Pre-operative MRI in patients with ductal carcinoma in situ: Is MRI useful for identifying additional disease?

To determine if pre-operative MRI is useful for identifying additional disease that would impact surgical management in women with ductal carcinoma in situ (DCIS).

We conducted a retrospective review of consecutive women with calcifications at mammography yielding DCIS at core biopsy from 2007 to 2016 who subsequently underwent MRI examinations. Patient characteristics, imaging findings, and pathology outcomes were collected from the medical records. Standard statistical tests were used to compare the patients who underwent MRI examinations (MRI group) and those who did not (no MRI group).

963 women (age 58 years, range 28-89 years) presented with calcifications that yielded DCIS at biopsy, of whom 236 (24.5 %) underwent MRI examinations. The MRI group was younger, less likely to have a prior breast cancer, and more likely to have dense breasts than the no MRI group (all p < 0.001). 66 women (28.0 %) had 80 MRI findings that were recommended for work-up and/or biopsy. 21 patients had 23 MRI findings that were not pursued pre-operatively, and 45 patients with 57 MRI findings underwent biopsy. The positive predictive value of biopsies performed (PPV3) was 45.6 % (26/57). 26 cancers were detected in 24 women; thus, MRI detected additional sites of cancer in 11.2 % (24/215) of patients. Of the 26 cancers, 13 (50.0 %) were DCIS and 13 (50.0 %) were invasive.

MRI in selected women with DCIS identified additional sites of disease in 11.2 % and thus could be considered in the pre-operative evaluation of this specific patient cohort.