Multicenter comparative multimodality surveillance of women at genetic-familial high risk for breast cancer (HIBCRIT study): interim results

Breast tumor characteristics of BRCA1 and BRCA2 gene mutation carriers on MRI

The appearance of malignant lesions in BRCA1 and BRCA2 mutation carriers (BRCA-MCs) on mammography and magnetic resonance imaging (MRI) was evaluated. Thus, 29 BRCA-MCs with breast cancer were retrospectively evaluated and the results compared with an age, tumor size and tumor type matched control group of 29 sporadic breast cancer cases. Detection rates on both modalities were evaluated. Tumors were analyzed on morphology, density (mammography), enhancement pattern and kinetics (MRI). Overall detection was significantly better with MRI than with mammography (55/58 vs 44/57, P = 0.021). On mammography, lesions in the BRCA-MC group were significantly more described as rounded (12//19 vs 3/13, P = 0.036) and with sharp margins (9/19 vs 1/13, P = 0.024). On MRI lesions in the BRCA-MC group were significantly more described as rounded (16/27 vs 7/28, P = 0.010), with sharp margins (20/27 vs 7/28, P < 0.001) and with rim enhancement (7/27 vs 1/28, P = 0.025). No significant difference was found for enhancement kinetics (P = 0.667). Malignant lesions in BRCA-MC frequently have morphological characteristics commonly seen in benign lesions, like a rounded shape or sharp margins. This applies for both mammography and MRI. However the possibility of MRI to evaluate the enhancement pattern and kinetics enables the detection of characteristics suggestive for a malignancy.

Who Should Have Breast Magnetic Resonance Imaging Evaluation?

During the last two decades, tremendous advances have been made in the performance and interpretation of breast magnetic resonance imaging (MRI) examinations. Technical requirements for optimal breast imaging including the requirement for a breast MRI biopsy system are now being defined as part of a voluntary American College of Radiology (ACR) breast MRI accreditation program. The ACR BI-RADS (Breast Imaging Reporting and Data System) lexicon for breast MRI has brought uniformity to the interpretation of breast MRI examinations. With these advances in imaging technique, interpretation guidelines, and increasing availability of MR-compatible breast biopsy systems, MRI of the breast is rapidly gaining popularity in clinical practice in both the diagnostic setting and, more recently, in the screening setting. The clinical indications for breast MRI, however, remain to be defined. There are clinical indications that have emerged where MRI, as an adjunct to mammography, seems to be the imaging study of choice. There are other indications, specifically breast cancer staging, in which MRI is being utilized with increasing frequency, but in which controversy persists.

The role of breast MRI in the management of patients with breast disease

Breast MRI has paved the way for new thinking regarding the workup of women recently diagnosed with breast cancer and the screening of high-risk women. The routine use of MRI preoperatively is advocated, particularly in young patients and women with dense breasts where mammography is significantly less sensitive for the detection of malignancy. Additionally, MRI is particularly helpful in those women who have core biopsy results showing extensive intraductal component (>25%) orinvasive lobular carcinoma, and in those women with increased risk of positive margins. However, as with any imaging modality, breast magnetic resonance has limitations. Because breast magnetic resonance has lower specificity than some modalities, clinicians must be selective in identifying those women most likely to benefit from this additional imaging. Many recent publications show that MRI does not unduly raise the false-positive biopsy rate while providing specificity similar to that of mammography and higher than that of ultrasound. Positive margin rates for breast conservation therapy range from 30% to 50% and the achievement of negative margins is directly related to low recurrence rates. Magnetic resonance provides improved preoperative staging, which in turn may reduce recurrence rates and improve patient outcome. Breast MRI should be used in concert with other modalities, such as mammography and ultrasound, for the highest sensitivity for detecting malignancy. Long-term studies are needed to validate the impact of screening and diagnostic breast MRI on patient outcomes.

Treatment of hereditary breast cancer

Mutations in BRCA1 and BRCA2 are well-established causes of hereditary breast cancer. As genetic testing becomes more widespread, increasing numbers of women are known to have mutations at or shortly after their breast cancer diagnosis. Current evidence is insufficient to mandate different local or systemic treatment based upon the presence of a germline mutation. The well-documented increased risk of contralateral second primary breast cancer and possibly of late ipsilateral second primary breast cancers may influence patient decision-making with regard to breast-conserving treatment.

Beyond standard mammographic screening: mammography at age extremes, ultrasound, and MR imaging

This article describes the principles and performance of screening mammography and discusses indications for screening before the age of 40 years and after the age of 69 years. Specific definitions of high risk are provided, and the rationale and performance characteristics to dare of supplemental screening with ultrasound or MR imaging are reviewed.

Magnetic resonance imaging of the breast improves detection of invasive cancer, preinvasive cancer, and premalignant lesions during surveillance of women at high risk for breast cancer

PURPOSE

To assess the diagnostic accuracy of mammography, ultrasound, and magnetic resonance imaging (MRI) of the breast in the surveillance of women at high risk for breast cancer.

EXPERIMENTAL DESIGN

In this prospective comparison study, women at high risk for breast cancer were offered annual surveillance examinations, consisting of mammography, ultrasound, and MRI, at a single tertiary care breast center. The sensitivity and specificity of each modality was based on the histopathologic evaluation of suspicious findings from all modalities plus the detected interval cancers.

RESULTS

Three hundred and twenty-seven women underwent 672 complete imaging rounds. Of a total of 28 detected cancers, 14 were detected by mammography, 12 by ultrasound, and 24 by MRI, which resulted in sensitivities of 50%, 42.9%, and 85.7%, respectively (P < 0.01). MRI detected not only significantly more invasive but also significantly more preinvasive cancers (ductal carcinoma in situ). Mammography, ultrasound, and MRI led to 25, 26, and 101 false-positive findings, which resulted in specificities of 98%, 98%, and 92%, respectively (P < 0.05). Thirty-five (35%) of these false-positive findings were atypical ductal hyperplasias, lesions considered to be of premalignant character. Nine (26%) of those were detected by mammography, 2 (6%) with ultrasound, and 32 (91%) with MRI (P < 0.01).

CONCLUSION

Our results show that MRI of the breast improves the detection of invasive cancers, preinvasive cancers, and premalignant lesions in a high-risk population and should therefore become an integral part of breast cancer surveillance in these patients.

Current Status of Breast MR Imaging Part 2. Clinical Applications

Magnetic resonance (MR) imaging is emerging as the most sensitive modality that is currently available for the detection of primary or recurrent breast cancer. Although this technique has been shown to be an extremely powerful diagnostic tool, it is still relatively rarely used in clinical practice, as compared with other applications of MR imaging such as for musculoskeletal or brain and spine imaging. This is the second of a two-part series on the current status of breast MR. Part two provides an overview of the use of breast MR imaging in clinical patient care, the body of evidence that supports its use. A discussion is provided on the many controversies that exist regarding breast MR imaging for preoperative staging and for screening.

Outcome of initially only magnetic resonance mammography-detected findings with and without correlate at second-look sonography: distribution according to patient history of breast cancer and lesion size

The purpose of the study was to evaluate the outcome of initially only magnetic resonance mammography (MRM)-detected breast lesions as a function of radiologic features, history of breast cancer and lesion size. We evaluated core needle biopsy (CNB) (148) and follow-up (25) results of 173 initially only MRM-detected lesions-142 with and 31 without "second-look" correlate, as a function of (1) radiologic features (sonographic correlate, MRI BI-RADS category); (2) history of breast cancer; (3) MRM indication in case of history of breast neoplasm; (4) side and size of synchronous cancer; (5) lesion diameter. (1) Overall malignancy rate was 28.3% (49/173); significantly higher among lesions with a sonographic correlate (46/142), than among those without (3/31) (p=0.014). Frequencies of malignancy for MRI BI-RADS categories 2, 3, 4 and 5, were 0% (0/1), 5.4% (4/73), 26.1% (17/65) and 82.3% (28/34), respectively. (2) Malignancy rate was significantly higher in case of history of breast carcinoma (40/118 versus 9/55; p=0.027); in particular, of 42 MRI BI-RADS category 3 lesions in women with history of breast cancer and of 31 in patients without history, 3 (7%) and 1 (3%) proved to be malignant, respectively (non-significant). (3) Malignancy was more frequent when MRM was performed for pre-operative assessment than for follow-up (30/78 versus 10/40; non-significant). (4) Malignancy rate increased in presence of ipsilateral (19/35 versus 11/43; p=0.018), large (cut-off 6 mm: 30/75 versus 0/3, non-significant; 11 mm: 28/61 versus 2/17, p=0.011; 16 mm: 24/48 versus 6/30, p=0.015; 21 mm: 14/21 versus 16/57, p=0.004) primary tumors. (5) The frequency of malignancy was significantly higher in lesions equal to or larger than 6, 11 and 16 mm, compared with smaller lesions (6 mm: 45/136 versus 4/37, p=0.007; 11 mm: 21/51 versus 28/122, p=0.025; 16 mm: 12/24 versus 37/149, p=0.021). Radiologic features, history of breast cancer and large diameter are associated with high likelihood of malignancy in case of initially only MRM-detected lesions. Nevertheless, biopsy might be spared just for MRI BI-RADS 3 lesions in patients without history of breast carcinoma.

MRI for diagnosis of pure ductal carcinoma in situ: a prospective observational study

BACKGROUND

Diagnosing breast cancer in its intraductal stage might be helpful to prevent the development of invasive cancer. Our aim was to investigate the sensitivity with which ductal carcinoma in situ (DCIS) is diagnosed by mammography and by breast MRI.

METHODS

During a 5-year period, 7319 women who were referred to an academic national breast centre received MRI in addition to mammography for diagnostic assessment and screening. Mammograms and breast MRI studies were assessed independently by different radiologists. We investigated the sensitivity of each method of detection and compared the biological profiles of mammography-diagnosed DCIS versus DCIS detected by MRI alone. We also compared the risk profiles of women with mammography-detected DCIS with those of MRI-detected DCIS.

FINDINGS

193 women received a final surgical pathology diagnosis of pure DCIS. Of those, 167 had undergone both imaging tests preoperatively. 93 (56%) of these cases were diagnosed by mammography and 153 (92%) by MRI (p<0.0001). Of the 89 high-grade DCIS, 43 (48%) were missed by mammography, but diagnosed by MRI alone; all 43 cases missed by mammography were detected by MRI. By contrast, MRI detected 87 (98%) of these lesions; the two cases missed by MRI were detected by mammography. Age, menopausal status, personal or family history of breast cancer or of benign breast disease, and breast density of women with MRI-only diagnosed DCIS did not differ significantly from those of women with mammography-diagnosed DCIS.

INTERPRETATION

MRI could help improve the ability to diagnose DCIS, especially DCIS with high nuclear grade.

A systematic review of the effectiveness of magnetic resonance imaging (MRI) as an addition to mammography and ultrasound in screening young women at high risk of breast cancer

Breast magnetic resonance imaging (MRI) has been proposed as an additional screening test for young women at high risk of breast cancer in whom mammography alone has poor sensitivity. We conducted a systematic review to assess the effectiveness of adding MRI to mammography with or without breast ultrasound and clinical breast examination (CBE) in screening this population. We found consistent evidence in 5 studies that adding MRI provides a highly sensitive screening strategy (sensitivity range: 93-100%) compared to mammography alone (25-59%) or mammography plus ultrasound+/-CBE (49-67%). Meta-analysis of the three studies that compared MRI plus mammography versus mammography alone showed the sensitivity of MRI plus mammography as 94% (95%CI 86-98%) and the incremental sensitivity of MRI as 58% (95%CI 47-70%). Incremental sensitivity of MRI was lower when added to mammography plus ultrasound (44%, 95%CI 27-61%) or to the combination of mammography, ultrasound plus CBE (31-33%). Estimates of screening specificity with MRI were less consistent but suggested a 3-5-fold higher risk of patient recall for investigation of false positive results. No studies assessed as to whether adding MRI reduces patient mortality, interval or advanced breast cancer rates, and we did not find strong evidence that MRI leads to the detection of earlier stage disease. Conclusions about the effectiveness of MRI therefore depend on assumptions about the benefits of early detection from trials of mammographic screening in older average risk populations. The extent to which high risk younger women receive the same benefits from early detection and treatment of MRI-detected cancers has not yet been established.