Accuracy and Limitations of Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer Patients with Positive Nodes

Abstract

Background. Axillary surgical management in patients with node-positive breast cancer at the time of diagnosis converted to negative nodes through neoadjuvant chemotherapy (NAC) remains unclear. Removal of more than two sentinel nodes (SLNs) in these patients may decrease the false negative rate (FNR) of sentinel lymph node biopsies (SLNBs). We aim to analyse the detection rate (DR) and the FNR of SLNB assessment according to the number of SLNs removed. Methods. A retrospective study was performed from October 2012 to December 2018. Patients with invasive breast cancer who had a clinically node-positive disease at diagnosis and with a complete axillary response after neoadjuvant chemotherapy were selected. Patients included underwent SLNB and axillary lymph node dissection (ALND) after NAC. The SLN was considered positive if any residual disease was detected. Descriptive statistics were used to describe the clinicopathologic features and the results of SLNB and ALND. The DR of SLNB was defined as the number of patients with successful identification of SLN. Presence of residual disease in ALND and negative SLN was considered false negative. Results. A total of 368 patients with invasive breast cancer who underwent surgery after complete NAC were studied. Of them, 85 patients met the eligibility criteria and were enrolled in the study. The mean age at diagnosis was 50.8 years. Systematic lymphadenectomy was performed in all patients, with an average of 10 lymph nodes removed. The DR of SLNB was 92.9%, and the FNR was 19.1. The median number of SLNs removed was 3, and at least, three SLNs were obtained in 42 patients (53.2%). When at least three sentinel nodes were removed, the FNR decreased to 8.7%. Conclusions. In this cohort, the SLN assessment was associated with an adequate DR and a high FNR. Removing three or more SLNs decreased the FNR from 19.1% to 8.7%. Complementary approaches may be considered for axillary lymph node staging after neoadjuvant chemotherapy. The study was approved by our institution’s ethics committee (Instituto de Investigacion Sanitaria Hospital 12 de Octubre (imas12), Universidad Complutense de Madrid, Madrid, Spain) (https://clinicaltrials.gov/ct2/show/NCEI:20/0048).

Feasibility of Sentinel Lymph Node Biopsy in Breast Cancer Patients with Axillary Conversion after Neoadjuvant Chemotherapy—A Single-Tertiary Centre Experience and Review of the Literature

“…In their study, Aragon-Sanchez et al [ 42 ] retrospectively analysed the accuracy of SLNB after neoadjuvant chemotherapy in 85 patients who were initially cN1 and converted to cN0 following treatment. Their research revealed that SLNB demonstrated an adequate IR of 92.9%, but with a relatively high FNR of 19.1%.…”

“…The inclusion criteria were met by 20 papers, which were finally included in this qualitative review. Most researcher groups (n = 11) used a combination of 99m Tc-labelled radioisotopes and BD for their SLN mapping [ 24 , 28 , 29 , 30 , 31 , 32 , 37 , 38 , 39 , 40 , 41 ], while nine studies performed SLN identification through radioisotopic mapping alone [ 9 , 18 , 26 , 33 , 34 , 35 , 36 , 42 ]. In all papers, SLNB was followed by ALND to ensure the accurate assessment of the axilla.…”

“…Considering the treatment response in patients who received NAC, several studies indicated that positive lymph node axilla can be converted to pathologically negative status with the use of NAC in about 32–74% of patients [ 9 , 19 , 30 , 42 , 51 , 57 ]. Newman et al [ 31 ] described a ycN0 conversion rate of 32%, while Dominici et al [ 58 ] reported a pathologic complete response rate of 74%, observed in the 109 women included in their study.…”

Comparing Methods for Targeted Axillary Dissection in Breast Cancer Patients: A Nationwide, Retrospective Study

“… 8 However, only 32.0-56.4% of patients staged by SLNB have three or more SNs identified. 3 , 6 , 9 , 10 The development of a less-invasive staging technique for lymph node-positive patients receiving NACT seems imperative, considering that 31.4-63.0% of patients have axillary complete pathologic response (ax-pCR). 3 , 5 , 11 – 13 These patients do not benefit from axillary lymph node dissection (ALND) but are nevertheless imposed to the possible morbidity associated with the procedure.…”