Sentinel lymph node biopsy after neoadjuvant chemotherapy in a patient with operable breast cancer.

PURPOSE: This study was undertaken to assess the feasibility of performing a sentinel lymph node biopsy (SLNB) for a patient with operable breast cancer after undergoing neoadjuvant chemotherapy (NAC).

METHOD: Between January 2002 and December 2003, women with primary breast cancer who had a breast tumor measuring larger than 3 cm in unilateral diameter were eligible for NAC. All patients who had completed NAC underwent lymphatic mapping with labeled (99m)Tc phytate on the day before surgery. Sentinel lymph node biopsy followed by a full axillary lymph node (AXLN) dissection (ALND) was performed in all patients. Sentinel lymph nodes (SLN) were sent for a frozen-section examination.

RESULTS: The rate of SLN identification was 71%. Both the sensitivity and negative predictive value of SLNB were 100%. The false negative rate was 0%. When candidates for SLNB were restricted to patients with a breast tumor measuring less than 3 cm and clinically negative nodes after NAC, the rate of SLN identification increased to 93% from 71% while still maintaining the 0% false negative rate.

CONCLUSION: Sentinel lymph node biopsy after NAC is therefore considered to be a feasible and accurate method to predict the AXLN status in patients who have a breast tumor measuring less than 3 cm in unilateral diameter and a clinically negative AXLN status at the time of surgery after NAC.