The study represents the first long-term comparison of the two methods’ effect on breast cancer survival and recurrence, said Thomas B. Julian, MD, Associate Director of the Breast Care Center at AGH and one of the clinical trial’s principal investigators, along with Norman Wolmark, MD, who serves as Chair of both the NSABP and the Department of Human Oncology at AGH.
The study, which enrolled 5,611 women over a period of five years, showed no significant difference in overall survival, disease-free survival, or regional control of cancer between the sentinel node resection alone versus complete axillary dissection of the lymph nodes.
“Sentinel node resection is now clearly the standard of care for women with clinically node-negative breast cancer, which comprise the majority of patients,” Dr. Julian said. “Many women with this disease are now able to avoid the potential complications of full lymph node removal and know that their cancer is being effectively treated.”
Removing all lymph nodes from the underarm area carries the risk of difficult and sometimes permanent complications ,including lost sensation in the back of the arm, tingling, weakness and swelling (lymphedema).
Sentinel nodes are normally the first lymph nodes to receive drainage as well as cancer cells from the breast tumor. Doctors can find the sentinel nodes and remove them with a small surgical procedure. If no cancer is found, removal of the remaining lymph nodes is not necessary.
The NSAPB study was the largest prospective randomized Phase III trial designed to determine that sentinel node resection alone results in the same survival and regional control as axillary dissection.
Participants across North America and Puerto Rico were randomly assigned to undergo either a sentinel node resection with an axillary dissection, or to a sentinel node biopsy alone followed by axillary dissection if a sentinel node biopsy showed cancer.
Overall eight–year survival was 91.8 percent for the sentinel node-alone patients and 90.3 percent for those who also had an axillary dissection. Disease-free survival rates were 82.4 percent for the sentinel node group and 81.5 percent for the axillary group. Local and regional recurrence of cancer happened 61 times in the sentinel node group and 63 times in the axillary group.
“These results validate sentinel node resection as a safe and effective treatment for node-negative breast cancer patients,” Dr. Julian said.