Serious heart problems, including ventricular dysfunction and congestive heart failure, have been reported as side effects in a small number of breast cancer patients receiving Herceptin (generic name, trastuzumab) alone or in combination with chemotherapy.
An estimated10% of patients taking Herceptin have experienced significant decreases in heart function. Furthermore, 1.7% to 4.1% of patients taking Herceptin have experienced heart failure.[1]
In the past, cardiac side effects were observed in patients receiving Herceptin either after chemotherapy with an anthracycline (such as doxorubicin) or in combination with an anthracycline drug. Typical courses of a combination of Herceptin and an anthracycline drug are administered during a period of 1 to 2 years. The anthracycline class of chemotherapeutic drugs is known to have potential cardiac side effects.
Heart failure is more common among breast cancer patients who receive Herceptin in combination with the AC chemotherapy regimen; i.e., chemotherapy consisting of an anthracycline, such as Adriamycin (doxorubicin) or Ellence, and cyclophosphamide). However, Herceptin is not approved for use with the AC chemotherapy combination outside of a clinical trial setting.
A recent small study of Herceptin therapy given before exposure to any other potentially cardiotoxic treatments shows that 9 weeks of a combination of Herceptin therapy and chemotherapy was effective treatment for breast cancer and did not result in cardiac failure in any of the 116 patients treated.[1, 2] Moreover, the patients treated with Herceptin and chemotherapy exhibited fewer reductions in heart function than did patients treated with chemotherapy alone. However, the shorter course of Herceptin therapy has not been approved by regulatory agencies.
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.
REFERENCES
1. B. Robinson. NCI Cancer Bulletin. New trastuzumab regimen lessens cardiac side effects. 2006; 3(9):1-2.
2. H. Joensuu et al. New England Journal of Medicine. 02/23/06.
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