Sentinel lymph node biopsy for patients with breast cancer: five-year experience.

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.