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.
Herceptin (chemical name: trastuzumab) is a targeted therapy medicine used to treat HER2-positive breast cancer. Heart muscle damage and heart failure are serious possible side effects of Herceptin, especially when Herceptin is given after an anthracycline chemotherapy medicine.
Because many studies have shown a link between being overweight and obese and heart failure in the general population, doctors wanted to know if being overweight or obese increased a woman’s risk of heart problems if she were receiving anthracycline chemotherapy and/or Herceptin to treat breast cancer. Doctors call heart problems caused by chemotherapy “cardiotoxicity.”
A study suggests that being overweight or obese significantly increases the risk that a woman will have heart problems from anthracyclines and/or Herceptin.
The research was published online on July 25, 2016 by the Journal of Clinical Oncology. Read the abstract of “Obesity as a Risk Factor for Anthracyclines and Trastuzumab Cardiotoxicity in Breast Cancer: A Systematic Review and Meta-Analysis.”
This study was a meta-analysis -- a study that combines and analyzes the results of many earlier studies. In this case, the results of 8,745 women from 15 studies were analyzed. All the women were diagnosed with breast cancer and treated with anthracyclines and/or Herceptin. About 91% of the women who were treated with Herceptin also were treated with anthracyclines.
The analysis showed that of the 8,745 women in the study, 17% had heart problems:
- 20% of the women treated with anthracyclines alone had heart problems
- 16% of the women treated with Herceptin, with or without an anthracycline, had heart problems
When the researchers compared the rates of heart problems among healthy weight, overweight, and obese women in the study, they found:
- women at a healthy weight had the lowest risk of developing heart problems
- overweight women had an intermediate risk of developing heart problems
- obese women had the highest risk of developing heart problems
If you’ve been diagnosed with breast cancer and anthracycline chemotherapy and/or Herceptin will be part of your treatment plan, it’s a good idea to ask your doctor about your risk of treatment-related heart damage, especially if you are overweight. You also may want to ask your doctor if 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.