# RECOMMENDATIONS (The recommendations were slightly modified with respect to risk category 5 during the 2017 ENDORSEMENT)
MRI in addition to mammography is recommended for women in target population risk categories 1, 2, 3, and 5 above. The evidence is insufficient to recommend MRI screening for patients in risk category 4.
- Multiple studies, four in abstract form, were identified that evaluated MRI in comparison to mammography in women at high risk for breast cancer. These studies all found superior sensitivity for the detection of breast cancer with MRI compared to mammography. MRI was also found by most studies to have inferior specificity to mammography, with higher recall and biopsy rates associated with MRI.

# Expert Opinion and Qualifying Statements
 While there is insufficient evidence at this time to make a definitive recommendation regarding the appropriate screening frequency, it is the opinion of the Working Group that women should be screened annually, as this was the frequency typical of the identified studies on which the recommendation for screening is based.  While there is insufficient evidence at this time to make a definitive recommendation regarding the ages of patients who should be screened, it is the opinion of the Working Group that women should be screened annually from 30 to 69 years of age. Age 30 is an appropriate age to begin screening as women at that age with BRCA mutations are at much greater risk of breast cancer than women aged 50 and older in the general population. Age 69 is an appropriate age to end screening because: the relative risk of cancer decreases with age in the population at hereditary risk; mammographic sensitivity increases with age; very few subjects were included in the studies greater than age 69; and the evidence for mortality reduction from screening in the general population is lacking for women older than age 70.

# Expert opinion and qualifying statements modified in the 2017 Endorsement:
 It is the opinion of the Working Group that the benefits of MRI in terms of increased sensitivity outweigh the potential harms of higher recall rates and biopsy rates for all women in risk category 5 who received 20 Gy radiation before the age of 30.  1.2017] . Accessed 20 November 2017). This (Ontario) Working Group, however, did not find justification for screening from age 25 in this group (or any of the other high risk groups). In particular, a review of one prospective and 3 retrospective studies published since 2011 that looked at the results of adding MRI to mammography for screening risk category 5 found only 3 cases of breast cancer detected before age 30 out of a total of 51 cases and all 3 of these were detected by both MRI and mammography (See Section 4 for additional information).  With respect to risk category 4, there are preliminary data that a subgroup of patients in risk category 4 might benefit from the addition of MRI to mammography (e.g., women who in addition to a high risk benign biopsy or previous breast cancer, also have breast density 50% and a family history of breast cancer though insufficient to put them in category 3 Copyright This evidence-based series is copyrighted by Cancer Care Ontario; the series and the illustrations herein may not be reproduced without the express written permission of Cancer Care Ontario. Cancer Care Ontario reserves the right at any time, and at its sole discretion, to change or revoke this authorization.