Treatment patterns and clinical outcomes of patients with HER2-positive T1micN0 breast cancer: a single-center analysis

We conducted a retrospective analysis of 213 patients with HER2+ T1micN0 breast cancer. Patients with ≥5 foci of microinvasion received more aggressive treatment with higher rates of sentinel lymph node biopsy and adjuvant chemotherapy/HER2-targeted therapy (CT/H2TT) than patients with 1-4 foci. We did not detect significant differences in invasive disease-free survival between patients with 1-4 and ≥5 foci, or between patients with ≥5 foci who did and did not receive adjuvant CT/H2TT.