Among women with early breast cancer and no evidence of cancer in the sentinel lymph nodes, sentinel lymph node biopsy alone is as effective as more extensive lymph node surgery. These results 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. A sentinel lymph node biopsy involves the removal of only these nodes. If cancer is found in the sentinel nodes, most women undergo additional lymph node removal. If the sentinel nodes are free of cancer, however, women may not require any additional lymph node removal. Avoidance of extensive lymph node removal reduces the risk of side effects such as lymphedema (swelling).
To explore whether the two approaches to lymph node evaluation (sentinel lymph node biopsy and axillary lymph node dissection) produce similar breast cancer outcomes, researchers conducted a study among 5,611 women with operable, clinically node-negative, invasive breast cancer. Study participants were assigned to sentinel lymph node biopsy and axillary lymph node dissection or sentinel lymph node biopsy alone (with axillary lymph node dissection only if the sentinel node was positive).
Seventy-one percent of the study participants had negative sentinel lymph nodes and have been followed for an average of close to eight years.
These results suggest that when the sentinel lymph node is negative, sentinel lymph node biopsy alone (with no additional lymph node removal) is safe and effective.
Reference: Krag DN, Anderson SJ, Julian TB et al. Primary outcome results of NSABP B-32, a randomized phase III clinical trial to compare sentinel node resection (SNR) to conventional axillary dissection (AD) in clinically node-negative breast cancer patients. Presented at the 2010 annual meeting of the American Society of Clinical Oncology. June 4-8, 2010. Chicago, IL. Abstract LBA 505.