What is the recommended follow-up for a patient with heterogeneously dense breasts on a mammogram?

Follow-Up Recommendations for Heterogeneously Dense Breasts on Mammogram

For patients with heterogeneously dense breasts on mammogram, supplemental screening with breast MRI or abbreviated breast MRI (AB-MRI) is recommended to improve cancer detection rates and reduce interval cancers. 1

Understanding Breast Density and Its Implications

• Heterogeneously dense breast tissue is common, affecting approximately half of women undergoing screening mammography 1
• Dense breast tissue presents two significant challenges:
  • Reduced mammographic sensitivity (30-48% decrease in extremely dense breasts) 1
  • Independent risk factor for breast cancer development 1
• Women with heterogeneously dense breasts experience both higher risk of developing breast cancer and greater risk of cancer not being detected on standard mammography 1

Recommended Follow-Up Approach

Primary Recommendation: Supplemental MRI Screening

• Abbreviated breast MRI (AB-MRI) or full protocol breast MRI shows the highest cancer detection rates for women with heterogeneously dense breasts 1
• AB-MRI demonstrated a cancer detection rate of 15.2 per 1,000 examinations compared to 6.2 per 1,000 with digital breast tomosynthesis (DBT) in women with dense breasts 1
• The EA1141 trial showed AB-MRI had significantly higher sensitivity (95.7%) compared to DBT (39.1%) for detecting invasive cancer and DCIS in women with dense breasts 2
• Cancers detected by MRI tend to be smaller, lymph node negative, and less biologically aggressive 1

Alternative Supplemental Screening Options

• Digital Breast Tomosynthesis (DBT):

  • Improves lesion characterization in non-calcified lesions compared to conventional mammography 1
  • Shows increased cancer detection rates in both dense and non-dense breast tissue 1
  • Should be considered when MRI is contraindicated or unavailable 1

• Whole Breast Ultrasound:

  • May be considered as a supplemental screening option for women with dense breasts 1
  • Increases cancer detection but comes with higher false-positive rates and lower positive predictive values for biopsies 1
  • No added benefit when used in conjunction with MRI screening 1

Important Considerations and Caveats

• Baseline supplemental imaging may result in benign biopsies or short-term interval follow-up recommendations 1
• The DENSE trial showed supplemental MRI screening in women with extremely dense breasts reduced interval cancer rates from 5.0 to 2.5 per 1,000 screenings 3
• The American College of Radiology now recommends that patients be notified of their breast density and informed that supplemental imaging may be beneficial 1
• Risk assessment should be performed for all women by age 25 to better stratify screening recommendations 1

Algorithm for Follow-Up Decision Making

1. Confirm heterogeneously dense breast tissue on mammogram
2. Assess additional risk factors (family history, prior breast biopsies, etc.)
3. For average-risk women with heterogeneously dense breasts:
   • First choice: AB-MRI or full protocol breast MRI 1
   • Second choice: Whole breast ultrasound if MRI is contraindicated 1
   • Consider DBT if other supplemental screening is unavailable 1
4. For intermediate or high-risk women with heterogeneously dense breasts:
   • Breast MRI or AB-MRI is strongly recommended regardless of breast density 1

By following these evidence-based recommendations, clinicians can help improve early detection of breast cancer in women with heterogeneously dense breasts, potentially reducing breast cancer mortality and morbidity.