Sentinel lymph node biopsy using single-agent mapping tracer (blue dye) after neoadjuvant chemotherapy in a Brazilian cohort of breast cancer patients. Real world evidence

Abstract

To reduce false-negative rates (FNR) in sentinel lymph node biopsy (SLNB) of clinically positive (cN+) axilla in patients undergoing neoadjuvant chemotherapy (NAC). The removal of three or more lymph nodes with dual-tracer mapping including a radioisotope was used. However, in the Brazilian Unified Health System, the radioisotope tracer is not feasible in some hospitals. We conducted a crosssectional study to evaluate the detection rate of sentinel lymph node (SLN) in patients who converted from cN+ to ycN0 after NAC using blue dye as a single-agent mapping tracer. Methods: During the period of March 2018 to September 2019, 34 patients who underwent NAC with cN+ who converted to ycN0 were enrolled in the study. The SLNB was performed using blue dye as a single-agent mapping followed by axillary lymph node dissection (ALND). Results: The detection rate of sentinel lymph node was of 85.3%, being SLNB not possible for five patients (14.7%), due to fibrosis. The mean number of removed SLN was 2.5. Conclusions: The use of blue dye as a single-agent mapping tracer demonstrated an acceptable detection rate of 85.3%. Although the FNR was possible to be determined, the small sample size might overestimate this rate. The removal of three or more lymph nodes with single-agent mapping tracer might be indicated for breast cancer patients who converted to ycN0 after NAC in the Brazilian health public services, in which radioisotope tracer is not suitable.

Improved false-negative rates using a novel patient selection flowchart in initially biopsy-proven node-positive breast cancer undergoing blue-dye alone guided sentinel lymph node biopsy after neoadjuvant chemotherapy

“…Besides, it is reported that in the real world, the FNR of marking and removing a previously positive axillary lymph node for breast cancer after NAC ranges from 0% to 28.6%. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] So this clippedmarked method may not decrease FNR in all populations. However, we found differences in the SLN FNR between those cases when the clip was identi ed in the SLN versus those cases with the clip identi ed in the ALND specimen, and this difference may be clinically relevant.…”

Management of the positive sentinel lymph node following neoadjuvant chemotherapy: results of a survey conducted with breast surgeons

“…The SBM adopts the international guideline recommendations for the technique of SLN biopsy. However, since most of the oncology institutes in the country do not have access to nuclear medicine services, blue dye alone tends to be used as a lymph node marker for the majority of patients [ 16 , 17 ].…”

“…Regardless of these recommendations following NACT, in recent years, there has been a growing trend towards omitting additional axillary surgery despite the lack of evidence from randomised clinical trials focusing on this particular clinical endpoint. In routine clinical practice, breast surgeons are sometimes confronted with different situations such as when SLN biopsy is negative on frozen section but found to be positive/metastatic on paraffin section, with the surgeon then making the decision not to return the patient to the operating room to reoperate the axilla [15][16][17][18]. Indeed, although guidelines recommended AD if there is any residual disease after NACT, in practice, if residual disease is not detected at the time of frozen section biopsy but only in the definitive result, regional nodal irradiation (RNI) without AD can be considered by the multidisciplinary team [14].…”