Follow-up of Adjuvant Paclitaxel and Trastuzumab in Small HER2-Positive Breast Tumors
As reported in the Journal of Clinical Oncology by Tolaney et al, 7-year follow-up of the phase II Adjuvant Paclitaxel and Trastuzumab trial showed that adjuvant paclitaxel and trastuzumab were associated with “excellent” outcomes in women with small, node-negative HER2-positive breast cancer.
In the multicenter trial, 406 eligible patients with HER2-positive breast cancer with tumors no larger than 3 cm and negative nodes were enrolled from October 2007 to September 2010. They were treated with adjuvant paclitaxel (80 mg/m2) and weekly trastuzumab for 12 weeks followed by single-agent trastuzumab every 3 weeks for 9 months.
The previously reported primary analysis of the trial showed a 3-year disease-free survival of 98.7% with the regimen. The current analysis presents outcomes at the 7-year follow-up.
7-Year Outcomes
After a median follow-up of 6.5 years, there were 23 disease-free survival events. Rates at 7 years were 93% for disease-free survival (with 4 distant recurrences, or 1.0%), 95% for overall survival, and 97.5% for recurrence-free interval (which included distant recurrence, death from breast cancer, and invasive locoregional recurrence).
PAM50 analysis in 278 patients showed that most tumors were HER2-enriched (66%), followed by luminal B (14%), luminal A (13%), and basal-like (8%). Genotyping in 230 patients identified one single nucleotide polymorphism (rs3012437) as associated with an increased risk of paclitaxel-associated peripheral neuropathy in patients with grade ≥ 2 or greater paclitaxel-associated peripheral neuropathy (10.4%) after adjustment for age and body surface area (odds ratio = 2.1, P = .024).
The investigators concluded, “With longer follow-up, adjuvant paclitaxel and trastuzumab is associated with excellent long-term outcomes. Distribution of PAM50 intrinsic subtypes in small HER2-positive [breast] tumors is similar to that previously reported for larger tumors.”
Sara M. Tolaney, MD, MPH, of Dana-Farber Cancer Institute, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by Genentech. The study authors’ full disclosures can be found at jco.ascopubs.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
