Pathologic complete response (pCR) to neoadjuvant treatment (NAT) with carboplatin, nab-paclitaxel and anthracycline in early and locally advanced triple-negative breast cancer (TNBC).

Abstract

e12608 Background: Achieving a pCR (absence of residual invasive disease in breast and measurable disease in any of the axillary nodes sampled, ypT0/is and ypN0) after NAT correlates with improved survival. TNBC phenotype have a poor prognosis. However, it is associated with higher NAT response rates. With traditional schemes based on anthracyclines and taxanes, pCR rates of around 25-40% are obtained. Different schemes have been studied providing an increase in pCR such as using nab-paclitaxel, platinum salts, bevacizumab or dose dense (dd) anthracyclines. The purpose of the present study is to explore feasibility, toxicity and pCR of new aproach with carboplatine, nab-paclitaxel and antracycline in TNBC. Methods: Retrospective study with early and locally advanced TNBC pts, ECOG 0-1, without contraindications to antracyclines, were included. Treatment consisted of carboplatine AUC2 with nab-paclitaxel 80 mg/m2 i.v. weekly for 12 doses followed by epirubicin 90 mg/m2 (elderly pts recieved at 75 mg/m2) with cyclophosphamide 600 mg/m2 i.v., every 2 weeks (dd) or 3 weeks (if pts had G3-4 toxicity) for 4 doses. G-CSF support was allowed in pts with neutropenia G3-4. Pts with residual disease after NAT were offered capecitabine as adjuvant treatment. The primary endpoint was pCR. Results: From 02/2018 to 06/2022, 96 pts was included. Median age was 53 years (27-78). Clinical stage was I in 16 pts, II in 50 pts and III in 30 pts (N+ in 40'6%). 98% pts had tumours with a Ki67 20% or higher. 36’5% pts was premenopausal. 10 pts were germline BRCA mutated (8/10 gBRCA1, 2/10 gBRCA2) 50/96 pts (55’2%) had dd epirubicin-cyclophospamide (EC) and 44’8% pts recieved EC every 3 weeks (for G3 adverse events (AE)). pCR in pts who had dd treatment was 65’4% and 40’9% in pts with EC non-dd (p 0’016). 89’9% pts with residual disease completed adjuvant treatment with 8 cycles of capecitabine. 53/96 pts had an AE related with NAT. Neutropenia G3-4 (45’5% pts, all of them recieved dd treatment) and any grade of alopecia and mucositis (60% and 25% respectively) were the most frecuent AE reported. Pts with neutropenia G3-4 on blood test recieved G-CSF in subsequent cycles with resolution of haematological AE. All pts with dd treatment recieved G-CSF. One patient had a disease progression by radiological evaluation during the treatment. During follow-up 9 pts relapsed (1 had a pCR with NAT) and 5 pts died for progression disease. Conclusions: NAT on TNBC pts with carboplatine, nab-paclitaxel and antracycline dd is a feasible, safe and highly effective option. Even though survival analysis is not yet mature in our study, pCR has been shown to be a surrogate for overall survival. The excellent results obtained with this scheme, make it a good treatment option and could be an alternative to pembrolizumab (Keynote-522) in pts with autoinmmune diseases or immune-AE due to similar pCR.