Abstract PO4-03-12: De-escalating treatment with neoadjuvant chemotherapy in early triple-negative breast cancer

Abstract

Abstract Neoadjuvant chemotherapy (NAT) is a standard treatment in early triple-negative breast cancer, but the regimen and duration of this treatment are controversial. We analyze a cohort of early triple negative breast cancer treated with NAT with different schemas to determine its efficacy. 272 patients treated with NAT since 2001 to 2020 were selected. The median age of the group was 57 years (27-85), initial size 30 mm (9-122) and Ki67 expression was 60 (7-100). 107 patients (39.3%) had histologically confirmed initial axillary involvement and the regimens of chemotherapy used were carboplatin AUC 5 + weekly paclitaxel (80 mg/m2) x 4 cycles in 56 cases (21%) (SCHEME A), same scheme followed by 4 cycles of adriamycin 50 mg/m2 + cyclophosphamide 500 mg/m2 in 85 cases (31%) (SCHEME B), Adriamycin 50 mg/m2 + cyclophosphamide 500 mg/m2 × 4 cicles in 44 (16%) (SCHEME C) and Adriamycin 50 mg/m2 + cyclophosphamide 500 mg/m2 × 4 cicles followed by docetaxel 100 mg/m2 × 4 cicles in 87 (32%) (SCHEME D). We achieved a 51% of pathologic complete response (pCR),and a total of 24% of recurrences. The proportion of PCR and recurrence according to the different schemes is represented in the following table. The clinical factors associated with recurrence were the initial size (OR 8.6), the initial axillary involvement (OR 4.21) and the absence of pCR (OR 8.14), and for patients with pCR it was only the initial axillary involvement (OR 3.4). Patients that received schema A in NAT only presented a total of 5% of recurrence (3/56), only in patients with initial axillary involvement. The NAT schema with carboplatin AUC 5 + weekly paclitaxel (80 mg/m2) x 4 cycles is safe in patients without initial nodal involvement with high pathologic complete response (62%) and lower recurrence rate (9% in nonPCR and 3% in pCR). Therefore, it could be considered as a standard scheme of neoadjuvant chemotherapy for patients without axillary involvement. Table. SCHEMA A (20%) B (31%) C (16%) D (32%) Pcr 62% 63% 41% 37% Recurrence in pCR 3% 7% 16% 9% Recurrence in nonpCR 9% 16% 50% 63% Citation Format: Serafin Morales Murillo, Ariadna Gasol Cudós, Noemí Tuset Der-Abrain. De-escalating treatment with neoadjuvant chemotherapy in early triple-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-03-12.