Abstract P5-16-19: Evaluation of weekly paclitaxel plus carboplatin followed by anthracycline chemotherapy on the neoadjuvant treatment of patients with triple-negative breast cancer
Authors: Castrellon AB , Velez M , Blaya M , Barnick S , Dumais K , LeCroy N 
Published: March 2017

Background

Triple negative breast cancer (TNBC) accounts for 15 to 20 % of the invasive breast cancers. Pathological complete response (pCR) in this subgroup of breast cancer is associated with improved long term event free survival. Results from previous studies indicate that the addition of carboplatinum (Cb) to standard neoadjuvant anthracycline-taxane chemotherapy results in an increase in pCR. One of the investigational arms of the CALGB 40603 tested paclitaxel 80 mg/m2 once a week (wP) for 12 weeks with concurrent Cb (area under curve 6) once every 3 weeks for four cycles, followed by doxorubicin plus cyclophosphamide once every 2 weeks (ddAC) for four cycles. Although effective this regimen has been difficult to reproduce in the daily practice. The purpose of this study was to evaluate the effectiveness and tolerability of wP in combination with weekly Cb (wP+wCb) area under curve 2 (AUC=2) followed by anthracycline chemotherapy.

Methodology

The electronic medical record system was used to identify female patients 18 years of age or older with clinical stage I-III (TNBC) who received neoadjuvant chemotherapy of wP+wCb (AUC=2) before or after anthracycline chemotherapy between January 1, 2014 and March 1, 2016. The primary outcome was to evaluate the tolerability of fractionating carboplatin to weekly infusions in combination with weekly paclitaxel. The secondary outcomes included the pCR (no evidence of invasive tumor in the breast and axilla), Residual Cancer Burden (RCB), the number of cycles received in each chemotherapy regimen and frequency of chemotherapy related toxicities.

Results:

For the 32 eligible patients, median age: 51 years, Stage I: 6%, Stage II: 68%, Stage: III 26%, germline BRCA mutation: 10%, KI 67 &gt; 75% : 72%. 93% of the patients received 11-12 cycles of wP+wCb and 83% received all 4 planned cycles of anthracycline chemotherapy. 83% of patients completed all planned therapy. pCR and RCB 0/1 rates were 60% (19/32) and 75% (24/32) respectively. RCB 2: 22% (7/32), RCB 3: 3% (1/32). 93% of the patients experienced grade 3 neutropenia during wP+wCb requiring GCSF, Grade 3 anemia was seen in 15 % (5/32) and Grade 3 thrombocytopenia was seen in 18 % (6/32).

Conclusion:

The combination of neoadjuvant chemotherapy with wP+wCb before or after anthracycline chemotherapy was well tolerated among patients with TNBC as demonstrated by the fact that most participants were able to receive all planned 12 cycles of wP+ wCb and all 4 cycles of anthracycline chemotherapy. Complete pathologic response rates were comparable to historically seen. The findings support the continued use of this treatment modality in the general practice.

Citation Format: Castrellon AB, Velez M, Blaya M, Barnick S, Dumais K, LeCroy N. Evaluation of weekly paclitaxel plus carboplatin followed by anthracycline chemotherapy on the neoadjuvant treatment of patients with triple-negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-19.