Definition of Locally Advanced Breast Cancer
Locally advanced breast cancer (LABC) is a subset of invasive breast cancer where clinical and radiographic evaluation documents advanced disease confined to the breast and regional lymph nodes, corresponding to AJCC Stage III disease, without evidence of distant metastases. 1
Clinical Staging Classification
LABC is represented by the Stage III category in the AJCC clinical staging system and can be further subdivided based on operability 1:
Operable LABC
- Clinical Stage T3N1M0 - Generally considered operable with reasonable likelihood of achieving pathologically negative margins and long-term local control 1
Inoperable LABC
The following presentations are considered inoperable at diagnosis 1:
- Clinical Stage IIIA (except T3N1M0) - includes TanyN2M0 disease
- Clinical Stage IIIB - includes tumors with skin or chest wall involvement
- Clinical Stage IIIC - extensive regional lymph node involvement
- Inflammatory breast cancer
Key Defining Features
LABC encompasses breast cancers with 2, 3:
- Large primary tumors (typically >5 cm)
- Skin involvement of the breast
- Chest wall involvement (underlying muscle infiltration)
- Extensive regional lymph node involvement
- Disease that remains confined to the breast and regional lymph nodes without distant metastases
Important Clinical Distinction
The critical distinction is that LABC represents advanced locoregional disease that is still potentially curable with multimodal therapy (surgery, radiation, and systemic treatment), unlike metastatic disease 4, 5, 6. The initial surgical approach for inoperable LABC is unlikely to remove all disease or provide long-term local control without neoadjuvant systemic therapy first 1.
Multidisciplinary Evaluation
Determination of operability requires evaluation by a multidisciplinary team to assess whether an initial surgical approach can achieve pathologically negative margins and provide long-term local control 1. This assessment guides whether patients receive upfront surgery (operable) or neoadjuvant systemic therapy first (inoperable).