Sentinel lymph node--why study it: implications of the B-32 study.

Surgical removal of the regional lymph nodes by a level I and level II axillary dissection remains the standard of care for patients with surgically resectable breast cancer. Axillary dissection provides accurate pathologic staging and excellent regional disease control, and likely provides a small benefit in patient survival. Axillary dissection, however, is associated with significant patient morbidity. Sentinel lymph node (SLN) biopsy procedures have been found to provide very accurate pathologic staging when compared to axillary dissection; however, their effect on regional disease control and patient survival is not yet known. The National Cancer Institute (NCI) has sponsored a Phase III prospective, randomized clinical trial (the B-32 trial) through the National Adjuvant Breast and Bowel Project (NSABP), to compare results of patients treated with SLN biopsy alone vs. SLN biopsy with completion axillary node dissection in patients with clinically node-negative breast cancer. Results of this trial will provide evidence of the safety of SLN biopsy procedures in the management of patients with breast cancer.