Patients must meet one of the following criteria: N stage ≥1; T stage ≥2; did not achieve pathological complete response (pCR) after neoadjuvant therapy; had pCR after neoadjuvant therapy but with tumor size ≥ 5cm or N stage ≥2; or tumor size less than 2cm but with high Ki67; histologic grade 3 or with lymph node micrometastasis.
This trial is a multicenter, open-label, phase II trial conducted at 23 centers in China. High-risk HER2 positive patients receive pyrotinib 400mg/day for one year or half year for extented adjuvant therapy.