Screening for breast cancer at early stages is vital for improving treatment outcomes. Kuhl and colleagues found that MRI screening for breast cancer can help detect cancer at earlier stages than traditional mammograms.
Breast cancer is the second most frequent type of cancer among women. Diagnosing breast cancer at early stages can reduce mortality significantly, so doctors typically recommend women start screening for breast cancer at about 40 years of age. However, mammograms are not very sensitive or accurate, and about one-third to one-half of all breast cancer becomes visible in between mammograms. An alternative to mammograms is MRI, which has been used for women at high risk of breast cancer. However, the effectiveness of MRI at detecting cancer in low-risk groups is unknown.
A new study published in Radiology by Kuhl and colleagues aims to assess the usefulness of MRI as a screening tool in women at low risk of breast cancer. They performed a prospective study, following 2120 between the ages of 40 and 70 over a period of at least two years for a total of 7007 women-years. The women had no breast cancer diagnosis and no family history of breast cancer at the start of the study. The women received both standard mammograms and MRI screenings, eight days apart on average, over the course of the study.
The researchers identified 61 cases of breast cancer over the study period. Of these, 60 were only detected using MRI and not traditional mammograms and only one, a highly invasive cancer, was detected using both MRI and a traditional mammogram. The differences between MRI and traditional mammogram detection rates were significant. None of the participants were diagnosed with cancer between screenings or at the two-year follow-up after the last screening in the study.
Kuhl and colleagues conclude that MRI is a useful additional screening tool that performs better than other methods for screening for breast cancer. It performs as well in the low-risk group as in the high-risk groups for which it has been used in the past, and can help identify cancers at early stages before they become more advanced. Further, the use of MRIs rather than standard mammograms could increase the interval between breast cancer screenings. Although MRI is expensive, it could potentially lead to reduced costs overall, as it would require fewer follow-ups to confirm the presence of breast cancer than traditional mammograms.
Written by C. I. Villamil
Reference: Kuhl et al. 2017. Supplemental Breast MR Imaging Screening of Women with Average Risk of Breast Cancer. Radiology 283(2).