Emergence of Sentinel Node Biopsy in Breast Cancer as Standard-of-Care in Academic Comprehensive Cancer Centers

BACKGROUND Ongoing clinical trials are addressing the accuracy and safety of sentinel node biopsy (SNB) in the treatment of breast cancer; however, SNB is already increasingly being used in clinical practice. This study examined the extent and time trends of the use of SNB in stage I and II breast cancer patients. METHODS Clinical data were collected from stage I and II (tumor size < or =5.0 cm) breast cancer patients (n = 3003) who were treated at five comprehensive cancer centers between July 1, 1997, and December 31, 2000. Axillary surgery was classified as SNB alone, SNB + axillary node dissection (AND), AND alone, or none. Patterns of use of axillary surgery were summarized as the percentage of patients receiving each surgery type. The statistical significance of time trends for the use of SNB alone was analyzed by logistic regression models. All statistical tests were two-sided. RESULTS Overall, SNB alone was used in 13% of patients, SNB + AND in 22%, AND alone in 59%, and no axillary surgery in 6%. Use of SNB alone was statistically significantly associated with breast-conserving surgery of both smaller (< or =2 cm) and larger tumors (2-5 cm) (P