Among women with early-stage breast cancer and small amounts of cancer (micrometastases) in the sentinel lymph node, removal of additional lymph nodes (completion axillary lymph node dissection) does not appear to improve overall survival. The results of this study were presented at the 2010 annual meeting of the American Society of Clinical Oncology.
For women with early breast cancer, determining whether the cancer has spread to the axillary (under the arm) lymph nodes is an important part of cancer staging. Evaluation of the axillary nodes may involve either an axillary lymph node dissection (ALND), in which many lymph nodes are surgically removed and evaluated or a less extensive procedure known as a sentinel lymph node biopsy.
The sentinel nodes are the first lymph nodes to which cancer is likely to spread. If the sentinel nodes are free of cancer, no further lymph node evaluation is performed. If the sentinel nodes contain cancer, however, most women then undergo ALND to remove additional nodes. This additional lymph node surgery has been shown to help control cancer locally, but the effect on survival has been controversial. Establishing the benefits of completion ALND is important because it can cause significant side effects such as pain, discomfort, and swelling (lymphedema).
To evaluate the effects of ALND in breast cancer patients with micrometastases in the sentinel node, researchers conducted a Phase III study among 991 women. Half the women underwent completion ALND, and half did not.
- Five-year overall survival was 91.9% among women who underwent ALND and 92.5% among women who did not undergo ALND.
- Disease-free survival was 82.2% among women who underwent ALND and 83.8% among women who did not undergo ALND.
- The rate of local/regional recurrence (recurrence in or near the breast) was 4.3% among women who underwent ALND and 3.4% among women who did not undergo ALND.
In a prepared statement, the lead author of the study explained, “Our findings suggest that there may not be a benefit to removing more lymph nodes than the sentinel node only, and that women can avoid the risk of additional side effects that come with more extensive lymph node removal. Axillary lymph node dissection will still be needed in some cases, but these findings show it may be necessary for far fewer women.”
Reference: Giuliano AE, McCall LM, Beitsch PD et al. ACOSOG Z0011: A randomized trial of axillary node dissection in women with clinical T1-2 N0 M0 breast cancer who have a positive sentinel node. Presented at the 2010 annual meeting of the American Society of Clinical Oncology. June 4-8, 2010. Chicago, IL. Abstract CRA 506.