Response to neoadjuvant chemotherapy in the breast predicts axillary nodal status

We hypothesize that the diminishing role of axillary node dissection (ALND) in early stage breast cancer could be further reduced in patients with advanced disease depending on the response to neoadjuvant chemotherapy (NC). We reviewed records of patients managed with NC and recorded demographics, tumor characteristics, pre/postoperative axillary nodal status, and NC response. We define a response to NC as follows: T2 tumors at least a 50 per cent reduction in the product of the length and width of the tumor and in T3-4 tumors a reduction in tumor size to less than 2 cm. We defined a negative axillary nodal status as either a negative sentinel node biopsy before or after NC or a negative ALND. We defined a positive axillary nodal status as clinical persistence of nodal disease despite NC or involved nodes determined by ALND. Fisher's exact test was used to evaluate the association between response to NC and nodal status. Over the past 4 years, 35 patients have completed NC and surgical treatment including lymph node assessment. Sixteen cancers demonstrated a response to NC and two (12.5%) had positive lymph nodes. Nineteen cancers failed to respond to NC and 13 (68.4%) had involved lymph nodes. Fisher's exact test shows a strong association between NC response and nodal status (two-tailed P value 0.0016). Patients with advanced locoregional breast cancer that respond to NC are unlikely to benefit from ALND. If this study's findings are confirmed in larger trials, ALND could be limited to patients with advanced locoregional breast cancer unresponsive to NC.