Melissa Yip MD, Presenter: Nothing to Disclose

Roberta A Jong MD, Abstract Co-Author: Nothing to Disclose

Petrina Ann Causer MD, Abstract Co-Author: Nothing to Disclose

To review the MRI appearance of breast cancers detected in our multimodality screening trial of high-risk patients. To hypothesize on the origins of false-negative screening examinations.

The study population consists of patients diagnosed with breast cancer in the 6 years of our multimodality breast cancer screening trial. Retrospective review was performed by 2 independant radiologists, with extensive background in breast imaging and in particular breast MRI, of the patients' screening MRIs in light of their pathological results. One of the radiologists also reviewed the patients' mammograms. Pertinent findings were described according to the BIRADS MRI lexicon. Note was made of technical pitfalls and background parenchymal enhancement.Data collected included pathological results, patient age and risk factors, breast density and results of ultrasound and physical examination.

36 cancers (2 bilateral) in 34 patients were diagnosed from November 97- November 03, in 1 to 5 rounds of screening. The average age of patients was 46 (34-64). 27 of patients were proven mutation carriers and pedigree was the risk factor in 5. 12 patients had a previous history of breast cancer. Tumour type: 8 pure DCIS, 2 DCIS with microinvasion, 2 invasive lobular, 24 invasive ductal. In the case of invasive tumours, the average diameter at pathology was 10 mm (2-20).MRI had retrospectively demonstrated 34 of the 36 cancers (sensitivity 94%). 18 patients had previous MRIs. In 8/18 (44%), both readers agreed that previous MRIs showed findings suspicious for cancer (birads 4 or 5). In another 5/18 (28%), one of the readers considered findings on previous MRIs to be suspicious for malignancy.

As we have learned in mammography, we believe that careful review of "missed" cancers on breast MRI will help to improve sensitivity. In a high-risk population, cancers may present with subtle or atypical findings.

Yip, M, Jong, R, Causer, P, High-Risk Screening with Contrast-enhanced Dynamic Breast MRI: Analysis of False Negative Results after 6-years' Experience.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4408576.html