Core Concepts
SLNB following NACT is safe and effective, but data from randomized trials are lacking.
Abstract
Abstract and Introduction:
- SLNB is the gold-standard for axillary staging in early breast cancer.
- NACT enables downstaging, reducing surgery impact and morbidity.
- Controversy exists regarding SLNB role post-NACT due to lack of randomized trials.
Clinically Negative Nodes at Diagnosis and SLNB After NACT:
- SLNB post-NACT in cN0 patients shows FNRs around 10%.
- Studies indicate low axillary recurrence rates post-SLNB.
- Meta-analyses confirm SLN identification rates and FNRs.
Initially Positive Axilla (cN1/2) and Negative SLNB Following NACT:
- FNRs for SLNB in cN1/2 patients post-NACT were considered high.
- Studies show techniques to reduce FNRs, such as clipping the lymph node.
- Single-center data suggest low axillary recurrence rates post-SLNB.
Positive SLN Following NACT:
- Trend to omit axillary dissection in patients with positive SLN post-NACT.
- Studies show high residual cancer burden post-NACT.
- Controversy exists regarding oncological outcomes and axillary dissection omission.
Omitting Axillary Surgery in Good Responders:
- SLNB provides prognostic information with less morbidity than axillary dissection.
- Debate on avoiding axillary surgery in specific cases with excellent responders.
- Importance of evaluating residual disease for adjuvant therapy decisions.
Stats
"FNRs are generally acceptable (≤10%)".
"SLN identification rate was 90.9%, FNR of 10.5%".
"Overall FNRs reported by studies for patients submitted to NACT were 14.2%, 12.6% and 13.3%".
"FNR of 7.2% was found in a subgroup of patients in whom the metastatic lymph node was marked with a clip prior to NACT".
"A FNR of 7.2% for the clipped lymph node technique and 4.2% for the I-125 seed technique".
"SLNB will identify residual disease in more than 50% of cases in patients with initially positive axilla who achieve clinical complete response to NACT".
"Residual disease in axillary lymph nodes was found in 1.0%, 1.6%, 2.1% and 4% of cases of HER2-positive/HR-negative, triple-negative, HER2-positive/HR-positive and HR-positive/HER2-negative tumors, respectively".
Quotes
"SLNB following NACT has been performed over the years, principally on the basis of FNRs similar to those found with upfront surgery."
"The efforts made to reduce the FNR in these circumstances reflect the absence of data from randomized clinical trials on oncological safety."
"The advances made in these NACT regimes, with the addition of new drugs and a more appropriate selection of patients has, on the other hand, resulted in a high rate of pathologic complete response."