MRI in the Early Detection of Breast Cancer in Women with High Genetic Risk

Abstract

Aims and background Women with BRCA1 or BRCA2 germline mutations have an elevated risk of developing breast and/or ovarian cancer. Because of the early onset of the disease, screening of this group of women should start at an earlier age than in the general population. The association of breast magnetic resonance imaging (BMRI) and ultrasonography (US) with mammography (MX) and clinical breast examination (CBE) in the regular surveillance of these individuals has been proposed and seems to improve the early detection of breast cancer. Methods Within a multicenter study started by the Istituto Superiore di Sanita (Rome), at the Istituto Nazionale Tumori of Milan (INT) we enrolled 116 women at high genetic risk for breast cancer; they were either BRCA1 or BRCA2 mutation carriers or had a strong family history of breast cancer. They underwent CBE, MX, US and BMRI once a year. Results Between June 2000 and April 2005, at INT 12 cancers were detected among the 116 screened individuals (10%). In this subgroup, 1 patient refused BMRI and in 2 cases US was not performed. With BMRI we found 11 cancers and 6 of them were detectable only by this technique. In these 6 cases, the size of the disease was less than 1 cm and MX was false negative due to irregularly nodular parenchyma in 4 cases and scar tissue or prosthesis in the other 2. US was not performed in 2 cases and was false negative in 4 cases. Three false positive results were found with BMRI: 1 case was considered suspect but related to hormonal influences; 1 case with the same pattern was sent for second-look US, which gave a negative result and BMRI review after 6 months showed normalization of the parenchyma; in the third case histology revealed the presence of adenosis. No false positive results were registered for MX. Conclusions The aim of secondary prevention is the detection of cancer at its earliest stage. BMRI screening in women with BRCA1 or BRCA2 mutations or at high familiar risk appears to be highly sensitive and may detect mammographically occult disease. The accuracy of MR imaging is higher than that of conventional imaging but the technique is flawed by a lower specificity. In order to avoid unnecessary biopsies we believe that the combination of BMRI and conventional imaging can be very useful in screening women with a high genetic risk of breast cancer, especially with second-look evaluation by means of US when BMRI yields the only positive diagnostic result. Second-look US has been demonstrated to be of critical importance both in recognizing false positive BMRI results and in guiding biopsies, when necessary.

Clinical Considerations ofBRCA1- andBRCA2-Mutation Carriers: A Review

“…Rijnsburger et al [60] found that 45.8% of breast cancers in BRCA- mutation carriers and 30.8% of breast cancers in BRCA2- mutation carriers were detected only by MRI. However, MRI specificity for cancer detection is lower than that of conventional screening, thereby resulting in more unnecessary biopsies [61]. Thus, it may be prudent to use MRI in conjunction with conventional imaging in screening women with a high genetic risk of breast cancer.…”

“…Thus, it may be prudent to use MRI in conjunction with conventional imaging in screening women with a high genetic risk of breast cancer. In the study by Trecate et al [61], it was advised to consider ultrasound evaluation when MRI yielded the only positive diagnostic result. …”

Patterns of Nonmasslike Enhancement at Screening Breast MR Imaging of High-Risk Premenopausal Women

“…Breast magnetic resonance (MR) imaging has been shown to have high sensitivity for the detection of breast cancer in high-risk women. Investigators have demonstrated that the cancer detection rate of screening breast MR imaging in women considered to have a high lifetime risk of developing breast cancer is on the order of 10 times that of screening mammography in the normal-risk population and ranges from 3.5% to 9% (1)(2)(3)(4)(5)(6). Many of the breast cancers in these series were otherwise undetected with clinical examination, mammography, or ultrasonography (US).…”

Basal Phenotype in Breast Carcinoma Occurring in Women Aged 35 or Younger

“…As BRCA1 mutation carriers may develop breast cancer earlier than those who do not have such a genetic predisposition [3,6], young women diagnosed with breast cancer may also have an elevated probability to carry a BRCA1 mutation [7][8][9]. Recent studies on breast cancer indicate that BRCA1-related carcinomas are more likely to express a basal epithelial phenotype [10][11][12][13][14].…”