Study: Breast MRI screening results in higher biopsy rates
According to a study published in JAMA Internal Medicine, women with and without a personal history of breast cancer (PHBC) who undergo breast screening with magnetic resonance imaging (MRI) are more likely to have biopsies and less likely to subsequently be diagnosed with cancer than women who undergo mammography alone.
The findings are based on analysis of data from 6 community-based Breast Cancer Surveillance Consortium (BCSC) registries from 2003 to 2013. Included in the study were 812,164 women with at least 1 screening digital mammogram or screening breast MRI who had a total of 2,048,994 screens. The median number of screens was 2 for mammography and 1 for MRI. Demographic and breast cancer risk factor data were collected through a self-reported questionnaire completed at each screening examination. All biopsies were linked with an individual screening episode and the biopsy result was based on the most invasive finding (invasive > ductal carcinoma in situ [DCIS] > high-risk benign > benign).
More than 100,000 mammograms from more than 36,000 women with PHBC and more than 1.9 million episodes in nearly 800,000 women without PHBC were reflected in the study. There were 3763 MRI scans in 2323 women with a PHBC and 4673 in 3149 women without PHBC. Biopsy rates were higher following MRI than following mammography (6.3% [n=236] versus 2.2% [n=2231]) in women with PHBC and 10.5% (n=489) versus 1.6% (n=30,757) in women without a PHBC.
The researchers found that, compared with MRI, mammography with core and surgical biopsies was more likely to yield DCIS and invasive breast cancer and less likely to result in a benign biopsy regardless of whether a woman had PHBC. In women with PHBC, 531 (34.7%) core biopsies that followed mammograms were diagnosed as DCIS or invasive cancer compared with 32 (19.5%) core biopsies that followed MRIs. MRIs were also more likely than mammograms to be performed on women with a first-degree family history of breast cancer.
The researchers found that regardless of PHBC status, rates of diagnosis of DCIS and invasive cancer were higher following mammography than following MRI, but the rates were significantly higher following mammography in women with a PHBC. However, higher rates of high-risk benign lesions were detected following MRI compared with mammography regardless of PHBC.
The study had a few strengths and limitations. One strength was inclusion of biopsy and intensity from 2,040,558 mammograms and 8436 MRI scans from 136 BCSC community and academic radiology facilities that were linked to pathology databases. The authors also felt that the study included a geographically and racially representative US population sample. Some of the limitations included misattribution of the most significant pathological finding and inability on the part of the researchers to evaluate biopsy guidance. Ultimately, the authors noted that more research is needed to identify women who would benefit most from MRI screening in order to balance the benefit-to-harm ratio.