Breast Cancer Treatment May Cause Heart Damage

Approximately 20 percent of women who develop early breast cancer have HER2-positive (human epidermal growth factor receptor-2-positive) tumors. If left untreated, these tumors generally have a worse prognosis than HER2-negative tumors. The case is the same with advanced breast cancer as well.

Currently, the standard treatment for HER2-positive breast cancer is chemotherapy with trastuzumab given in combination with one of several chemotherapy regimens.

Recent research published in the Cochrane Database of systematic reviews, however, reported increased risk of heart damage such as congestive heart failure and LVEF (Left Ventricular Ejection Fraction) decline with trastuzumab in HER2-positive tumors. The study had reviewed 7 trials involving 1497 patients with metastatic breast cancer undergoing breast cancer treatment.

Similarly, researchers at the University of Louisville, Kentucky and Kentucky One Health too found that the heart in some patients ‘seemed to be weakening under treatment’.

‘Breast cancer patients treated with either trastuzumab or lapatanib may have an increase in stress hormones (catecholamines), a decrease in protective growth factor (neuregulin), and an increase in blood pressure. This may contribute to why certain patients have a decline in heart function during chemotherapy treatment,’ said Dr. Carrie Geisberg Lenneman, the lead author of the study.

Now we know the ‘why’ of the problem, but how to deal with the problem?

‘Shorter duration of therapy may reduce cardiotoxicity and maintain efficacy,’ suggested researchers at University of Milan, Italy. But they could not definitely conclude this as the evidence was insufficient due to small numbers of patients in the trials they reviewed.

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Breast cancer treatment

So, what does breast cancer treatment actually involve? Today there are multiple treatment choices for every stage of breast cancer. Your doctor will be the right person to guide you regarding the best treatment options for you. But do get a second opinion about your diagnosis and treatment plan even though it may feel overwhelming. A slight delay in starting treatment generally would not pose a risk. Talk to your doctor about it. Even if you have started treatment, it is not too late to get a second opinion.

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Let’s check out the treatment options available.

Surgery: Surgery is considered to be the first line of treatment for breast cancer. Your options are

• Lumpectomy or breast conserving surgery where only the tumor and a small amount of surrounding tissue is removed.

• Mastectomy where all of the breast tissue is removed.

• Lymph node removal when cancer spreads beyond the breast. This is done along with lumpectomy or mastectomy.

• Cryotherapy to kill the tumor cells by freezing them. It is still in experimental stage.

• Other surgeries include preventive surgery of the breast and ovary and reconstruction surgery of the breast after mastectomy.

Chemotherapy: Chemotherapy is the treatment that uses drugs to destroy cancer cells in the body.

Radiotherapy: Radiotherapy is the treatment that uses high-energy radiation to effectively destroy cancer cells. Radiation therapy reduces your chances of breast cancer recurrence by about 70 percent.

Hormone therapy: Hormone therapy is used in people with hormone-receptor-positive breast cancers. The therapy works by lowering the estrogen levels in the body and by blocking the action of estrogen on cancer cells.

Targeted therapy: Targeted therapies use drugs that interfere with specific molecules involved in the cancer cell growth, for example, drugs that interfere with tumor blood vessel development, or drugs that stimulate the immune system to destroy cancer cells. Trastuzumab (Herceptin) is the drug used in the targeted therapy for HER2-positive breast cancers. It destroys the specific proteins that are present in the cancer cells but not in the normal cells.

Acupuncture, meditation, yoga, are some therapies that are used along with conventional medicines to improve quality of life, treat side effects of treatment, and to relieve symptoms.

Heart damage symptoms

Although not everyone undergoing breast cancer treatment will run the risk of getting heart disease, chemotherapy, radiation therapy, and hormonal therapies do increase the risk of heart damage. For example, chances of cardiomyopathy (weakening of the heart muscle) increase with chemotherapy for HER2-positive breast cancers.

Certain types of chemotherapies may cause a heart attack or arrhythmias. Arrhythmias generally occur during the administration of the drug, so if you feel lightheaded or dizzy, tell your chemo doctor.

Targeted therapies with angiogenesis inhibitors are known to increase blood pressure (hypertension). Radiation therapy, on the other hand, increases the risk of cardiomyopathy, coronary artery disease, and heart attack.

You may be having heart problems if you have the symptoms that include –

• Rapid or irregular heart beat
• Shortness of breath
• Palpitations
• Swelling in the feet and lower leg
• Fatigue, weakness, dizziness
• Coughing
• Need to urinate at night
• Loss of appetite

Inform your doctor as soon as you get these symptoms, irrespective of whether the symptoms occur during the treatment or after the treatment.

References:

1. Lenneman, C., Abdallah, W., Smith, H., Abramson, V., Mayer, I., Silversteina, C., Means-Powell, J., Paranjape, S., Lenihan, D., Sawyer, D. and Raj, S. (2014).Sympathetic Nervous System Alterations with HER2 Antagonism: An Early Marker of Cardiac Dysfunction with Breast Cancer Treatment?. ecancermedicalscience
2. http://www.ncbi.nlm.nih.gov/pubmed/24919460
3. http://www.ncbi.nlm.nih.gov/pubmed/22513938
4. http://www.breastcancer.org/treatment



Source-Medindia