1007 Background: Neoadjuvant therapy (NAT) improves breast conserving therapy (BCT) rates, but the extent by tumor subtype is unknown. To quantify this effect for triple-negative breast cancer (TNBC) and HER2-positive breast cancer (HER2+ BC), we reviewed surgical outcomes from CALGB 40603, a randomized phase II trial of weekly paclitaxel (P) +/- carboplatin (Cb) followed by doxorubicin + cyclophosphamide (AC) +/- bevacizumab (B) for stage (stg) II-III TNBC, and CALGB 40601, a randomized phase III trial of paclitaxel (P)+ HER2 blockade with trastuzumab (P+H), lapatinib (P+L) or both (P+H+L) for stg II-III HER2+ BC, by requiring surgeons to prospectively evaluate BCT eligibility before and after NAT. Methods: Patients (pts) with stg II-III TNBC (n = 404) were randomized in CALGB 40603. Pts with stg II-III HER2+ BC (n = 292) were randomized in CALGB 40601. The treating surgeon assessed BCT candidacy based on clinico-radiographic criteria before and after NAT. Subsequent surgical management was at surgeon an...