Timing of Axillary Staging

Abstract

Optimal timing of axillary staging in patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy remains a contentious issue among surgical oncologists. Our group at the University of Michigan reported a comprehensive approach of staging the axilla prior to chemotherapy (CTX) using a combination of ultrasound, fine-needle aspiration biopsy, and sentinel lymph node biopsy. The utility of these procedures, in our opinion, is threefold, and will be addressed below. From a purely clinical perspective, it has been well documented that physical examination of the axilla is notoriously inaccurate. Confirmation of axillary disease prior to CTX is a key point in therapeutic decision making, and at the time of diagnosis, it may solidify the decision to proceed with neoadjuvant CTX altogether. Moreover, as shown by our data and others, use of adjuvant nodal and postmastectomy radiation may reduce local recurrence rates in those patients whose axillae are downstaged by CTX. These patients may not be offered these therapies if the axilla is assessed after completion of CTX. Moreover, as discussed in our publication, there is prognostic utility to obtaining axillary status prior to initiation of CTX. Other authors have shown a prognostic benefit in both overall and disease-free survival in patients with no residual axillary disease after CTX. In our series, axillary response to CTX was inversely correlated with distant relapse. The implications of this finding may impact not only the immediate adjuvant setting, but longterm decision making as well. Furthermore, in this dawn of molecular diagnostics, an additional advantage of prechemotherapy axillary biopsy is the availability of untreated, metastatic tumor tissue for banking and correlative testing. As tailored therapy becomes the buzzword for therapeutics in all arenas, the availability of tumor for appropriate studies may be an invaluable resource for the patients involved. Dr Batsis and colleagues do raise an extremely valid point regarding the time and cost efficacy of prechemotherapy axillary staging. Clearly, there are additional temporal and financial costs associated with both ultrasound-guided FNA and sentinel node biopsy. The Comprehensive Breast Program at Moffitt Cancer Center in conjunction with a health care economist has an ongoing study examining these exact issues. We hope to have preliminary results from those analyses in the coming year.