Neoadjuvant Chemotherapy Regimens for Early Breast Cancer

General Principles of Neoadjuvant Therapy

The American Society of Clinical Oncology recommends neoadjuvant therapy for stage II-III breast cancer, particularly for HER2-positive and triple-negative subtypes, as it provides effective systemic therapy, improves surgical options, and allows for tailoring of adjuvant treatment based on response 2, 3
The same chemotherapy regimens used in the adjuvant setting are recommended for neoadjuvant treatment 4

For stage II-III HER2-positive breast cancer, the National Comprehensive Cancer Network recommends neoadjuvant chemotherapy with dual HER2 blockade (trastuzumab and pertuzumab) 1, 2
Chemotherapy backbone options include anthracycline-taxane sequential regimens 2, 5 and taxane-carboplatin combinations (anthracycline-free) which show similar outcomes with improved cardiac safety 2, 3
Dual HER2 blockade with trastuzumab-pertuzumab achieves higher pathologic complete response (pCR) rates than trastuzumab alone 1, 5
Post-neoadjuvant treatment should be based on response, with continuation of anti-HER2 therapy to complete 1 year of treatment for patients achieving pCR 2, 5, and switch to T-DM1 for 14 cycles for patients with residual disease 1, 2, 5

The European Society for Medical Oncology recommends neoadjuvant therapy as the standard approach for stage II-III TNBC 2, 3
Preferred regimen includes sequential therapy with either anthracycline-based regimens followed by taxanes, or taxanes with carboplatin followed by anthracycline-based therapy 2, 3
Addition of pembrolizumab to chemotherapy is recommended based on the KN522 trial 2, 3

The American College of Surgeons recommends neoadjuvant chemotherapy to effectively downstage HR-positive/HER2-negative cancers for surgical purposes, although pCR is less common 2, 3
For patients with low-risk genomic signatures or those who are not candidates for chemotherapy, neoadjuvant endocrine therapy for at least 6 months is an option 2, 6
Anthracycline-taxane based regimens are recommended for patients requiring chemotherapy 1, 7

Anthracycline-taxane sequential regimens, such as doxorubicin-cyclophosphamide (AC) × 4 followed by taxane × 4, are recommended 7, 8
Non-anthracycline regimens, such as docetaxel-cyclophosphamide × 4, are alternative options with improved DFS and OS 7, 8
Taxane-carboplatin combinations are recommended for HER2-positive disease 2, 5

For HER2-positive disease with residual tumor, switch to T-DM1 for 14 cycles 1, 2, 5
For TNBC with residual disease after standard neoadjuvant chemotherapy, consider adjuvant capecitabine 3, 4
For HR-positive disease, adjuvant endocrine therapy is recommended based on menopausal status 1, 9

Regular cardiac monitoring is mandatory before and during trastuzumab treatment due to potential cardiotoxicity 4
Cumulative dose limits should be observed for patients receiving anthracyclines (doxorubicin ≤240 mg/m² or epirubicin ≤720 mg/m²) 7, 8