Treating DCIS patients with radiation therapy can make low mortality rates even lower
The combination of a lumpectomy and radiation is associated with a slight improvement in a patient’s chance of surviving noninvasive breast cancer, according to a new study published by JAMA Network Open.
The authors explored data from more than 140,000 women in the U.S. who had ductal carcinoma in situ (DCIS) from 1998 to 2014. While 25 percent were treated with lumpectomy alone, more than 46 percent were treated with lumpectomy and radiotherapy. More than 28 percent, meanwhile, were treated with mastectomy alone.
“We sought to measure the extent to which radiotherapy is associated with a reduced risk of breast cancer death in this cohort of women and to identify subgroups of women who might benefit from radiotherapy the most,” wrote lead author Vasily Giannakeas, MPH, with the Women’s College Research Institute in Toronto, and colleagues.
Overall, the 15-year breast cancer mortality rate was 2.33 percent for patients treated with lumpectomy alone, 2.26 percent for patients treated with mastectomy alone, and 1.74 percent for patients treated with lumpectomy and radiation. For all participants, the cumulative mortality rate was 2.03 percent.
In women younger than the age of 50, black women and women with estrogen receptor-negative cancers, radiotherapy had an even greater impact on breast cancer-specific mortality.
“On average, 370 women would need to be treated with radiotherapy to save one life,” the authors wrote. “This count was fewer for black women (115 treated) and for women younger than 50 years (63 treated).”
Similar results have also been reported in patients with invasive cancer, Giannakeas and colleagues added. What leads to these results, however, remains something researchers must investigate further.
“Although the clinical benefit is small, it is intriguing that radiotherapy has this effect, which appears to be attributable to systemic activity rather than local control,” the authors concluded. “How exactly radiotherapy affects survival is an important question that should be explored in future studies.”
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.