Background
Surgical management of the axilla in breast cancer has evolved greatly in the past 20 years. Sentinel lymph node biopsy (SLNB), which was first investigated in the early 1990s, has replaced routine axillary lymph node dissection with its associated greater morbidity in early-stage node-negative patients. However, the role and timing of SLNB, management of the axilla, and technical aspects of the procedure in patients treated with neoadjuvant chemotherapy (NACT) are matters of controversy. Although data on SLNB and NACT are accumulating, the accuracy of SLNB to stage the axilla and the value of SLNB in relation to long-term outcomes remain to be seen.
Objectives
To evaluate the use of 1% methylene blue (MB) as a single agent tracer for the detection of sentinel lymph node after NACT for locally advanced breast cancer with the calculation of the identification rate and false-negative rates (FNRs).
Patients and methods
A total of 31 patients with cT3-4(a-c) cN1-3, M0 breast cancer after NACT who showed downstaging of their nodal status to N0 were injected with 1% MB, retroareolarly or peritumorally, followed by axillary lymph node dissection, and the results were studied to detect the identification rate and FNR.
Results
The median age of the patients was 48 years, with 83.8% of the patients above the age of 40 years. The identification rate was found to be 83%, and a FNR of 11.5% was detected. FNRs were found to be less when more than three sentinel lymph nodes were dissected, with no statistically significant difference relating FNRs to the initial nodal state of the disease.
Conclusion
The use of 1% MB after NACT showed a comparable identification rate and FNRs to other single tracer techniques, yet all single tracer techniques are lesser than ideal in this group of patients.