Axillary radiotherapy is a safe alternative to axillary lymph-node surgery and can reduce the risk of lymphedema, according to data presented on June 3 at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago.
Researchers presented findings from the AMAROS -- or After Mapping of the Axilla: Radiotherapy or Surgery -- European phase III clinical trial. Results showed that axillary radiotherapy and lymph-node surgery resulted in equivalent overall and disease-free survival at five years after treatment for women with sentinel-lymph-node-positive early breast cancer. However, a debilitating side effect known as lymphedema was twice as common among women who underwent surgery.
Lead study author Dr. Emiel Rutgers, from the Netherlands Cancer Institute in Amsterdam, and colleagues enrolled 4,806 clinically node-negative patients with early-stage, invasive breast tumors that were up to 5 cm in size. Of those patients who had a positive sentinel-lymph-node biopsy, 744 were randomly assigned to lymph-node surgery and 681 to axillary radiotherapy. The median follow-up period was six years.
Overall, five-year breast cancer recurrence rates in the axillary nodes were low: 0.54% in the lymph-node surgery group and 1.03% in the axillary radiotherapy group. There were no significant differences between the two groups in terms of estimated five-year overall survival (92.5% to 93.3%) and disease-free survival (82.6% to 86.9%). But in the first year, 40% of patients who underwent lymph-node surgery had lymphedema, compared with 22% of those who had axillary radiotherapy. At five years, the rates were 28% and 14%, respectively.
"I am sure these findings will lead to many doctors rethinking their strategy for treating patients who have a positive sentinel-lymph-node biopsy," Rutgers said in an ASCO statement.
