In an analysis reported in The Lancet Oncology, Sara M. Tolaney, MD, MPH, and colleagues described 10-year survival outcomes from the phase II APT trial assessing adjuvant paclitaxel/trastuzumab in patients with node-negative, HER2-positive breast cancer.
Study Details
The U.S. multicenter trial included a total of 406 patients with small (≤ 3 cm) node-negative disease enrolled between October 2007 and September 2020. They received adjuvant treatment with weekly paclitaxel at 80 mg/m² and trastuzumab at a loading dose of 4 mg/kg followed by 2 mg/kg weekly for 12 weeks, followed by trastuzumab weekly at 2 mg/kg or once every 3 weeks at 6 mg/kg for 40 weeks to complete a full year of treatment with trastuzumab. The primary endpoint was 3-year invasive disease–free survival.
Sara M. Tolaney, MD, MPH
Key Findings
Median follow-up was 10.8 years (interquartile range = 7.1–11.4 years).
A total of 31 invasive disease–free survival events were observed: 6 (19.4%) were locoregional ipsilateral recurrences, 9 (29.0%) were new contralateral breast cancers, 6 (19.4%) were distant recurrences, and 10 (32.3%) were all-cause deaths.
Ten-year invasive disease–free survival was 91.3% (95% confidence interval [CI] = 88.3%–94.4%), and the 10-year recurrence-free interval (freedom from distant recurrence, death from breast cancer, and invasive locoregional recurrence) was 96.3% (95% CI = 94.3%–98.3%).
Ten-year overall survival was 94.3% (95% CI = 91.8%–96.8%), and 10-year breast cancer–specific survival was 98.8% (95% CI = 97.6%–100%).
In an exploratory analysis using the HER2DX genomic tool, the HER2DX risk score as a continuous variable was significantly associated with invasive disease–free survival (hazard ratio [HR] per 10-unit increment = 1.24, 95% CI = 1.00–1.52, P = .047) and recurrence-free interval (HR per 10-unit increment = 1.45, 95% CI = 1.09–1.93, P = .011).
The investigators concluded, “Adjuvant paclitaxel and trastuzumab is a reasonable treatment standard for patients with small, node-negative, HER2-positive breast cancer. The HER2DX genomic tool might help to refine the prognosis for this population.”
Dr. Tolaney, of the Department of Medical Oncology, Dana-Farber Cancer Institute, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by Genentech. For full disclosures of the study authors, visit thelancet.com.
