Background: Neoadjuvant systemic therapy (NST) increases the frequency of breast-conserving therapy (BCT) in stage II-III breast cancer, but there is little data on how often it converts patients (pts) from BCT-ineligible (BCT-I) to BCT-eligible (BCT-E) and on the impact of other factors on surgical choices. We collected surgical assessment and management data from an international randomized trial of NST in triple-negative breast cancer (TNBC). Methods: Women with operable TNBC were randomized to veliparib (V) with carboplatin (C) and paclitaxel (P), placebo with C and P or placebo with P followed by doxorubicin and cyclophosphamide. The surgeons assessed BCT candidacy by clinico-radiographic criteria before and after NST; surgical management was at surgeon and patient discretion. We assessed interactions between BCT eligibility pre- and post-NST, germline BRCA mutation (gBRCA) status, continent of treatment and achievement of pathologic complete response(pCR) and percentage of pts who underwent BCT versus mastectomy. Results: Pre- and post-NST surgical assessments were available for 604 pts who underwent surgery. BCT rates are listed in the Table. The BCT rate was 68% among pts deemed BCT-E after NST. pCR rates were identical between BCT-E pts who chose BCT (55%) vs. mastectomy (53%). Of 141 pts deemed BCT-I at baseline, 75 (53%) converted to BCT-E but only 42 (56%) of these opted for BCT. pCR rates were 49% in BCT-E converts vs. 36% in those remained BCT-I. gBRCA pts (n = 84) were less likely to choose BCT even if they were BCT-E. Pts treated in North America (NA) were less likely to choose BCT (55% vs. 80% for Europe and Asia P<0.0001) even among non-gBRCA considered BCT-E post-NST (61% vs. 85% P<0.0001). Conclusions: This largest prospective analysis of the impact of NST in TNBC demonstrates a conversion rate from BCT-I to BCT-E of 53%. BCT rates were lower in pts with gBRCA; the much higher mastectomy rate among BCT-E pts in NA merits investigation. Clinical trial information: NCT02032277