Sentinel lymph node mapping with patent blue dye in patients with breast cancer: a retrospective single institution study.

BACKGROUND: Since the end of the last century, sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection (ALND) as standard of care for axillary staging in early breast cancer in patients without any clinical sign of axillary lymph node infiltration. The worldwide most frequently used mapping method consists in the injection of radioactive technetium-99 isotope alone or in combination with blue dye. As a specific infrastructure and dedicated personnel are needed for the use of a radioactive tracer, the CHC in Liege (Belgium) decided to test the use of patent blue dye alone to detect sentinel lymph nodes in a large consecutive cohort of patients and compared the results with radioactive mapping methods and guidelines recommendations.
METHODS: Patent blue dye was used in 456 consecutive patients with early breast cancer who underwent conservative breast cancer surgery or radical mastectomy between 1/1/2000 and 31/12/2007 in a community hospital (CHC Liège, Belgium). After SLNB, an ALND was performed in each patient.
RESULTS: Sentinel lymph nodes were identified in 444 patients among the 456 patients evaluated by this mapping method during this time period, which represents a detection rate of 97.4%. Infiltrated lymph nodes were detected in 32.7% of patients (149/456) while in the 444 patients with sentinel lymph nodes identified and resected, 137 patients have at last one positive lymph node (30.9%). The false negative rate was 4.9% and the predictive negative value was 97.7% with the blue dye mapping method.
CONCLUSIONS: In addition of the simplicity of the method and the large economic advantage, SNLB using blue dye alone showed a quite acceptable performance in our retrospective analysis concerning its ability to find the SLN as well as its reliability to remove the good ones.