Emerging research suggests that magnetic resonance imaging (MRI) surveillance significantly reduces long-term breast cancer mortality risk for women with the BRCA1 gene.
For the multinational study, recently published in JAMA Oncology, researchers reviewed questionnaire data from 2,004 women with BRCA1 sequence variations and 484 women with BRCA2 sequence variations. According to the study, 1,756 women had at least one MRI screening exam (mean of 4.7 exams) and 732 study participants had no MRI exam. In addition to a baseline questionnaire, the researchers said study participants completed follow-up questionnaires every two years up until breast cancer diagnosis, bilateral mastectomy, death, or the last completed follow-up questionnaire. The mean age of participants entering the study was 41.2 and the mean follow-up period was 9.2 years.
The study authors found that that 20-year cumulative risk for breast cancer mortality was 3.2 percent for those who had MRI surveillance in comparison to 14.9 percent for women with no MRI surveillance.
In the MRI surveillance cohort, researchers noted an 0.87 hazard ratio (HR) for women with BRCA2 sequence variation and an 0.20 HR for those with a BRCA1 sequence variation.
“This cohort study supports the recommendation that women with BRCA1 sequence variations aged 30 years or older should be offered MRI surveillance. We observed an 80% reduction in breast cancer mortality for women with BRCA1 sequence variations after they entered an MRI surveillance program,” wrote study co-author Steven A. Narod, M.D., FRCPC, FRSC, a senior scientist and director of the Familial Breast Cancer Research Unit at the Women’s College Research Institute at the University of Toronto, and colleagues.
Three Key Takeaways
- MRI surveillance significantly reduces breast cancer mortality risk. The 20-year cumulative risk for breast cancer mortality was found to be 3.2% for women with MRI surveillance in contrast to 14.9% for women without MRI surveillance.
- Substantial reduction in mortality with MRI surveillance for women with BRCA1 sequence variations. The study revealed an 80 percent reduction in breast cancer mortality for women with BRCA1 sequence variations who enter an MRI surveillance program. The hazard ratio (HR) for women with with BRCA1 sequence variations was 0.20. This finding supports the recommendation that women with BRCA1 sequence variations aged 30 years or older should be offered MRI surveillance.
- Importance of early and regular MRI screening. The data underscore the importance of initiating screening MRI examinations before age 35 and adhering to an annual screening schedule. The study emphasizes that early and regular MRI screening can contribute to a higher 10-year survival rate for women diagnosed with invasive breast cancer. The 10-year survival rate was 93.8% for those with MRI surveillance compared to 86.7% for those without MRI surveillance.
The researchers noted 21 breast cancer deaths in the no MRI cohort of 732 women in comparison to 14 deaths in the MRI surveillance cohort of 1,756 women. Of the 14 deaths in the MRI surveillance group, the researchers found that for six women, more than one year had passed since their last MRI exam and five women had their initial diagnosis with their first MRI screening.
“These data emphasize the importance of starting screening MRI examinations before age 35 years and adhering to an annual screening schedule,” noted Narod and colleagues.
For women diagnosed with invasive breast cancer, the 10-year survival rate for those with MRI surveillance was 93.8 percent in comparison to 86.7 percent in the group with no MRI surveillance, according to the study authors.
(Editor’s note: For related content, see “Study Shows BPE Quantification on MRI Helps Predict Risk of Breast Cancer Recurrence,” “Study: Abbreviated MRI and DBT Offer Comparable Breast Cancer Detection in Dense Breasts” and “Can DWI MRI Offer a Viable Non-Contrast Alternative for Breast Cancer Assessment?”)
In regard to study limitations, the researchers noted a lack of standard protocols for MRI acquisition as the MRI screening exams were performed in 11 countries. The study authors acknowledged a significant lack of diversity in the cohort with White women comprising over 97 percent of the study participants.
