Ductal Carcinoma In Situ (DCIS) at Breast MRI: Predictors of Upgrade to Invasive Carcinoma

Abstract

To determine the upgrade rate of magnetic resonance imaging (MRI)-detected ductal carcinoma in situ (DCIS) and to identify patient, imaging, and pathologic features that may predict the risk of upgrade. Medical chart review from January 2007 to December 2016 identified 60 patients with 61 cases of MRI-detected DCIS and negative mammographic evaluations within 1 year prior to the MRI. Imaging and pathology reports were reviewed. Standard statistical tests, including Student's t-tests and chi-square tests, were used to compare patient, imaging, and pathologic features between the cases of DCIS that did and did not upgrade to invasive carcinoma at surgery. Over a 10-year period, 60 patients (mean age 52 years, range 30-76 years) were diagnosed with 61 cases of MRI-detected DCIS. Two-thirds of DCIS cases were detected on MRI examinations that were performed for purposes of high-risk screening (67.2%, 41/61). MRI features that led to the DCIS diagnosis were nonmass enhancement in 78.7% (48/61), enhancing mass in 16.4% (10/61), nonmass enhancement and enhancing mass in 3.3% (2/61), and enhancing focus in 1.6% (1/61). Thirteen cases (21.3%, 13/61) were upgraded to invasive ductal carcinoma at surgery. DCIS cases that upgraded were larger on MRI (40 mm vs 17 mm, p < 0.01) and more likely to be associated with comedonecrosis at biopsy (38.5% [5/13] vs 6.3% [3/48], p < 0.01). The upgrade rate of MRI-detected DCIS to invasive ductal carcinoma at surgery is 21.3%. Features that are associated with upgrade include large size on MRI and the presence of comedonecrosis at biopsy.