Axillary and extra-axillary lymph node recurrences after a tumor-negative sentinel node biopsy for breast cancer using intralesional tracer administration.

Background: At our institution, tracer fluids are administered in the primary breast cancer and, in addition to the ones in the axilla, sentinel nodes outside the axilla are rigorously pursued. The objective of the present study of sentinel node-negative breast cancer patients was to determine the lymph node recurrence rates in the axilla and elsewhere, the false-negative rates, and the survival.

Methods: Between January 1999 and November 2005, 1,019 breast cancer patients underwent a sentinel node biopsy. In 748 of them, 755 sentinel node biopsies did not reveal a tumor-positive sentinel node and they did not undergo axillary node dissection. Metastases were revealed in 284 sentinel node biopsies performed in the remaining 271 patients: 247 in the axilla, 20 outside the axilla, and 17 both in the axilla and elsewhere. The median follow-up duration was 46 months.

Results: Two of the 748 sentinel node-negative patients developed an axillary lymph node recurrence (0.25%) and two others developed a supraclavicular lymph node recurrence (0.25%). The overall lymph node recurrence rate was 0.5%. The false-negative rates were 1.4% overall, 0.8% for the axilla, and 5.1% for the extra-axillary nodes. After five years, 95.9% of all sentinel node-negative patients were alive and 89.7% were alive without evidence of disease.

Conclusion: The low recurrence and false-negative rates and promising survival figures show that our lymphatic mapping method with intralesional tracer administration is accurate for the axilla. Outside the axilla, 5.1% of involved sentinel nodes were missed.