In a small number of women with breast cancer, the use of Herceptin alone or in combination with chemotherapy can lead to serious heart problems, including ventricular dysfunction and congestive heart failure.
Heart failure is more common among breast cancer patients who receive Herceptin in combination with the AC chemotherapy regimen (chemotherapy consisting of an anthracycline, such as Adriamycin or Ellence, and cyclophosphamide). However, Herceptin is not approved for use with the AC chemotherapy combination outside of a clinical trial setting.
Women considering Herceptin as treatment for breast cancer should have their heart function evaluated by a doctor before beginning treatment. Once on Herceptin, women should be closely monitored by their doctor for any heart problems that may occur.