Study: Yearly breast MRI screening improves outcomes for women with inherited BRCA mutations

Relevance: Medium-High

Strength of Science: Medium-High

Research Timeline: Human Research

Relevance Rating Details

What is this study about?

This international study looked at whether yearly breast MRI screening reduces the risk of death from breast cancer among women with a BRCA1 or BRCA2 mutation. Researchers compared the number of deaths due to breast cancer among mutation carriers who had regular breast MRI screenings to those who did not.  

Why is this study important?

Women with a BRCA1 or BRCA2 mutation have a very high risk for breast cancer. Expert guidelines outline three main options for managing this risk:

• risk-reducing mastectomy
• medication to lower risk (e.g., tamoxifen)
• increased surveillance using a combination of mammograms and MRIs

These guidelines vary by country. In the United States, the National Comprehensive Cancer Network (NCCN) creates guidelines for cancer screening, prevention and treatment. The NCCN recommends yearly breast MRI screening beginning at age 25 for people with a BRCA1 or BRCA2 mutation. Therefore, it is important to know if breast MRIs reduce the risk of death from breast cancer among mutation carriers.

Most study participants received increased screening by adding a yearly breast MRI to their other screenings to detect cancer early.

Study findings

The study involved 2,488 women (people assigned female at birth) from 59 centers in 11 countries. Among these women, 2,004 had a BRCA1 mutation, while 484 had a BRCA2 mutation. Most participants (1,756: 1,442 BRCA1 and 314 BRCA2 mutation carriers) had at least one screening MRI. The remaining 732 women (562 BRCA1 and 170 BRCA2 mutation carriers) did not have breast MRIs.

Follow-up began when participants entered the study (at age 30 or older). The average follow-up time was just over nine years.

Throughout the study:

• 344 women developed breast cancer. Of these:
  • 241 had breast MRIs.
  • 103 did not have breast MRIs.
  • 35 died from their disease.

Among the women who died of breast cancer:

• 21 did not have breast MRIs.
  • 18 had a BRCA1 mutation.
  • 3 had a BRCA2 mutation.
• 14 had breast MRIs.
  • 12 had a BRCA1 mutation.
  • 2 had a BRCA2 mutation.

Breast MRI significantly reduced deaths from breast cancer in BRCA1 mutation carriers. Unfortunately, due to study limitations, including a small sample size, more research of women with BRCA2 mutations is needed to better understand how breast MRI screening impacts death from breast cancer.

Overall, this study showed that the risk of death by age 75 due to breast cancer was 20.5 percent for those who did not undergo MRI surveillance, compared to 5.5 percent for those who did.