BACKGROUND AND PURPOSE:

• Lack of consensus on breast MRI for routine surveillance in asymptomatic women with a personal history of breast cancer
• Wernli et al. (Radiology, 2019) compared the performance of breast MRI to mammography alone for women with a personal history of breast cancer

METHODS:

• Observational cohort study
  • Data derived from Breast Cancer Surveillance Consortium (BCSC)
• Participants in Consortium
  • ≥18 years of age or older (mean age, 60 years ± 13)
  • Stage 0 to III
  • Underwent mammographic and/or breast MRI exams
• Groups
  • Mammography alone
  • Breast MRI
• Primary outcome: Performance measures of the two imaging techniques
  • Calculated by using end-of-day assessment and occurrence of second breast cancer events within 1 year of imaging
• Data analysis
  • Logistic regression to compare performance for breast MRI versus mammography alone,
    • adjusting for demographics, examination, and primary breast cancer characteristics
  • Analysis was conducted on a per-examination basis

RESULTS:

• 13,266 women
  • Mammography group: 11,745 | Breast MRI group: 1,521
  • Total examinations: 33,938 mammography | 2506 breast MRI
• Breast MRI was associated with
  • Younger age at diagnosis
  • Chemotherapy
  • Higher education and income

Raw performance measures (without adjustments) for breast MRI vs mammography were

• Cancer detection rates (per 1,000 exams)
  • MRI: 10.8 (95% CI, 6.7-14.8)
  • Mammography: 8.2 (95% CI, 7.3-9.2)
• Sensitivity
  • MRI: 61.4% (27/44) (95% CI, 46.5%-76.2%)
  • Mammography: 70.3% (279/397) (95% CI, 65.8%-74.8%)
• Biopsy rate
  • Breast MRI: 10.1% (95% CI, 8.9%-11.3%)
  • Mammography: 4.0% (95% CI, 3.7%-4.2%)
• In multivariable models, breast MRI, compared to mammography alone, was associated with
  • Higher biopsy rate: Odds ratio (OR) of 2.2 (95% CI, 1.9-2.7; P < .001)
  • Higher cancer detection rate: OR of 1.7 (95% CI, 1.1-2.7; P = .03)
  • No difference in sensitivity: OR of 1.1 (95% CI, 0.4-2.9; P = .84)
  • No difference for interval cancer rate: OR of 1.1 (95% CI: 0.6-2.2; P = .70)

CONCLUSION:

• While surveillance breast MRI resulted in higher biopsy and cancer detection rates in women with a personal history of breast cancer, no differences seen in sensitivity or interval cancer rates
• The authors conclude

…mammography did not miss more cancers that would become clinically detectable during the 1-year screening interval.

Comparisons of new imaging strategies for surveillance of women with a personal history of breast cancer need to account for differences in women, incident tumor, and treatment characteristics.

Learn More – Primary Sources:

Surveillance Breast MRI and Mammography: Comparison in Women with a Personal History of Breast Cancer

Related ObG Topics:

Mammography Guidelines for Average-Risk Women

How Effective Is Mammography in Reducing the Number of Advanced Breast Cancer Diagnoses?

Has Breast Density Legislation Had Any Impact on Breast Cancer Diagnosis? 

Can Ultrasonography in Addition to Mammography Improve Breast Cancer Screening Effectiveness?