Rodrigo Arrangoiz MS, MD, FACS, FSSO

SENTINA Trial:
- Was a 4-arm, prospective, multicenter cohort study:
  - Of 1,737 patients:
    - That evaluated the role of sentinel lymph node biopsy (SLNB) in patients who had undergone neoadjuvant chemotherapy (NAC) for invasive breast cancer
  - Clinical node status:
    - Was determined by palpation and ultrasound in all patients
  - Ultrasound guided fine-needle aspiration or core biopsy:
    - Was recommended but not mandatory
  - Patients with clinically node-negative (cN-) disease:
    - Underwent SLNB before NAC (Arm A)
  - If the sentinel node (SN) was positive:
    - A second SLNB and axillary lymph node dissection (ALND) was performed after NAC (Arm B)
  - Women who were clinically node positive (cN+) underwent NAC, and those who converted to being cN- also had SLNB and axillary lymph node dissection (Arm C)
  - Only patients whose clinical nodal status remained positive (ycN1) underwent axillary dissection without sentinel lymph node biopsy (arm D)
When SLNB was done before NAC:
- No difference in the detection rate was found between the combined (radiocolloid and blue dye) and single agent (radiocolloid alone) detection techniques:
  - 99.5% vs. 98.8%
However, when SLNB was done after NAC:
- The addition of blue dye increased the detection rate and the number of nodes retrieved
- Dual tracer detection rate was:
  - 76% after chemotherapy in patients who also had SLNB prior to chemotherapy and 88% in those who converted from cN+ to cN- with NAC and had only one SLNB
For patients who were confirmed node positive by SLNB biopsy prior to NAC:
- The FNR of repeat SLNB after NAC was 51.6%
For patients who converted from cN+ to cN- with NAC:
- FNR of SLNB after NAC was 14.2%:
  - However, in the cN+ to cN- group:
    - The FNR was below 10%, for patients who had 3 or more lymph nodes removed and if both blue dye and radiocolloid were used
      - In these cases, the FNR was 8.6%
References
- Kuehn T, Bauerfeind I, Fehm T, Fleige B, Hausschild M, Helms G, et al. Sentinel-lymph-node biopsy in patients with breast cancer before and after neoadjuvant chemotherapy (SENTINA): a prospective, multicentre cohort study. Lancet Oncol.2013;14(7):609-618.
- Schwentner L, Helms G, Nekljudova V, Ataseven B, Bauerfeind I, Ditsch N, et al. Using ultrasound and palpation for predicting axillary lymph node status following neoadjuvant chemotherapy – Results from the multi-center SENTINA trial. Breast. 2017;31:202-207.