Patients
with HER2-positive breast cancer do not achieve pathological complete remission (pCR) after neoadjuvant therapy, and the following aspects can be considered for follow-up treatment: Adjuvant chemotherapy • For patients who have used a full course of neoadjuvant therapy and have not reached pCR, some may need to supplement a certain cycle of adjuvant chemotherapy. The specific plan should be determined according to the medication of neoadjuvant chemotherapy and the tolerance of patients. Anti-HER2 targeted therapy • Continued use of trastuzumab: If trastuzumab is used in the neoadjuvant phase, the standard course of 1 year is usually completed as planned before pCR to continue to inhibit the HER2 signaling pathway to play an anti-tumor role. • Intensive targeted therapy: Other anti-HER2 targeted drugs may be considered to be switched or added, such as: • T-DM1 (Enmetrezumab): Several studies have shown that the subsequent use of T-DM1 can further reduce the risk of recurrence and improve the disease-free survival of HER2-positive patients who have not reached pCR after neoadjuvant therapy compared with the continued use of trastuzumab. The general dosage is 3.6mg/kg, once every 3 weeks. • Pertuzumab plus trastuzumab: Dual-targeted therapy with pertuzumab plus trastuzumab has also been shown to further improve outcomes in these patients compared to trastuzumab alone, often with trastuzumab (8 mg/kg loading dose followed by 6 mg/kg maintenance dose every 3 weeks) and pertuzumab (840 mg loading dose, Followed by a maintenance dose of 420 mg every 3 weeks). • DS-8201 (detrastuzumab): a new anti-HER2 targeted drug, which has shown good efficacy in patients who have not reached pCR after neoadjuvant therapy in related studies, with a generally recommended dose of 5.4 mg/kg once every 3 weeks. Endocrine therapy (for hormone receptor-positive patients) • If the patient is accompanied by hormone receptor-positive, after completing the above anti-HER2 targeted therapy and necessary chemotherapy, appropriate endocrine therapy should be given according to the menstrual status of the patient, such as tamoxifen before menopause and aromatase inhibitors after menopause, to further reduce the risk of recurrence. Radiotherapy • For some patients with high risk factors of local recurrence, such as axillary lymph node metastasis, adjuvant radiotherapy may be needed after operation to reduce the local recurrence rate. Specific follow-up treatment plans need to be formulated by multidisciplinary teams (including oncology, breast surgery, radiotherapy, pathology, etc.) After comprehensive assessment of the patient’s individual conditions (such as age, physical condition, early treatment response, tumor staging, etc.).
