This study offers scientific evidence to what was long thought to be true but never proven: that improvements in radiation techniques and delivery have greatly impacted radiation-associated cardiac mortality.
"For a while now, physicians have been telling women that receiving radiation for breast cancer is so much safer today than it was before. People believed it, but there really was very little scientific evidence or studies examining the relationship between advancements in radiation therapy to ischemic heart disease," says Sharon Giordano, M.D., the study's lead author and an assistant professor in M. D. Anderson's Department of Breast Medical Oncology. "Before now, there were no studies that looked at the effects of radiation to the heart over time. Most previous analyses had involved women who had been treated in the 1950s, 1960s and 1970s, decades not considered in the era of modern medicine.
"Comparing women with breast cancer on the left side where the heart is located (therefore, more radiation is delivered to the heart) versus those with disease on the right side gave us a perfect study to examine radiation-induced toxicity to the heart and cardiac mortality," she continues.
Giordano and her colleagues used information from the National Cancer Institute SEER database (Surveillance, Epidemiology, and End Results), the authoritative source of information on cancer incidence and survival in the United States. The researchers analyzed SEER data from 1973 to 1989 on 27,283 women - 13,998 had left
Contact: Laura Sussman
University of Texas M. D. Anderson Cancer Center