Greater background parenchymal enhancement increases breast cancer risk
Researchers from Duke University Medical Center have found that women with greater than minimal background parenchymal enhancement (BPE) at an index MRI face increased risk of developing breast cancer, according to a study published online March 27 in Academic Radiology.
The relationship between BPE on MRI and breast cancer risk is not entirely clear from past research, according to researchers led by Lars Grimm, MD, MHS, an assistant professor of radiology at Duke.
Grimm and his colleagues identified 1,039 breast MRIs of high-risk women (<20 percent lifetime risk of breast cancer according to American College of Radiology criteria) who went for screening at Duke from August 1, 2004 to July 30, 2013. Researchers identified 61 participants who developed breast cancer after the index MRI. These 61 participants were then matched 1:2 by age and high-risk indication with 122 patients who did not have breast cancer, according to study methods.
Additionally, five radiologists recorded BPE in all participants. The median reader BPE for each was then calculated and compared between the participants with and without cancer, according to the researchers.
"The time to cancer diagnosis was calculated from the date of the index MRI to the date of pathologic confirmation of malignancy," Grimm et al. wrote. "The control cohort follow-up duration was calculated as the time between the index MRI date and the last follow-up breast imaging study, with patients selected having at least two years of imaging follow-up; breast density was reported from the corresponding mammogram reports when available."
Study results showed that participants with breast cancer were at high-risk because of a history of radiation therapy (six of 61 individuals), high-risk lesion (11 of 61) or breast cancer (18 of 61), while BRCA gene mutation (11 of 61) or family history (15 of 61) were also contributing factors. Subsequent tumors in these participants included invasive ductal carcinoma (39 of 61), ductal carcinoma in situ (18 of 61) and invasive lobular carcinoma (4 of 61).
"BPE was significantly higher in the cancer cohort than in the control cohort," the researchers wrote. "Women with mild, moderate or marked BPE were 2.5 times more likely to develop breast cancer than women with minimal BPE."
In addition to their findings, the researchers noted that reader variability is an unavoidable limitation of all imaging biomarkers in clinical practice. Grimm et al. suggested future research regarding BPE as a successful predictor of future breast cancer risk, as well as advising more radiologists to be trained in producing more consistent interpretations, developing computer algorithms to better establish a clinical BPE threshold and revising mammographic information to increase self-correctness for radiologists.
A recent graduate from Dominican University (IL) with a bachelor’s in journalism, Melissa joined TriMed’s Chicago team in 2017 covering all aspects of health imaging. She’s a fan of singing and playing guitar, elephants, a good cup of tea, and her golden retriever Cooper.