Sandra Brennan MBBCh, MSc, Presenter: Nothing to Disclose

Laura Liberman MD, Abstract Co-Author: Nothing to Disclose

D. David Dershaw MD, Abstract Co-Author: Nothing to Disclose

Elizabeth A. Morris MD, Abstract Co-Author: Nothing to Disclose

To determine the cancer detection and benign biopsy rate in women who have breast MRI screening due to prior breast cancer, and to determine the size and stage of breast cancers found.

IRB-approved retrospective review of 1699 breast MRIs from 1999-2001 yielded 144 women with prior breast cancer who commenced breast MRI screening during that time and had >1 year MRI follow-up. Prior breast cancer histology in 144 was invasive in 126 (95 ductal [IFDC], 26 lobular [ILC], 4 mixed lobular and ductal, and 1 unknown) and ductal carcinoma in situ (DCIS) in 18 (12%). Biopsy rate and results were reviewed. Minimal breast cancer was defined as DCIS or node-negative invasive breast cancer <1 cm. Findings on mammography (M), ultrasound (US) and physical examination (PX) after MRI and screening year at time of cancer detection were noted. Median MRI follow-up was 4 (range, 1-9) years.

 Among 144, biopsies were prompted by MRI in 44 (31%) yielding malignancies in 17 (12%) of 144  (including seven who also had benign biopsies) and benign findings only in 27 (19%). Of 17 with MRI-detected malignancies, 1  had 2 metachronous cancers, hence 18 malignancies were found: 17 cancers and 1 myxoid liposarcoma. Of 17 cancers, 12 (71%) were invasive (ductal in 11 and lobular in 1) and 5 (29%) were DCIS; 10 (59%) were minimal breast cancers. Median histologic size of invasive cancer was 0.8 (range, 0.2-4.3) cm. Three (18%) of 17 cancers, representing 3 of 12 (25%) invasive cancers, had axillary metastases. Prior breast cancer histology had no significant impact on cancer detection rate. Of 17 cancers, 10 were nonpalpable, detected by MRI only; 7 had correlates on post-MRI M (n=2), US (n=2), or US, M, and PX (n=3). The 10 “MRI only” cancers, vs. 7 cancers later found by other means, were more likely DCIS (4/10=40% vs. 1/7=14%, p=0.3) or minimal breast cancers (7/10=70% vs. 3/7=43%, p=0.3). Six (35%) of 17 cancers were detected in screening year 1, six (35%) in year 2, two (12%) in year 4, and one in each of years 5, 6, and 9.

Among women with prior breast cancer, malignancies were found in 12% who had screening MRI and in 39% who had biopsies prompted by MRI. 70% of the breast cancers were found during the first two screening years and more than half were minimal breast cancers.

In patients with a personal history of breast cancer annual screening with breast MRI may be beneficial.

Brennan, S, Liberman, L, Dershaw, D, Morris, E, Breast MRI Screening of Women with Prior Breast Cancer: Preliminary Results.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6018867.html