Real-world outcomes of early-stage HER2-positive breast cancer patients treated with adjuvant paclitaxel and trastuzumab.

This retrospective study evaluated 276 patients with early-stage HER2-positive breast cancer, mostly hormone receptor-positive and grade 3 tumors, treated with the weekly paclitaxel and trastuzumab (APT) regimen.

The majority of patients had tumors ≤2 cm and no nodal involvement, with most classified as stage IA.

At a median follow-up of 4.4 years, outcomes were as follows:

• 3-year recurrence-free survival: 97.3%
• Distant relapse-free survival: 98.2%
• Invasive breast cancer-free survival: 97.1%

Outcomes were excellent for stage IA patients but significantly worse for stages IB and IIA.

This highlights the need for caution when applying APT in higher stage early HER2-positive breast cancer.