Al‐Hilli, Zahraa

ObjectivesWe investigated the impact of neoadjuvant chemotherapy (NAC) on axillary disease burden in clinically node‐negative (cN0) HER‐2 positive breast cancer patients.MethodsWe studied 215 cN0 patients with HER‐2 positive tumors. Multivariable logistic regression was used to compare NAC versus primary surgery (PS) with respect to outcome of pathologic nodal disease.ResultsOf 215 patients, 42 (20%) received NAC. NAC use correlated with higher clinical T stage (P < 0.0001) and younger age (P = 0.03) with no difference in ER/PR status or tumor grade. Despite higher clinical T stage in the NAC group, rate of pathologic positive axillary nodes was non‐significantly lower (NAC 5/42 = 11.9%, PS 27/173 = 15.6%, P = 0.54). In multivariable analysis, after adjustment for confounders including clinical T stage, age, and multifocal/multicentric disease, NAC showed significant reduction in odds of pathologic nodal disease (OR 0.26, 95%CI:0.06–0.90, P = 0.03). Further, among those with pathologic nodal disease, the number of positive nodes was lower after NAC (adjusted P = 0.03). Extranodal extension was present in 8/27 (30%) PS patients vs. 1/5 (20%) of the NAC patients (adjusted P = 0.36).ConclusionNAC in cN0 HER‐2 positive breast cancers reduces the rate of pathologic node‐positive disease at operation and nodal disease burden and may decrease the need for axillary node dissection. J. Surg. Oncol. 2015; 112:453–457. © 2015 Wiley Periodicals, Inc.