Investigating the Efficacy and Safety of a Dose-Dense Paclitaxel, Cyclophosphamide With Trastuzumab in Stage I-II Human Epidermal Growth Factor Receptor 2 (HER2) Positive Breast Cancer

Background

The evolution of systemic therapies has improved outcomes for patients with human epidermal growth factor receptor 2 positive (HER2+) breast cancer. Nonetheless, the tolerability and safety profile of systemic therapies represent an area for further improvement. Here we report the results of a phase 2 trial evaluating a nonanthracycline, nonplatinum adjuvant treatment regimen for patients following initial surgical resection.

Methods

We enrolled patients with stage I or II HER2+ breast cancer who underwent upfront surgery to receive adjuvant treatment with 6 cycles of dose-dense Paclitaxel, cyclophosphamide and Trastuzumab (PC-H) every 2 weeks, followed by 13 cycles of maintenance trastuzumab every 3 weeks to complete 52 weeks of treatment (compromising 19 cycles). The primary objective was to determine the safety and feasibility of adjuvant PC-H, measured by the completion rate frequency and the grade of adverse events, using National Cancer Institute Common Terminology Criteria. The secondary objective was to estimate relapse-free survival and overall survival.

Results

Between 2010 and 2019, a total of 39 patients were enrolled. Of those, 34 patients (87.18%) completed the planned treatment. Severe adverse events of grade 3 or 4 occurred in 27 patients (69.23%), including 3 patients (7.69%) with grade 3-4 decrease in ejection fraction. At median follow up of 5.6 years, all 39 patients were alive. The 5-year relapse-free survival was 94.30% (95% CI: 75.3-100).

Conclusions

PC-H demonstrated overall safety and efficacy, yielding high rates of relapse-free survival among patients with early stage (HER2+) breast cancer.