JAMA 2013-10-09
Sentinel lymph node surgery after neoadjuvant chemotherapy in patients with node-positive breast cancer: the ACOSOG Z1071 (Alliance) clinical trial.
Abstract
Importance
Sentinel lymph node (SLN) surgery provides reliable nodal staging information with less morbidity than axillary lymph node dissection (ALND) for patients with clinically node-negative (cN0) breast cancer. The application of SLN surgery for staging the axilla following chemotherapy for women who initially had node-positive cN1 breast cancer is unclear because of high false-negative results reported in previous studies.
Objective
To determine the false-negative rate (FNR) for SLN surgery following chemotherapy in women initially presenting with biopsy-proven cN1 breast cancer.
Design, setting, and patients
The American College of Surgeons Oncology Group (ACOSOG) Z1071 trial enrolled women from 136 institutions from July 2009 to June 2011 who had clinical T0 through T4, N1 through N2, M0 breast cancer and received neoadjuvant chemotherapy. Following chemotherapy, patients underwent both SLN surgery and ALND. Sentinel lymph node surgery using both blue dye (isosulfan blue or methylene blue) and a radiolabeled colloid mapping agent was encouraged.
Main outcomes and measures
The primary end point was the FNR of SLN surgery after chemotherapy in women who presented with cN1 disease. We evaluated the likelihood that the FNR in patients with 2 or more SLNs examined was greater than 10%, the rate expected for women undergoing SLN surgery who present with cN0 disease.
Results
Seven hundred fifty-six women were enrolled in the study. Of 663 evaluable patients with cN1 disease, 649 underwent chemotherapy followed by both SLN surgery and ALND. An SLN could not be identified in 46 patients (7.1%). Only 1 SLN was excised in 78 patients (12.0%). Of the remaining 525 patients with 2 or more SLNs removed, no cancer was identified in the axillary lymph nodes of 215 patients, yielding a pathological complete nodal response of 41.0% (95% CI, 36.7%-45.3%). In 39 patients, cancer was not identified in the SLNs but was found in lymph nodes obtained with ALND, resulting in an FNR of 12.6% (90% Bayesian credible interval, 9.85%-16.05%).
Conclusions and relevance
Among women with cN1 breast cancer receiving neoadjuvant chemotherapy who had 2 or more SLNs examined, the FNR was not found to be 10% or less. Given this FNR threshold, changes in approach and patient selection that result in greater sensitivity would be necessary to support the use of SLN surgery as an alternative to ALND.
Trial registration
clinicaltrials.gov Identifier: NCT00881361.
Related Questions
For a young female (<40) with HR-/HER2+ cT1-2N1, ypT1aN0 s/p mastectomy with SLNB, would you offer PMRT?
Thanks for the question. In the seminal PMRT randomized trials of patients treated with adjuvant systemic therapy, PMRT improved overall survival. B-51 was not designed to evaluate the non-inferiority of PMRT omission. Beyond being less conservatively designed to test for superiority of "RNI" with r...
Based on the SENTINA trial, is it reasonable to allow for axillary assessment via SLNB alone (without axillary dissection) after neoadjuvant chemotherapy for an upfront clinically node-positive patient?
False-negative is reduced to 5% or low with dual tracer, taking more than two sentinel nodes out and making sure bx positive node is clipped, localized, and taken out.
Is there any data to support SLNB instead of ALND in patients with clinically N2-3 breast cancer after neoadjuvant chemotherapy?
The sentina trial and acsog trial had Predominant N1 disease and negative predictive value Of SNLN is not known for N2 or N3 disease
What is the sensitivity of SLNB after neoadjuvant chemotherapy for cN0 patients?
The sensitivity of SNLN for clinical N0 disease is high and can be treated like node negative. One has to be cautious about clinical positive patients which normalizes after chemo, as based on ASOCOG and SENTINA trial it can be less than 90% unless due diligence is done like clipping the involved no...
Should axillary imaging be routinely performed in all patients with a new diagnosis of breast cancer?
This issue has been debated but I would argue that patients with a new diagnosis of breast cancer should not undergo routine screening US of the axilla to look for clinically occult disease. The axillary US should be limited to diagnostic imaging for clinically suspicious nodes on clinical exam or b...