#Grand Rounds

Breast Cancer Screening using MRI vs Mammography – How Do They Compare?

BACKGROUND AND PURPOSE:

Mammography is the only test with evidence demonstrating breast cancer mortality reduction
MRI is recommended for women at high risk for breast cancer (for example, those with BRCA mutations or others with >20% lifetime risk)
Current guidelines recommend annual mammography for women with treated breast cancer and restricts the use of MRI screening to those at high risk
Buist et al. (JAMA Internal Medicine 2018) measured the biopsy rates and yield in the 90 days following screening (mammography vs MRI) in women with a personal history of breast cancer and based on breast cancer risk in women without personal history

Observational cohort study
- Data from 6 Breast Cancer Surveillance Consortium (BCSC) registries
Participants
- Women with ≥ 1 screening digital mammogram or screening breast MRI from 2003 to 2013
Women received either
- Mammogram alone
- MRI with or without mammogram within 30 days
Primary outcomes (within 90 days of screening episodes)
- Biopsy intensity (most invasive procedure type)
- Biopsy yield (most invasive finding)
Outcomes were stratified by
- Personal history of breast cancer
- BCSC 5-year breast cancer risk among women without personal history of breast cancer

812,164 women undergoing screening were included with a total of 2,048,994 imaging episodes
- Women with personal history received 101,103 mammograms and 3,763 MRI screens
- Women without personal history received 1,939,455 mammograms and 4673 MRI screens
In women with personal history, age-adjusted core and surgical biopsy rates (per 1000 episodes) doubled in MRI group (57.1; 95% CI, 50.3-65.1) vs mammography (23.6; 95% CI, 22.4-24.8)
In women without personal history, age adjusted core and surgical biopsy rates (per 1000 episodes) were 5 times higher following MRI (84.7; 95% CI, 75.9-94.9) vs mammography (14.9; 95% CI, 14.7-15.0)
In women with personal history, ductal carcinoma in situ and invasive biopsy yield (per 1000 episodes) were higher following mammography (404.6; 95% CI, 381.2-428.8) compared with MRI (267.6; 95% CI, 208.0-337.8)
Women without a personal history showed a similar but nonsignificant trend
High-risk benign lesions were more commonly identified following MRI regardless of personal history
Higher biopsy rates and lower cancer yield following MRI were not explained by increasing age or higher 5-year breast cancer risk

Higher biopsy rates were expected with MRI because of its higher sensitivity and lower specificity compared with mammography
- Unlike positive mammography which is usually followed by further targeted mammography or ultrasound, positive screening MRI results are usually resolved with short-interval follow-up MRI or biopsy
Women with and without personal history had higher biopsy rates and lower cancer yield findings after undergoing a screening MRI experience
Authors point out that this is study looked at 90 day rates, while traditional screening performance takes in to account examination interpretation within 12 months follow-up for cancer outcomes
In addition, the authors state that “further work is needed to identify women who will benefit from screening MRI to ensure an acceptable benefit-to-harm ratio.”

< Previous

Next >