Breast Cancer Patients
Breast cancer is the most common invasive cancer diagnosed in women. Of every 8 women, 1 woman is diagnosed with breast cancer in her lifetime. In 2017, more than 250,000 new cases of breast cancer are diagnosed in the United States and more than 40,000 women are expected to die in the United States from breast cancer in 2017. Despite these numbers, death rom breast cancer has been declining over the past 2 decades due to improvement of diagnosing as well as treating breast cancer. Today, there are over 3,000,000 breast cancer survivors. Women who survive breast cancer may face many health challenges, but the number 1 cause of death in breast cancer survivors (and, in fact, all women) remains heart disease. Although new breast cancer therapies and radiation therapy have increased survival in many women with breast cancer, they may also increase the risk of subsequent heart problems. In the vast majority of patients, the benefits of these treatments substantially outweigh this risk.
Breast cancer treatments include the following:
- Chemotherapy involves drugs that are intended to kill the cancer cells or stop them from dividing. In many cases, chemotherapy includes a class of chemotherapies called anthracyclines.
- Surgery involves removal of the breast tumor. How much of the breast is removed depends on the size of the tumor and location of tumor and other factors.
- Radiation uses high-energy radioactive beams and often accompanies surgery to lower the chance cancer will recur in the breast or nearby lymph nodes.
- Targeted therapies target specific receptors that are highly expressed on cancer cells. For instance, some breast cancer types have a receptor called HER2. As a result, novel therapies have been developed that target HER2. One such example is trastuzumab (Herceptin).
- Breast cancer treatments are often used in combination to provide the highest chance for a cure.
Although these therapies have increased the survival of cancer patients, some may cause cardiotoxicity or damage to the heart. Cardiotoxicity can occur in various forms and can include damage to the heart muscle itself, the heart arteries, or the heart valves. If the heart muscle is damaged, the heart will pump less efficiently—a disease called cardiomyopathy, or heart failure. Some chemotherapy (such as anthracyclines) as well as targeted therapies (such as trastuzumab) can cause heart failure in women. In addition, coronary artery disease (CAD), where the heart muscle may not receive an adequate amount of blood to function well can occur because of the blockages in the arteries. CAD is the main reason for heart attacks, which occur when the blood flow suddenly is completely obstructed to a section of the heart muscle, causing the heart muscle to stop functioning properly. CAD is the number 1 killer of men and women in the world. With respect to breast cancer, radiation therapy may increase he risk of CAD in breast cancer survivors. What is interesting is that radiation increases the risk of CAD years (over event decades) after completion of therapy.
For these reasons, all breast cancer patients and breast cancer survivors should be cognizant of heart disease risk and should discuss these risks with their doctors. In particular, prevention of heart disease is the best strategy. After breast cancer treatment and during survivorship, patients and their physicians have an opportunity to take important prevention steps to decrease the risk of a subsequent heart attack. Specifically, the ABCDE schematic for cancer survivors apply particularly to breast cancer patient and breast cancer survivors.