 16% of younger women (under 65) who receive anthracyclines or trastuzumab develop some form of cardiovascular disease within 10 years of treatment. That's a significant number, and it's why we need to be proactive.
What Happens to Your Heart During Treatment
Your heart is under stress during cancer therapy. While your ejection fraction (the percentage of blood your heart pumps out with each beat) might look normal on tests, subtle changes can be happening at the cellular level. This is where modern cardiology has made real advances.
We now have a technique called global longitudinal strain (GLS) imaging. Think of it as a more sensitive way to measure how well your heart muscle is contracting. Regular echocardiograms measure your ejection fraction, which is useful, but GLS can detect problems earlier, often before your ejection fraction drops. This early warning system allows us to intervene before permanent damage occurs.
When GLS drops by 12 to 15% from your baseline measurement during cancer treatment, even if your ejection fraction looks fine, we know your heart muscle is under strain. This is our signal to act.
The Monitoring Plan You Should Expect
If you're starting treatment with anthracyclines, trastuzumab, or left-sided radiation, here's what monitoring typically looks like:
Before you start treatment, you should have a baseline echocardiogram with GLS measurement. This gives us your personal starting point. If you're receiving trastuzumab, expect repeat echocardiograms every three months during treatment. For anthracycline therapy, we typically check your heart function at the end of treatment and again six months later. If you're getting high-dose anthracyclines (over 240 mg/m²), we monitor more frequently.
After treatment ends, annual check-ins are important, with imaging reserved for those who have symptoms or high-risk features. Late-onset heart problems can show up years later, so staying connected with your healthcare team matters.
Your oncologist and cardiologist should be working together on this. If you're being treated for breast cancer and nobody has mentioned cardiac monitoring, bring it up. You deserve a coordinated care plan that addresses both your cancer and your heart.
When We Need to Protect Your Heart
Sometimes during treatment, your GLS will show that early warning sign we talked about. When this happens, we don't just watch and wait. We start medications that protect your heart muscle.
Two classes of medications have proven effective: ACE inhibitors (like ramipril or enalapril) and beta-blockers (like bisoprolol or carvedilol). These medications actively protect your heart muscle from further injury while you continue cancer treatment.
The SUCCOUR-MRI trial showed something important. When doctors started heart-protective medications in women whose GLS had declined (even though their ejection fraction was still normal), those women had better heart function a year later compared to women who didn't get early intervention. The key word here is "early." We're catching problems before they become permanent.
Research suggests bisoprolol may offer slightly better protection for GLS preservation compared to ramipril, though both medications help. I often consider your other health conditions when choosing which medication to start. If you have asthma, a beta-blocker might not be ideal. If you have certain kidney conditions, we might lean toward a beta-blocker instead of an ACE inhibitor.
Here's something really important: these heart medications don't interfere with your cancer treatment. They don't make chemotherapy less effective or increase cancer recurrence. This was a concern early on, but multiple studies have confirmed that protecting your heart doesn't compromise your cancer outcomes.
Risk Factors That Matter
Not everyone has the same risk of developing heart problems from cancer treatment. Certain factors increase your risk:
If you already have high blood pressure, diabetes, or existing heart disease, your risk is higher. Age plays a role. Both younger women (under 50) and older women (over 65) face increased risk. Previous exposure to anthracyclines or radiation increases risk with additional cardiotoxic therapies. Smoking significantly increases your cardiovascular risk. Being overweight or obese compounds the risk. A family history of early heart disease is relevant.
If several of these apply to you, having a consultation with a cardiologist before starting cancer treatment is wise. We can optimize your blood pressure, cholesterol, and blood sugar control before you begin, giving your heart the best possible foundation.
What You Can Do Right Now
You're not powerless here. While you're going through treatment, and after, there are concrete steps that help protect your heart:
Stay physically active within the limits your oncologist sets. Even light walking helps maintain cardiovascular fitness. Don't smoke, and if you do, this is an excellent time to quit. Ask your oncology team about smoking cessation resources. Eat a heart-healthy diet rich in fruits, vegetables, whole grains, and lean proteins. Limit processed foods and excess salt. Manage your blood pressure and blood sugar if you have diabetes or pre-diabetes. Take any prescribed heart medications consistently. Keep your cholesterol in check. Watch for symptoms like unusual shortness of breath, persistent fatigue that's different from chemo fatigue, swelling in your legs or feet, or chest discomfort. Report these to your doctor right away.
Weight gain is common during breast cancer treatment, particularly with certain hormonal therapies. This isn't about appearance. Excess weight increases your cardiovascular risk. If you're gaining weight, talk to your team about nutrition counseling and safe exercise programs.
Looking at Long-Term Heart Health
Finishing cancer treatment is a major milestone worth celebrating. You've been through so much. However, your heart still needs attention in the years ahead.
Some heart problems from cancer treatment don't show up until 5, 10, or even 15 years later, especially if you received both anthracyclines and chest radiation. This delayed cardiotoxicity is why annual check-ups that include cardiovascular assessment are important for all breast cancer survivors.
If you received anthracyclines, trastuzumab, or left chest radiation, I recommend staying connected with a primary care provider who knows your treatment history. They should be checking your blood pressure, cholesterol, and blood sugar annually. If you develop new symptoms like shortness of breath with activities you used to do easily, leg swelling, or unusual fatigue, don't dismiss them as just getting older. These could be signs your heart needs attention.
Some women benefit from periodic echocardiograms even without symptoms, particularly if they received high-dose anthracyclines or combination cardiotoxic therapies. This is a conversation worth having with your doctor about three to five years after treatment ends.
When Your Ejection Fraction Drops
Sometimes despite our best efforts at prevention, the heart's pumping function decreases. If your ejection fraction falls below 53%, or drops more than 10 percentage points from your baseline, we diagnose cancer therapy-related cardiac dysfunction.
Many women respond well to heart failure medications. The same medications we use for prevention (ACE inhibitors and beta-blockers) are also treatments. Sometimes we add other medications like aldosterone antagonists or newer agents called SGLT2 inhibitors.
The sooner we catch and treat this, the better the outcome. I've had patients whose heart function improved significantly with medication, allowing them to live full, active lives. Some even saw their ejection fraction return to normal range.
If your heart function declines significantly during cancer treatment, your oncologist might need to modify your regimen. Perhaps switching medications, reducing doses, or temporarily pausing treatment. This is a team decision involving you, your oncologist, and your cardiologist. The goal is always to cure your cancer while preserving your quality of life.
Special Considerations for Different Treatments
Let me address some specific treatment scenarios:
If you're receiving trastuzumab for metastatic breast cancer, you might be on this medication indefinitely. Long-term trastuzumab requires continued cardiac monitoring, though we can often space out echocardiograms once we establish a stable pattern. The interval depends on your individual risk factors and how your heart has tolerated treatment so far.
For women receiving radiation therapy to the left breast, the risk to your heart depends on the radiation dose to cardiac structures and your other cardiovascular risk factors. Modern radiation techniques have reduced cardiac exposure significantly compared to older methods, but some risk remains. If you're getting radiation, ask about cardiac-sparing techniques.
Hormone therapy with aromatase inhibitors can cause joint pain and affect your cholesterol levels. While these medications are generally well tolerated, they do slightly increase cardiovascular risk, particularly for heart attacks and strokes. This is another reason to aggressively manage your blood pressure, cholesterol, and lifestyle factors while on these medications.
The Emotional Side of Dual Risks
Finding out you have breast cancer is terrifying enough. Then learning that the treatment might affect your heart adds another layer of worry. I see this anxiety in my patients regularly, and I want you to know it's completely understandable.
Here's what helps: knowledge and a good care team. Understanding these risks allows you to be an active participant in your care rather than a passive recipient. When you know what's being monitored and why, when you understand what symptoms to watch for, you feel more in control.
Many women tell me they feel caught between two fears: cancer recurrence and heart disease. Some worry that bringing up heart concerns might seem ungrateful for their cancer treatment. Let me be clear: you can appreciate life-saving cancer therapy and still advocate for your heart health. Your care team wants to address both concerns.
If anxiety about heart risks is affecting your quality of life, talk to your oncology team about this. Many cancer centers have psychologists or counselors who specialize in helping patients cope with medical anxiety. There's no shame in needing support. You're dealing with a lot.
Questions to Ask Your Oncology Team
When you meet with your oncologist, consider asking these questions:
Based on my planned treatment regimen, what's my risk of heart problems? Will I have baseline cardiac testing before treatment starts? How often will my heart function be monitored during and after treatment? At what point would you consider referring me to a cardiology specialist? Should I be taking any heart-protective medications during treatment? What symptoms should prompt me to call you right away? Will I need long-term cardiac follow-up after finishing cancer treatment?
Don't worry about asking "too many" questions. This is your health, and understanding your treatment plan is your right. Any oncologist worth their salt welcomes these questions and should have clear answers.
The Future of Cardio-Oncology
This field is evolving rapidly. When I started in cardiology, we didn't have GLS imaging to catch early heart problems. We didn't know that starting heart medications at the first sign of strain could prevent permanent damage. We didn't have the collaborative cardio-oncology clinics that many cancer centers now offer.
Research continues on better ways to prevent cardiotoxicity, more sensitive monitoring techniques, and novel cardioprotective agents. Clinical trials are testing whether medications like SGLT2 inhibitors, originally developed for diabetes and heart failure, might also protect against cancer therapy-related heart damage.
We're also learning more about genetic factors that might predict who's at higher risk for cardiotoxicity. In the future, we may be able to personalize cardiac monitoring and prevention strategies based on your individual genetic profile.
All of this gives me hope that with each passing year, we're getting better at curing cancer while protecting hearts.
Your Survivorship Plan
When you finish active cancer treatment, you should receive a survivorship care plan. This document should outline what cancer treatments you received, what late effects to watch for (including cardiac effects), and what follow-up care you need.
Make sure your survivorship plan addresses your heart. It should specify if and when you need cardiac imaging, what symptoms to watch for, and which provider is responsible for your cardiac follow-up. If your plan doesn't mention your heart and you received cardiotoxic treatments, ask why.
Your primary care doctor needs a copy of this plan. Many PCPs aren't aware of the cardiac risks from cancer treatments, and this documentation helps them provide better care. When you establish care with a new doctor, mention your breast cancer treatment history, even if it was years ago.
Final Thoughts This Awareness Month
This October, as we raise awareness about breast cancer, I want you to also be aware of the connection between cancer treatment and heart health. This isn't meant to scare you. It's meant to empower you.
If you're facing breast cancer treatment, know that with proper monitoring and early intervention when needed, most women get through treatment with their hearts intact. The advances in both oncology and cardiology mean we can cure more cancers while causing less collateral damage to the heart.
If you're a breast cancer survivor, even if your treatment was years ago, mention your treatment history at every doctor visit. Don't assume that because you feel fine, your heart is fine. Get your blood pressure checked. Know your cholesterol numbers. Stay active. These simple things make a real difference.
And if you're supporting someone through breast cancer treatment, help them advocate for cardiac monitoring. Offer to go to appointments and ask questions. Help them watch for worrisome symptoms. Your support matters more than you know.
We've made remarkable progress in treating breast cancer. Survival rates continue to improve. Now we need to make sure survivors live long, healthy lives with strong hearts. That's why this dual awareness matters so much. Cancer health and cardiac health both deserve our attention.
Take care of your heart while fighting cancer. It's possible to do both, and you deserve a care team that helps you with both goals. This October and every month, remember that surviving cancer is just the beginning. Thriving after cancer, with a healthy heart, is the real victory.
Published on damianrasch.com
The above information was composed by Dr. Damian Rasch, drawing on individual insight and bolstered by digital research and writing assistance. The information is for educational purposes only and does not constitute medical advice.
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