What are the recommended screening options for a patient with heterogenous dense breast tissue and a negative mammogram (mammography)?

Screening Options for Heterogeneous Dense Breast Tissue with Negative Mammogram

For women with heterogeneously dense breasts and a negative mammogram, standard mammography screening alone remains the recommended approach, as supplemental screening with ultrasound, MRI, or automated breast ultrasonography has not demonstrated sufficient mortality benefit to justify routine implementation. 1

Understanding Dense Breast Tissue

Dense breast tissue is common, affecting approximately 43% of women aged 40-74 years who are classified as having heterogeneously or extremely dense breasts 1. This condition:

• Is most prevalent in women aged 40-49 years and decreases with age
• Represents an independent risk factor for developing breast cancer (relative risk of 1.23-1.30 depending on age group)
• Reduces mammography's sensitivity in detecting cancer
• Does not increase risk of dying from breast cancer after adjusting for stage, treatment, and other factors 1

Evidence on Supplemental Screening Options

Hand-Held Ultrasound (HHUS)

• Increases cancer detection compared to mammography alone 1
• Lacks evidence for mortality benefit
• Increases false positives and recall rates
• Has high incremental costs ($560 per woman aged 50-74 years) with questionable cost-effectiveness ($238,550 per quality-adjusted life-year) 1

Automated Breast Ultrasonography (ABUS)

• Increases cancer detection but with uncertain clinical significance
• Increases recall rates
• Has insufficient evidence linking detection to mortality outcomes
• Not recommended by the European Commission Initiative on Breast Cancer (ECIBC) 1

MRI

• Markedly increases breast cancer detection rates
• Raises concerns about overdiagnosis
• Has no evidence for mortality benefit
• Has potential side effects from contrast medium
• Significantly higher costs than mammography
• May result in net harm according to the ECIBC 1

Special Considerations

Extremely Dense vs. Heterogeneously Dense Breasts

• Extremely dense breasts carry a higher relative risk (2.1) compared to heterogeneously dense breasts (1.2) 1
• Some providers may consider women with extremely dense breasts to no longer be at average risk 1

False Positive Risk

• Women with dense breasts have increased risk of false-positive results and unnecessary biopsies
• Annual screening (vs. biennial) further increases this risk:
  • 69% cumulative probability of false-positive over 10 years with annual screening vs. 21% with biennial screening
  • 12% unnecessary biopsy rate with annual screening vs. 3% with biennial screening 1

Current Practice and Legislation

• 24 states require patient notification of breast density status 1
• Some states require informing women to consider supplemental screening
• No clinical practice guidelines explicitly recommend routine supplemental screening for women with dense breasts and negative mammograms 1

Algorithm for Approaching Dense Breast Tissue

1. Confirm breast density category (heterogeneously dense = BI-RADS category C)
2. Assess other risk factors beyond breast density
3. For average-risk women with heterogeneously dense breasts:
   • Continue routine mammography screening
   • Do not routinely implement supplemental screening 1
4. For women with additional risk factors or extremely dense breasts:
   • Consider comprehensive risk assessment
   • Consider supplemental screening options based on individual risk profile

Pitfalls to Avoid

• Don't automatically recommend supplemental screening based solely on breast density
• Don't assume that increased cancer detection with supplemental screening translates to mortality benefit
• Be aware that breast density classification may change between screenings
• Consider the high false-positive rates and unnecessary biopsies associated with supplemental screening
• Recognize the substantial resource implications and cost-effectiveness concerns of supplemental screening

While supplemental screening methods can detect additional cancers in women with dense breasts, current evidence does not support their routine use in women with heterogeneously dense breasts and negative mammograms due to lack of demonstrated mortality benefit, increased false positives, and resource considerations.