Background: Sentinel lymph node biopsy (SLNB) is rapidly gaining acceptance as a diagnostic tool for staging breast cancer.
Objective: Analyze trends among surgeons and facilities in Kaiser Permanente Northern California (KPNC) in adopting SLNB to stage cases of breast cancer and assess success in locating the sentinel node.
Methods: Retrospective review of data for patients whose breast cancer was staged using SLNB and axillary lymph node dissection between July 1997 through December 2002 at KPNC. Rates of false-negative results were calculated and stratified by surgeons' experience with SLNB.
Results: The number of SLNB procedures performed each month increased steadily from fewer than ten (in late 1998) to about 80 per month (in mid-2002) and were done at 17 facilities. Of the 132 surgeons who performed SLNB, most had done fewer than 15 procedures. The false-negative result rate overall was 6.53% (95% CI 4.75%, 8.73%); for surgeons who performed <30 procedures the rate was 8.58% (95% CI 5.52%, 12.60%); for surgeons who performed 20 to 30 procedures the rate was 13.08% (95% CI 7.34%, 20.98%); and for surgeons who performed more than 30 procedures the rate was 5.05% (95% CI 3.07%, 7.78%).
Conclusions: SLNB is rapidly being adopted at KPNC to stage cases of breast cancer and surgeons achieve an acceptable 6.53% false-negative result rate overall. The higher false-negative rate for surgeons who performed 20 to 30 procedures suggests that departments should expand efforts to monitor and proctor these surgeons.