35P - Pathological response to weekly nabpaclitaxel and carboplatin followed by anthracycline regimen in triple negative breast cancer

Background

Pathological complete response (pCR) is considered a potential surrogate marker for survival in triple negative breast cancer (TNBC), thus attracting strategies to achieve higher pCR. Addition of carboplatin to standard neoadjuvant chemotherapy regimen has been seen to increase pCR.

Methods

We aimed to evaluate efficacy of nab paclitaxel and carboplatin followed by dose dense anthracycline regimen by pCR in women with locally advanced tnbc. Patients with confirmed stage 2 or 3 were included. Hormone receptor and her 2 neu receptor status was confirmed by IHC and/or FISH. Patients received 12 weekly nab paclitaxel 125 mg/m2 plus carboplatin AUC 2 followed by dose dense doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 for 4 cycles and subsequent surgery. pCR was defined as absence of any disease in breast and axilla on surgical specimen. Secondary end points were breast conservation rates, progression free survival and toxicities.

Results

35 patients with confirmed stage 2 (20%) and stage 3 (80%) were treated between January 2017 and December 2020.The median age of patients was 48.7 years (26 – 71). pCR was achieved in 62.8 % (22) and remaining patients had partial response 34.2% (12). One patient showed stable disease on pathological specimen. Breast conservation surgery (BCS) was possible in 60 % (21). Of those who achieved pCR, 68 % (15) underwent BCS. Grade 3/4 toxicities were fatigue 2.8 % (1), thrombocytopenia 8.5 % (3), nausea/vomiting 2.8 % (1), peripheral neuropathy 2.8 %(1), febrile neutropenia 17 % (6) and anemia 14.2% (5). Hematological toxicity was tackled with reduction of carboplatin dose to AUC 1.5. Dose modifications were done in 63 % of patients. Anemia (74.2%), neutropenia (80%) and thrombocytopenia (71.4%) were most common all grade toxicities. After a median follow up of 25 months, median progression free survival was 68 % as per Kaplan-Meier analysis.

Conclusions

Nab paclitaxel and carboplatin followed by anthracycline regimen as neo adjuvant regimen led to impressive pCR rate of 62.8% in our study. Regimen was tolerated well with necessary dose adjustments showing good response rates with a trend towards increased progression free survival.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.