August 16, 2006

TAMPA, Fla.  — A new study supports the need to monitor heart function among breast cancer patients receiving common therapies. The findings are particularly important for women who have other risk factors for heart disease or cardiac dysfunction before treatment begins. The study is published online in the Journal of Clinical Oncology. Dr. Eleanor Harris, lead author, is Clinical Director of Radiation Oncology at H. Lee Moffitt Cancer Center & Research Institute. She performed the study while at the University of Pennsylvania.

Harris and fellow researchers found that women with early stage breast cancer who received radiation therapy to the left side of the chest were more likely than those who received right-sided radiation to develop heart disease during the subsequent two decades. However, left-sided radiation therapy did not increase the risk of death from a heart-related problem.

“Our findings showed that radiation therapy in patients with cancer in the left breast has a small but finite risk of coronary artery disease that may not show up for more than ten years after treatment,” says Harris. “Women receiving radiation to the left side of their chest need to be aware of this risk and take the appropriate steps to monitor their cardiovascular health.”

The group compared heart disease incidence and mortality between 477 women with right-sided early-stage breast cancer and 484 women with left-sided breast cancer who were treated with contemporary radiation oncology techniques (which are more targeted than older approaches) between 1977 and 1994, and were followed for up to 20 years. The rate of death from a cardiac cause was similar between the two groups (6 percent for the left-sided group versus 4 percent for the right-sided group).

However, more women who received radiation to the left side of the chest developed coronary artery disease (25 percent versus 10 percent) or had a heart attack (15 percent versus 5 percent). Moreover, having high blood pressure before therapy increased the risk of heart disease associated with radiation therapy in the left-sided group. Harris noted that recent advances in radiation techniques allow more accurate monitoring of heart volumes, and that further reductions in the amount of heart tissue receiving radiation during


treatment for left-sided breast cancer are achievable. 

In 2001, H. Lee Moffitt Cancer Center & Research Institute earned NCI Comprehensive Cancer Center status in recognition of its excellence in research and contributions to clinical trials, prevention and cancer control. Additionally, Moffitt is a member of the National Comprehensive Cancer Network, a prestigious alliance of the country's leading

cancer centers, and is listed in the U.S. News & World Report as one of the top cancer hospitals in America. Moffitt’s sole mission is to contribute to the prevention and cure of cancer.