Assessing the impact of neoadjuvant chemotherapy on the management of the breast and axilla in breast cancer.

Background: Nodal status is a sensitive prognostic indicator in breast cancer. Axillary metastases may be an indication for neoadjuvant systemic therapy. The aims of this study were to compare pathologic response rates to neoadjuvant chemotherapy (NAC) in the breast and axilla across different molecular subtypes of breast cancer and to compare the predictive value of axillary assessment before and after chemotherapy in determining final nodal status in this cohort of patients.

Patients And Methods: The cohort comprised patients undergoing NAC from 2003 to November 2012. Data regarding patient and tumor characteristics, management, and outcomes were obtained from a prospectively maintained database and analyzed using PASW Statistics, version 18 (SPSS Inc, Chicago, IL).

Results: Two hundred two cancers were identified in 196 patients. One hundred thirty-one (65%) diagnostic axillary procedures were performed, 105 (80%) before NAC, of which 93 (89%) were positive. In 28 (30%), downstaging was noted before NAC. Human epidermal growth factor receptor 2 (HER2) subtypes had the highest rate of complete pathologic response (n = 11 [61%]) and negative axillary clearance (AXCn) (n = 11 [69%]). Of 177 AXCns, 68 (38%) were negative before NAC.

Conclusion: AXCn in patients undergoing NAC remains controversial. HER2 subtypes are less likely to have axillary involvement after NAC and may demand different management.