Staging of Invasive Ductal Carcinoma
For invasive ductal carcinoma, staging requires bilateral mammography, pathologic assessment with hormone receptor and HER2 status, sentinel lymph node biopsy for axillary evaluation, and application of the TNM staging system, with the extent of additional imaging determined by clinical stage. 1
Initial Clinical Assessment
The clinical evaluation must document specific tumor parameters including:
- Tumor size, location, and relationship to the nipple-areolar complex 1
- Axillary examination for palpable lymphadenopathy 1
- Contralateral breast assessment to identify synchronous disease 1
- Evaluation of systemic symptoms suggesting metastatic disease 1
Required Imaging Studies
All Patients
- Bilateral mammography within 3 months to establish disease extent and rule out multicentric involvement 1
- Breast ultrasound as clinically warranted to characterize lesions 1
Stage-Specific Imaging
- Stage I-II disease: Streamlined evaluation with history, physical examination, laboratory studies, bilateral mammography, and pathologic assessment only—additional imaging indicated only for symptoms or abnormal findings 1
- Stage III disease: All baseline studies plus chest imaging (required), with optional bone scan and abdominal imaging, and PET/CT reserved for equivocal findings 1
Pathologic Assessment Requirements
Every invasive ductal carcinoma requires:
- Histologic confirmation with WHO classification 1
- Tumor grade determination 1
- Hormone receptor status (ER/PR) 1, 2
- HER2 status 1, 2
- Lymphovascular invasion assessment (associated with increased recurrence risk) 1
- Surgical margin assessment with proper specimen orientation 1
Axillary Staging Protocol
Sentinel lymph node biopsy is the standard approach for axillary staging in invasive carcinoma 1, 3. The number of positive nodes significantly impacts prognosis and guides adjuvant therapy decisions 1. This differs from DCIS, where approximately 25% of cases are upstaged to invasive disease at surgery, making selective use of sentinel node biopsy important to avoid overtreatment 4.
Required Laboratory Studies
Baseline studies include:
- Complete blood count with platelets 1
- Liver function tests 1
- Alkaline phosphatase 1
- Routine chemistry panel 1
TNM Staging Application
Apply the American Joint Committee on Cancer TNM staging system, incorporating:
This determines the final stage and guides treatment decisions 1.
Critical Staging Pitfalls to Avoid
Over-imaging Early-Stage Disease
Avoid unnecessary imaging in stage I-II disease, as this leads to false positives, unnecessary biopsies, and patient anxiety 1. The evidence clearly shows that extensive staging workup is not indicated for early-stage disease without symptoms or abnormal findings 1.
Inadequate Preoperative Assessment
- Failure to obtain bilateral mammography can miss synchronous contralateral disease 1
- Inadequate preoperative imaging results in incomplete tumor excision 1, 3
- Improper specimen orientation makes margin assessment difficult 3
Specimen Handling
Specimen radiography should be performed intraoperatively to confirm removal of mammographic abnormalities 3. Proper orientation is critical to ensure negative margins while avoiding excess tissue removal 3.
Risk Stratification Factors
For treatment planning and prognosis, consider: