Sentinel lymph node detection for breast cancer: Which patients are best suited for the patent blue dye only method of identification?

Background: The objectives of this study were, first, to define the preoper ative criteria for using solely the blue dye method and, second, to decreas e its operator dependence in predicting axillary lymph node status. Methods: Two hundred fifty-three women consecutively identified with operab le breast cancer underwent sentinel lymph node (SLN) detection by the paten t blue dye method followed by completion axillary lymph node dissection. A standard pathological examination was performed for all SLN. Then, a pathol ogical color quality assessment (PCQA), which checked for the presence of t he blue dye, was performed on the paraffin blocks of the nonmetastatic SLN. Six preoperative identifiable variables likely to influence the detection rate were examined. Results: The surgical detection (sd) rate was 84% (213 of 253) and the PCQA rate was 73% (185 of 253). Only breast size (sd, P = .0005; PCQA, P = .000 7) and body mass index less than or equal to 30 (sd, P = .005; PCQA, P = .0 007) were significant for SLN identification. Multivariate analysis reveale d two independent factors influencing SLN identification: breast size (sd, P = .0001; PCQA, P = .002) and the timing of injection-injection prior to l umpectomy (sd, P = .04). Conclusions: The optimal patient features for identifying the SLN by the pa tent blue dye method are small or medium-sized breasts, low body fat, and t hat the procedure is carried out prior to tumor excision. The PCQA offers a useful second assessment of the surgically removed SLN, introducing an ind ependent element of quality control.