New American Cancer Society Recommendations
For Breast Screening with MRI
Breast MRI is quickly becoming a standard technique used in the evaluation and detection of breast cancer. With advanced MRI techniques, the sensitivity is now approximately 100% for detecting breast cancers as small as 3mm and finds 2-8% more cancers in high risk patients than physical examination and mammography alone. Although mammography and physical exam may be limited due to breast anatomy, Breast MRI sensitivity is independent of breast size, density, patient age, presence of implants, or prior surgery. Overall, utilizing Breast MRI leads to the detection of more cancers earlier with a more favorable tumor stage.
Breast MRI is however costly and few centers perform the test. Many patients become anxious in an MRI scanner and need sedation. More importantly, many benign lesions appear indeterminate or frankly malignant on an MRI leading to a higher call back rate or biopsy rate than mammography. It is for this last reason that the recent 2007 American Cancer Societies (ACS) guidelines concerning breast screening with MRI and mammography was very specific about which patients should have an MRI.
In general, ACS recommended Screening Breast MRI in patients with at least a 20-25% lifetime risk of developing breast cancer. This group predominantly includes those women who carry a genetic mutation called the BRCA1 or BRCA2 gene, which imparts a 45-65% risk of developing breast cancer by age 70 and also a higher risk of ovarian cancer. These genetic mutations are not rare, with its prevalence in society being 1/500 to 1/1000, and 1/50 in Ashkenazi Jews. Since this is a hereditary condition, the sister, mother, or daughter of a woman carrying a BRCA mutation has a 50% chance of having the same mutation. Other hereditary syndromes, which the ACS recommended Screening Breast MRI, include Li-Fraumeni, Cowden, and Bannavan-Ruvalcata syndromes however these are extremely rare syndromes.
It is also recommended that women who have had chest radiation between ages 10 and 30 obtain annual screening with Breast MRI. These women who may have had mantle field radiation for lymphoma have had their breast tissue exposed to high dose radiation at an early age increasing their later risk of developing breast cancer.
A woman may have a risk >20-25% based on other factors for which a risk assessment tool can be used to determine lifetime risk. Risk assessment can be performed by your physician or using an online tool, such as that available through the National Cancer Institute located at www.cancer.gov/bcrisktool.
Studies so far do not support the use of Screening Breast MRI in women who have a higher risk of breast cancer than most but still less than 20%. This includes women with dense breast tissue on mammography or a prior history of breast cancer, noninvasive breast cancer, or premalignant condition such as ductal carcinoma in-situ, lobular carcinoma in-situ, or atypical ductal hyperplasia.
Part of performing Breast MRI and detecting a lesion is being able to biopsy the lesion. It is expected that the American College of Radiology will soon require centers that do Breast MRI to also perform Breast MRI Biopsies, which is now only rarely done in the community. The North Broward Hospital District is however proud to that both Coral Springs Medical Center and Broward General Medical Center offer Breast MRI and Breast MRI biopsy.
In conclusion the American Cancer Society has just recommended Screening Breast MRI for many women in our community. Women can obtain genetic testing from their doctor or review risk modules to determine their exact risk. If genetically predisposed or if risk is greater than 20-25%, annual screening MRI as early as 25 years of age should begin. Please note that Breast MRI is not a replacement for mammography or physical examination as some conditions such as ductal carcinoma in-situ, a noninvasive breast cancer, are difficult to see on MRI. These ACS recommendations were just released in March 2007 and your doctor may not be aware of these recommendations.