What is the recommended screening protocol for women at high risk of breast cancer, including the use of MRI (Magnetic Resonance Imaging)?

MRI Breast Screening for High-Risk Breast Cancer

Annual breast MRI screening should be performed in addition to mammography for women at high risk of breast cancer, including those with genetic mutations, a calculated lifetime risk of 20% or more, or a history of chest radiation therapy at a young age. 1, 2

Who Qualifies for Breast MRI Screening

MRI screening is recommended for the following high-risk groups:

1. Genetic predisposition:

   • BRCA1 or BRCA2 mutation carriers
   • Untested first-degree relatives of BRCA mutation carriers
   • Other high-risk genetic mutations (TP53, CHEK2, PTEN, CDH1, STK11, PALB2, ATM)

2. Calculated lifetime risk ≥20% based on risk assessment models

3. Radiation exposure history:

   • Women who received chest/mantle radiation therapy at a young age (≥10 Gy before age 30)

4. Personal history of breast cancer:

   • Women diagnosed before age 50
   • Women with personal history of breast cancer AND dense breast tissue

5. Other high-risk conditions:

   • Lobular carcinoma in situ (LCIS)
   • Atypical hyperplasia on prior biopsy (especially with other risk factors) 1, 2

Screening Protocol and Timing

• Genetic mutation carriers: Annual MRI beginning at age 25-30 1, 2
• Radiation therapy recipients: Annual MRI beginning 8 years after radiation therapy but not before age 25 1
• Calculated lifetime risk ≥20%: Annual MRI beginning at age 30 1
• Personal history of breast cancer: Annual MRI in addition to mammography 1

Effectiveness of MRI Screening

MRI significantly improves breast cancer detection in high-risk women:

• Combination of mammography and MRI yields 91-98% sensitivity 1
• MRI detects 8-29 additional cancers per 1,000 women screened 1
• Particularly high cancer detection rate (26 per 1,000) in BRCA mutation carriers 1
• MRI detects smaller, node-negative cancers at earlier stages 1
• Reduces interval cancers compared to mammography alone 1, 3

Limitations and Considerations

• Higher recall rates: MRI has a 15.1% recall rate versus 6.4% for mammography 1
• More biopsies: MRI leads to more image-guided biopsies (11.8% versus 2.4% for mammography) 1
• Resource intensive: Requires significant time, staff, and equipment resources 4
• Alternatives: For women who cannot undergo MRI, ultrasound should be considered as an alternative supplemental screening method 1, 2

Risk Assessment

• All women should be evaluated for breast cancer risk no later than age 30, especially Black women and those of Ashkenazi Jewish descent 1, 2
• Risk assessment should incorporate family history, genetic testing results, and other risk factors to determine appropriate screening protocols

Important Caveats

• MRI screening is not recommended for women at average risk of breast cancer 5
• Molecular breast imaging (MBI) is not recommended for screening in any high-risk population 1
• Despite higher false-positive rates with MRI, specificity improves with successive screening rounds 6
• While survival data are still pending, the earlier stage at diagnosis with MRI screening predicts a significant reduction in breast cancer mortality 6

The evidence clearly demonstrates that adding annual MRI to mammography significantly improves early detection of breast cancer in high-risk women, potentially reducing mortality through earlier diagnosis of more treatable disease.