Background: There is ongoing debate regarding the optimal sequence of sentinel lymph node (SLN) biopsy and neoadjuvant chemotherapy (CTX) for breast cancer. We report the accuracy of comprehensive pre-neoadjuvant CTX and post-neoadjuvant CTX axillary staging via ultrasound imaging, fine-needle aspiration (FNA) biopsy, and SLN biopsy.
Methods: From 2001 to 2004, 91 neoadjuvant CTX patients at the University of Michigan Comprehensive Cancer Center underwent axillary staging by ultrasonography, ultrasound-guided FNA biopsy, SLN biopsy, or a combination of these.
Results: Axillary staging was pathologically negative by pre-neoadjuvant CTX SLN biopsy in 53 cases (58%); these patients had no further axillary surgery. In 38 cases (42%), axillary metastases were confirmed at presentation by either ultrasound-guided FNA or SLN biopsy. These 38 patients underwent completion axillary lymph node dissection (ALND) after delivery of neoadjuvant CTX. Follow-up lymphatic mapping was attempted in 33 of these cases, and the SLN was identified in 32 (identification rate, 97%). One third of these cases were completely node negative on ALND. Residual metastatic disease was identified in 22 cases, and the SLN was falsely negative in 1 (4.5%).
Conclusions: Patients receiving neoadjuvant CTX can have accurate axillary nodal staging by ultrasound-guided FNA or SLN biopsy. In cases of documented axillary metastasis at presentation, repeat axillary staging with SLN biopsy can document the post-neoadjuvant CTX nodal status. This strategy optimizes pre-neoadjuvant CTX and post-neoadjuvant CTX staging information by distinguishing the patients who are node negative at presentation from those who have been downstaged to node negativity and offers the potential for avoiding unnecessary ALNDs in both of these patient subsets.