CHICAGO―Axillary radiotherapy (RT) offers 5-year survival rates comparable to surgical dissection of the axillary lymph nodes (ALNs), and a lower risk of developing lymphedema, report authors of a European phase 3 double-blind, placebo-controlled AMAROS trial presented at the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting.
The 5-year breast cancer recurrence rates in axillary nodes were surprisingly low overall (0.54% for patients in the lymph node dissection group and 1.03% in the RT group), reported lead study author Emiel J. Rutgers, MD, of the Netherlands Cancer Institute in Amsterdam, The Netherlands.
Patients diagnosed with early-stage breast cancer and with no clinically or radiologically detectable lymph node involvement, but who had positive sentinel lymph node biopsy results, were randomly assigned to undergo either ALN dissection (n=744) or axillary RT (n=681).
“Recurrence rates were extremely low in both groups—far less than we anticipated 12 years ago,” when the study was initiated, Dr. Rutgers said. Both ALN dissection and axillary RT provide “excellent and comparable” locoregional control in patients with positive axillary nodes, he said.
Overall survival (OS) and disease-free survival (DFS) rates at 5 years were also statistically similar between the treatment groups (ALN dissection vs. RT: 92.5% vs. 93.3%; DFS: 92.6% vs 86.9%).
However, lymphedema incidence was “twice as common” among patients who received ALN dissection as RT (28% vs. 14%; P<0.0001), Dr. Rutgers emphasized.
“I am sure these findings will lead to many doctors re-thinking their strategy for treating patients who have a positive sentinel node biopsy,” Dr. Rutgers said, noting that lymphedema can affect patients’ quality of life “indefinitely.”
The study’s quality-of-life findings were equivocal, however, with nonsignificant trends toward more swelling after dissection and more difficulty moving an arm after RT, he said. Using the EORTC-QLQ-C30 (version 3) and QLQ –BR23 (breast cancer module) pain and body image scales to assess quality of life, the coauthors found no significant differences among patients treated with RT and dissection. (These quality-of-life measures might “not capture problems associated with lymphedema,” Dr. Rutgers cautioned.)
“Radiotherapy to axilla is a good—maybe even a better—alternative to surgery because of side effects and extremely good cancer control,” he concluded.