ADJUVANT PACLITAXEL-HERCEPTIN FOR SMALL HER2+ BREAST CANCER

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 supp