What is the process for staging breast cancer in an adult female patient with no significant underlying medical conditions?

How to Stage Breast Cancer

Breast cancer staging follows a systematic, risk-stratified approach using the TNM classification system, with the extent of staging investigations determined by clinical stage and risk factors rather than applying comprehensive imaging to all patients. 1, 2

Initial Clinical and Pathological Assessment (All Patients)

Patient History and Physical Examination

• Obtain complete personal medical history, family history of breast/ovarian cancers, and assess menopausal status (measure serum estradiol and FSH if uncertain) 1, 2
• Perform bimanual palpation of both breasts and locoregional lymph nodes (axillary, supraclavicular) 1
• Document performance status and any symptoms suggesting metastatic disease 1, 2

Laboratory Studies

• Complete blood count, liver and renal function tests, alkaline phosphatase, and calcium levels 1, 2

Imaging for Local Disease Assessment

• Bilateral mammography and ultrasound of breasts and regional lymph nodes 1, 2
• MRI is not routine but may be considered for dense breast tissue in young women, BRCA-associated cancers, or when multiple tumor foci are suspected 1

Tissue Diagnosis and Biomarker Assessment

• Core needle biopsy (preferably ultrasound or stereotactic-guided) with pathologist's report on histological type and grade 1, 2
• Determine estrogen receptor (ER), progesterone receptor (PgR), and HER2 status by IHC or FISH/CISH 1, 2
• Assess Ki67 proliferation index 2
• If axillary involvement is suspected clinically or on ultrasound, perform needle cytology of axillary nodes 1

Clinical TNM Staging

• Assign clinical TNM stage based on physical examination and imaging findings 1

Risk-Stratified Distant Metastasis Workup

Early Stage Disease (Stage I, Stage II with ≤3 positive nodes, clinically node-negative)

Do NOT perform routine distant staging investigations in asymptomatic patients with early stage breast cancer, as they do not benefit from comprehensive radiological staging 1, 2

Indications for Distant Staging Investigations

Perform chest X-ray (or CT), abdominal ultrasound or CT scan, and bone scintigraphy in the following scenarios:

• Neoadjuvant systemic therapy is planned 1, 2
• Clinically positive axillary nodes 1, 2
• Large tumors (≥5 cm) 1, 2
• Clinical signs, symptoms, or laboratory values indicating metastases 1, 2
• Locally advanced disease (Stage III) 1

Role of PET-CT

• Not recommended for routine staging of early breast cancer due to high false-negative rates for small lesions and poor sensitivity for axillary nodes 2
• May be useful when conventional imaging is inconclusive or for locally advanced/inflammatory disease candidates for neoadjuvant chemotherapy 2

Surgical Staging of Axilla

• Sentinel lymph node biopsy is the recommended procedure for clinically node-negative (cN0) breast cancer 1
• Provides pathological assessment of nodal status including isolated tumor cells, micrometastases (0.2-2 mm), and macrometastases 1

Postoperative Pathological Staging

The surgical specimen must include:

• Pathological TNM (pTNM) classification 2
• Histological type and grade using standardized grading system 1
• Evaluation of resection margins (location and minimum distance) 1
• Vascular and lymphovascular invasion 1
• Total number of lymph nodes removed and number positive 2
• Confirmation of ER, PgR, HER2 status and Ki67 on surgical specimen 1

Additional Considerations

Cardiac Assessment

• Mandatory cardiac ultrasound or MUGA scan before starting anthracyclines and/or trastuzumab 2

Genetic Testing

• Offer BRCA1/BRCA2 testing to patients with strong family history of breast/ovarian/pancreatic cancer, personal history of ovarian cancer, second breast cancer, or male sex 2

Critical Pitfalls to Avoid

• Do not over-stage early disease: Intensive surveillance imaging in asymptomatic Stage I patients provides no survival benefit 2
• Avoid routine PET-CT in early-stage disease: Low sensitivity and high false-positive rates make it inappropriate for routine use 2
• Early stage patients (N0) do not profit from comprehensive radiological staging and should not undergo routine bone scans, liver imaging, or chest X-rays 1