A new study provides two reasons to monitor heart function among breast cancer patients receiving two common therapies. The findings are particularly important for women who have other risk factors for heart problems before treatment begins. The study was published in the August 2006 issue of the Journal of Clinical Oncology.
Researchers at M.D. Anderson Cancer Center in Houston found that 28 percent of women with advanced breast cancer who received trastuzumab (Herceptin) for a year or more experienced impaired heart function, but that it could be reversed with medical treatment.
Among the patients who received long-term trastuzumab between 1998 and 2003 and were followed for nearly three years, 15.6 percent had moderate heart damage that did not cause symptoms, and another 10.9 percent developed impaired heart function that caused symptoms such as shortness of breath and fluid retention. One patient died of congestive heart failure.
"Long-term use of Herceptin appears to be safe, but some patients will experience cardiac toxicity. The good news is that this toxicity appears to be reversible with medical treatment such as beta-blockers and ACE inhibitors," explained the authors.
Other findings from this study relate to women who received radiation to the left side of the chest. It turns out that, compared to women who received no radiation at all, more women whose left side was irradiated developed coronary artery disease (25 percent versus 10 percent) or had a heart attack (15 percent versus 5 percent).
Having high blood pressure before therapy increased the risk of heart disease associated with radiation therapy in the left-side group. The good news is that recent advances in radiation techniques allow more accurate monitoring and control of radiation to the tissues of the heart during treatment for left-side breast cancer.
Pay special attention to your heart if you take (or have taken) Herceptin for an extended period of time, or if you received radiation therapy on the left side of your chest. You may want your family doctor to talk with your oncologist about what tests should be done to monitor you after radiation or Herceptin treatment is completed. Report any unusual symptoms, including shortness of breath while climbing stairs, as soon as you experience them.