Sentinel lymph node biopsy in breast cancer patients treated with neoadjuvant chemotherapy

Abstract

BACKGROUND: Sentinel lymph node biopsy (SLNB) is a widely used staging method for patients with early breast cancer. Neoadjuvant chemotherapy modifies the anatomical conditions in the breast and axilla, and thus SLNB remains controversial in patients treated preoperatively. The aim of this study was to demonstrate the reliability and accuracy of this procedure in this particular group of patients. METHODS: The retrospective study analyzed medical records of patients diagnosed with primary breast cancer between the years 2005 and 2009. Of the patients treated by neoadjuvant therapy, 343 underwent lymphatic mapping to identify sentinel lymph nodes, and these were included in the analysis. RESULTS: The overall detection rate of sentinel lymph nodes was 80.8%. It was strongly influenced by clinical lymph node status (significantly higher success rate in lymph node-negative patients); higher detection rates were also associated with age <50 years, estrogen receptor positivity, lower proliferation index, and absent lymphovascular space invasion. The false-negative rate was 19.5% and was only marginally significantly dependent on lymphovascular space invasion. The overall accuracy of the method was 91.5%. CONCLUSIONS: By using the present technique, sentinel lymph node biopsy cannot be recommended as a reliable predictor of axillary lymph node status when performed at the authors' institution after neoadjuvant chemotherapy. Infrequent use of blue dye for lymphatic mapping, low number of resected sentinel lymph nodes, and absence of any selection among patients included in the study could be the main factors responsible for the low detection rate and high false-negative rate. Cancer 2011;117:4606-

Relationship Between the Lymphatic Drainage of the Breast and the Upper Extremity: A Postmortem Study

“…18 Recently, the issue of lymphatic drainage in breast cancer after chemotherapy has been highly debated, where the success of lymphatic mapping and sentinel node identification may be decreased. 19 …”

Reliability of Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer Patients

“…However, identification rates from recent independent reports show significant variation, ranging from 75.7% to 98.7%, which is often explained by study population heterogeneity. Clinicopathologic factors such as initial clinical nodal status [17,22], residual tumor size [19], degree of tumor response to NAC [21], age, ER status, proliferation index, and lymphovascular invasion [22] have been suggested to affect identification rates. However, no single clinicopathologic factor has consistently been shown to affect the identification rate of SLNB after NAC.…”

Accuracy of sentinel lymph node biopsy after neo-adjuvant chemotherapy in patients with locally advanced breast cancer and clinically positive axillary nodes

“…Based on the SLNB validation studies mentioned above, it would be reasonably legitimate to introduce the SLNB procedure also in the context of NAC. However, one frequent adverse effect of NAC is the anatomical alteration of the lymphatic drainage, with lymphatic vessels disrupted by tumor, inflammation or fibrosis, or blocked by necrotic and/or apoptotic cells [17]: in addition, NAC could induce a non-uniform tumor regression in the axillary modes, being most effective in some nodes but not in others [17][18][19]. These events could prevent a proper diffusion of the scintigraphic tracer during lymphatic mapping, in the one hand, and contribute to a reduction in the rate of successful SLN identification and, more importantly, an increase in the rate of false-negative SLN [18][19][20].…”

“…The finding of false negative cases is most probably due to alterations of the lymphatic drainage that deviate the radioactive tracer towards node(s) free of disease. Several factors could alter the lymphatic drainage, e.g heavily fatty or metastatic nodes impeding normal lymph flux, tumor cells infiltrating lymphatic vessels and/or the use of NAC itself that provokes fibrosis, necrosis and granulation tissue formation, or could produce a nonhomogeneous disease regression, being more effective in the SLN than in other nodes [17,18,19,32]. In patients whose axilla remains clinically involved after NAC, it is thus advisable to perform an accurate and extensive clinical palpation of the axillary nodes during surgery in order to identify, remove and analyze any suspicious node, as recommended by International Guidelines M A N U S C R I P T…”