Lauren C. Friedlander MD, Presenter: Nothing to Disclose

Sara C. Gavenonis MD, Abstract Co-Author: Research support, Hologic, Inc

Susan G. Roth MD, Abstract Co-Author: Nothing to Disclose

To retrospectively determine the outcomes of screening breast MRI examinations performed in patients with lobular carcinoma in situ (LCIS).

We retrospectively reviewed the results of breast MRI examinations performed at the Hospital of the University of Pennsylvania from 1996 through September 2009 in patients with prior biopsies demonstrating LCIS. Patients with a prior breast cancer diagnosis were excluded. ACR BI-RADS descriptors and recommendations were recorded for each report, and the pathology results from all consequent biopsies were obtained from the electronic medical record.

We identified 445 breast MRI examinations completed in 198 patients with a history of LCIS, including 308 studies performed in 134 patients purely for screening purposes. Of these 308 studies, 255 (82.8%) were read as having normal or benign findings (BIRADS 1 or 2); 27 (8.8%) were read as having probably benign findings requiring short term follow-up (BIRADS 3); and 27 (8.8%) were read as having suspicious findings requiring biopsy (BIRADS 4 or 5). Of the 27 biopsies recommended, 10 (37%) yielded benign pathology, 5 (18.5%) yielded malignant pathology, and 7 (25.9%) yielded high risk lesions on pathology. Biopsy was not performed in 4 cases (14.8%) in which the suspicious lesions could not be re-identified and in 1 case (3.7%) for reasons which were uncertain. Of the 27 studies for which short term follow-up was recommended, 2 (7.4%) ultimately went on to biopsy, both yielding benign pathology. Overall, malignancy was detected in 5/308 screening studies (1.6%) and in 5/134 screened patients (3.7%). The positive predictive value incorporating all studies for which biopsy was recommended (PPV1) is 18.5%. The positive predictive value incorporating only those studies for which biopsy was recommended and actually performed (PPV3) is 23.8%.

Screening breast MRI identified breast cancer in patients with LCIS at a rate similar to that shown in higher risk populations for whom screening breast MRI is currently recommended. Revision of the current guidelines to recommend breast MRI screening in patients with LCIS may be appropriate.

Patients at increased risk for developing breast cancer because of a history of lobular carcinoma in situ are likely appropriate candidates for screening breast MRI.

Friedlander, L, Gavenonis, S, Roth, S, Results of MRI Screening for Breast Cancer in High Risk Patients with Lobular Carcinoma in Situ.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9002444.html