Anthracycline chemotherapy medicines kill cancer cells by damaging their genes and interfering with their reproduction. Adriamycin (chemical name: doxorubicin), Doxil (chemical name: doxorubicin), and Ellence (chemical name: epirubicin) are all anthracyclines. While anthracyclines increase breast cancer survival rates, they can have a toxic effect on the heart. Women who get anthracycline chemotherapy should be tested for heart problems before starting chemotherapy and should be continuously monitored for developing problems during treatment.
Doctors wanted to know if there were certain factors that increased a woman’s risk for heart problems if she were receiving anthracycline chemotherapy to treat breast cancer. Doctors call heart problems caused by chemotherapy “cardiotoxicity.”
A small study has found that older women and women with a higher body mass index (BMI) are more likely to have anthracycline-related heart problems.
The study was published online on July 16, 2015 by the journal The Oncologist. Read the abstract of "Diastolic Dysfunction Following Anthracycline-Based Chemotherapy in Breast Cancer Patients: Incidence and Predictors.”
Diastolic dysfunction means there is a problem with how the heart fills with blood. The heart may fill too slowly or the ventricles (the lower chambers of the heart) may not relax properly, which can lead to extra pressure and fluid in the blood vessels of the lungs or in the blood vessels leading back to the heart.
The study involved 85 women diagnosed with breast cancer who were going to be treated with anthracycline-based chemotherapy. All the women had basic heart function tests before chemotherapy started. Half the women were older than 50 and half were younger; all the women received chemotherapy at the same hospital.
The women received one of three chemotherapy regimens:
- FECX6: 5-fluorouracil (brand name: Adrucil), Ellence, and Cytoxan (chemical name: cyclophosphamide) once every 21 days for a total of six cycles
- ACX4-T: Adriamycin and Cytoxan once every 21 days for a total of four cycles, followed by Taxol (chemical name: paclitaxel) weekly for 12 weeks
- ACX4-TH: Adriamycin and Cytoxan once every 21 days for a total of four cycles, followed by Taxol and Herceptin (chemical name: trastuzumab) every 21 days for 9 months
As soon as the women completed chemotherapy, the researchers did another check of basic heart function. The researchers also checked the women’s heart function 3 months and 9 months after chemotherapy was completed. The women whose regimens included Herceptin, which is known to cause heart problems, had additional heart function tests at 6 months and 12 months after chemotherapy was completed.
The women were followed for 1 year.
At the end of the follow-up year, 49 (57.6%) of the women had developed diastolic dysfunction:
- the problem persisted in 36 women (73%)
- the problem eventually reversed itself in 13 women (27%)
One woman died from heart problems caused by chemotherapy.
Being treated with Herceptin in addition to an anthracycline didn’t make a difference in the likelihood of developing diastolic dysfunction:
- 60% of women treated with an anthracycline and Herceptin developed heart problems
- 57% of women treated with just an anthracycline developed heart problems
Women who were older or had a higher BMI were more likely to develop heart problems than women who were younger or had a lower BMI.
“These findings may help identify patients at higher risk for developing a clinically relevant anthracycline cardiotoxicity from those at lower risk and to differentiate monitoring programs for breast cancer patients according to their risk,” said Jose Serrano, M.D., of the Hospital Universitario de Fuenlabrada, Servicio de Cardiologia, in Madrid, Spain, and the lead author of the study. “Our study is the first to characterize the incidence of diastolic dysfunction in a cohort of numerous patients receiving anthracyclines in a systemic and prospective way. Data on the relationship between biomarkers and diastolic dysfunction are scarce.”
If you’ve been diagnosed with breast cancer and anthracycline chemotherapy will be part of your treatment plan, it’s a good idea to ask your doctor about your risk of treatment-related heart damage and whether or not visiting a cardiologist before treatment starts is a good idea for you. The cardiologist can evaluate your heart function and decide if you’re at high risk for developing heart disease or heart failure from breast cancer treatment. You also may want to ask your oncologist how your heart function will be monitored during treatment.
Together, you can decide on the best treatment plan for your unique situation.