277P - Long term follow-up of neoadjuvant chemotherapy with or without anthracyclines in the presence of trastuzumab in patients with HER2-positive breast cancer

Background

Because Pertuzumab hasn't been approved in China until 2020y, trastuzumab has been standard neoadjuvant treatment for HER2-positive breast cancer. But we don't know which is the optimal chemotherapy in the trastuzumab-based HER2-blockade. We designed this clinical trial to compare efficacy and safety between anthracycline and carboplatin in combination with docetaxel and trastuzumab as neoadjuvant therapy. Now we reported the long-term follow-up data.

Methods

From Apr, 2013 to Apr, 2019, 128 patients were enrolled. 63 patients were randomly assigned to the ATH-TH (doxorubicin/docetaxel/trastuzumab) group and 65 to the TCH (docetaxel/carboplatin/trastuzumab)group. The treatment plan is showed as following, 1. TCH group: Trastuzumab combined with carboplatin and docetaxel, total 6 cycles; 2. ATH-TH group: Trastuzumab combined with doxorubicin and docetaxel 4 cycles, followed by Trastuzumab plus docetaxel 4 cycles. Primary endpoint was pCR (ypT0/is/ypN0). Second endpoints included safety, event-free and overall survial (EFS and OS).

Results

Baseline Patients' characteristics were well balanced between ATH-TH group and TCH group: median age 50y/48y, hormone receptor positive 44.4% vs 46.2%, Ⅰ-ⅢA stage 79.4% VS 86.2%, IIIB-IIIC stage 20.6% VS 13.8%. The pCR rate was no significant difference (P=0.592) in ATH-TH 54.0% (95% CI:41.3%-66.6%) and TCH group 49.2% (95% CI :36.7%-61.7%). Seven-year EFS estimates were 85.6% for ATH-TH and 88.4% for TCH (p=0.767, HR=1.17, 95% CI: 0.42-3.21). Seven-year OS estimates were 94.4% for ATH-TH and 94.4%for TCH (p=0.691, HR=1.35, 95% CI: 0.31-5.90). Patients who achieved a pCR had improved EFS (p<0.001) and OS (p=0.003) compared with those who did not. The most common adverse events were hematologic toxicities. ATH-TH group had higher 3/4 grade leukocyte decrease rates than TCH group (91.9% VS 44.6%, p<0.001), ATH-TH group had more FN than (32.8% VS 3.1%, p<0.001).

Conclusions

This is the first prospective randomised trial comparing neoadjuvant therapy regimen ATH-TH with TCH in HER2-positive breast cancer of pCR and long-term survival data. We acquired similar pCR rate, seven-year EFS and OS but less toxicity in TCH group compared with ATH-TH.

Clinical trial identification

NCT02510781.

Editorial acknowledgement

Legal entity responsible for the study

The Fifth Medical Center of Chinese PLA General Hospital.

Funding

Beijing Municipal Natural Science Foundation.

Disclosure

All authors have declared no conflicts of interest.