ESTRO 2019: 10-Year Follow-up of Whole-Breast Irradiation in Low-Risk Breast Cancer
Posted: Friday, May 3, 2019
The 10-year results of a study in women with hormone receptor–positive “low-risk” breast cancer revealed that women who receive whole-breast irradiation in addition to antihormonal treatment have a significantly lower risk of recurrence and higher disease-free survival. Conducted by the Austrian Breast and Colorectal Cancer Study Group (ABCSG), the ABCSG 8A trial was presented at the European Society for Radiotherapy and Oncology (ESTRO) 2019 Congress in Milan (Abstract O-C-0270).
“In our analysis, the omission of whole-breast irradiation turned out to be the main predictor of in-breast recurrences,” stated Gerd Fastner, MD, of Paracelsus Medical University, Salzburg, Austria, in an ESTRO press release.
In this randomized study, 869 patients received antihormonal therapy after breast-conserving surgery followed by either whole-breast irradiation (n = 439) or observation (n = 430). All participants were considered to have “low-risk” disease, with a G1 or G2 grading, tumors smaller than 3 cm, and a node-negative status.
After 10 years of follow-up, 10 in-breast recurrences were observed in the irradiation cohort compared with 31 in the observation cohort. This finding translated into a 10-year local control rate of 97.5% after radiotherapy versus 92.4% (P < .01) without radiotherapy, respectively. Disease-free survival was significantly higher in the radiotherapy group (94.5% vs. 88.4%, P = .01). In women who underwent sentinel node extirpation alone, disease-free survival was also significantly improved after radiotherapy; however, the same advantage was not seen with whole-breast irradiation after the axillary nodes were removed.
Dr. Fastner explained that the standard practice of radiotherapy has changed in the past decade. “In light of current knowledge, this does not necessarily mean that they have to have whole-breast irradiation nowadays, since partial-breast irradiation has proved to be competitive.”
Disclosure: The study authors’ disclosure information may be found at estro.org.
