(HealthDay News) — The omission of radiotherapy (RT) does not affect overall survival at 10 years after breast conserving surgery (BCS) for older women with hormone receptor-positive breast cancer, according to a study presented at the annual San Antonio Breast Cancer Symposium, held virtually from Dec. 8 to 11.
Ian H. Kunkler, from the University of Edinburgh in the United Kingdom, and colleagues examined the impact of locoregional RT after BCS on long-term outcomes in older patients receiving appropriate systemic therapy. A total of 1,326 patients aged ≥65 years, with axillary node-negative, hormone receptor- positive breast cancer were randomly assigned to either receive or not receive (658 and 668, respectively) whole breast RT; patients were followed for a median of 7.3 years.
The researchers found that at 10 years, ipsilateral breast tumor recurrence was 9.8 and 0.9 percent in the no RT and RT arms, respectively, with a hazard ratio of 0.12 (95 percent confidence interval, 0.05 to 0.31; P < 0.0001) for those receiving RT. Regional recurrence differed significantly (2.3 versus 0.5 percent with no RT and with RT, respectively; P = 0.014), but no differences were seen in contralateral breast cancer (P = 0.20) or distant metastases (P = 0.07). Breast cancer-free survival was 12.7 and 6.6 percent for the no RT and RT arms, respectively. At 10-years, overall survival was 80.4 and 81.0 percent without and with RT (P = 0.68).
“We believe that omission of radiation therapy after breast-conserving surgery should be an option for older patients,” Kunkler said in a statement.