What is the recommended staging imaging approach for invasive ductal carcinoma (IDC)?

Staging Imaging for Invasive Ductal Carcinoma

For invasive ductal carcinoma (IDC), do NOT perform routine staging imaging with CT chest, bone scans, or PET scans in early-stage disease (clinical stage I or II), as these tests provide no treatment benefit and cause unnecessary harm through radiation exposure, false positives, and overtreatment. 1

Primary Breast Imaging Requirements

Bilateral diagnostic mammography is mandatory to identify the extent of disease, assess for multifocality, and evaluate the contralateral breast. 2 This serves as the foundation for all subsequent treatment planning.

• Ultrasound of the breast should be performed as needed to further characterize findings detected on mammography and evaluate any palpable abnormalities. 2
• The combination of mammography and ultrasound increases sensitivity to 93.3% for detecting additional disease. 3

Role of Breast MRI

Breast MRI with IV contrast is NOT routinely recommended for all patients with IDC, despite its superior sensitivity, because long-term outcome data do not support routine use and it frequently overestimates disease extent by 1-3 cm in up to 65% of cases. 1, 3

When to Consider Breast MRI:

• High-risk patients (BRCA mutations, strong family history) where MRI sensitivity of 94.6% provides significant additional value 3
• Dense breast tissue where mammography sensitivity is significantly reduced 3
• Suspected multicentric disease where MRI demonstrates 90% accuracy in predicting multicentricity 1, 4
• Young patients where mammography is less sensitive 3

Critical Caveats About MRI:

• MRI shows larger tumor sizes than mammography (median difference ~7mm), but overestimates disease in 65.2% of DCIS cases by mean of 1.97 cm 1, 3
• MRI is superior for detecting high-grade disease (92% sensitivity vs 56% for mammography) but may miss calcified low-grade DCIS 1, 3
• Only 67-84% of DCIS-associated calcifications show enhancement on MRI, so mammography remains essential for detecting calcified disease 3

Systemic Staging Imaging: What NOT to Do

The American Society of Clinical Oncology (ASCO) Choosing Wisely guidelines explicitly advise AGAINST routine performance of the following in early-stage breast cancer:

• CT chest (with or without IV contrast) 1
• PET scans 1
• Bone scans 1

These imaging modalities are inappropriate for clinical stage I or II disease because they lead to harm through unnecessary radiation exposure, misdiagnosis, unnecessary invasive procedures, overtreatment, and treatment-related complications. 1

When Systemic Staging IS Appropriate:

Only perform CT chest, bone scan, or abdominal imaging if:

• Patient has symptoms suggesting metastatic disease 2
• Laboratory abnormalities suggest distant disease 2
• Clinical stage IIIB, IIIC, or inoperable IIIA disease 2
• Stage IV (metastatic) disease is suspected 2

Essential Non-Imaging Staging Components

Complete staging workup includes:

• History and physical examination focusing on symptoms of metastatic disease 2
• CBC with platelets 2
• Liver function tests 2
• Pathology review with mandatory ER/PR/HER2 determination 2
• Genetic counseling if high-risk features present 2

Common Pitfalls to Avoid

Do not order "routine staging scans" in early-stage IDC—this is explicitly discouraged by ASCO and provides no survival benefit while causing measurable harm. 1

Do not assume MRI is always more accurate than mammography—MRI overestimates disease extent in the majority of cases and should be interpreted in conjunction with mammographic findings, particularly when calcifications are present. 1, 3

Do not skip bilateral mammography even if MRI is performed—mammography remains superior for detecting microcalcifications associated with DCIS and early-stage disease. 3

Do not perform ultrasound-guided biopsy for microcalcifications—stereotactic biopsy is required as ultrasound cannot reliably visualize calcifications. 1