Differences between first and subsequent rounds of the MRISC breast cancer screening program for women with a familial or genetic predisposition

MRI and mammography surveillance of women at increased risk for breast cancer: recommendations using an evidence-based approach

RATIONALE AND OBJECTIVES

To evaluate breast cancer screening with mammography and magnetic resonance imaging (MRI) in high-risk populations, including women with the BRCA mutation, using an evidence-based approach.

METHODS

The MEDLINE, PubMed, EBM Reviews, ACP Journal Club, Cochrane Database MEDSEARCH, and SCOPUS databases were accessed and searched for articles up to August 2007. Articles were collected using the following terms and medical subject headings (MeSH) that applied to the focused clinical question: "BRCA1" and "BRCA2" with "mammography," "MRI," "prevention," "screening," and "surveillance." References from retrieved articles were also used to identify relevant papers. Abstracts were screened and relevant papers retrieved. Retrieved papers were graded for quality. Summary performance measures were obtained by random effects modeling of study-specific performance estimates and standard errors derived from the multiple 2 x 2 tables. Additionally, studies meeting the Centre for Evidence-Based Medicine level 2b quality were reviewed.

RESULTS

In women with an increased risk without the BRCA gene, cancer detection rates by MRI were 0.011 (95% confidence interval [CI] 0.003-0.019), by mammography 0.005 (95% CI 0.002-0.008), and by a combination of both, 0.012 (95% CI 0.004-0.020). False-positive rates by MRI, mammography, or a combination of both were 0.10 (95% CI 0.03-0.18), 0.05 (95% CI 0.03-0.06), and 0.14 (95% CI 0.04-0.24). In BRCA positive women, cancer detection rates by MRI were 0.027 (95% CI 0.015-0.040), by mammography 0.010 (95% CI 0.005-0.016), and by a combination of both 0.031 (95% CI 0.018-0.045). False-positive rates by MRI, mammography, or a combination of both were 0.10 (95% CI 0.01-0.19), 0.05 (95% CI 0.03-0.07), and 0.14 (95% CI 0.04-0.24), respectively.

CONCLUSIONS

The data support an essential role for screening MRI in women with an increased risk for breast cancer.

[Does breast density have an impact on the indications for MRI?]

MRI indications in breast imaging in breast imaging are now well codified. In diagnostic and screening, MRI in recommended in patients with likely metastatic lymph nodes and in metastasis of unknown cause, and in women with high risk family. In characterisation MRI is recommend in non-calcified subtle findings, non suitable for biopsy. In the staging of a diagnosed breast cancer, MRI has a great impact both for the diagnosis and for the treatment, event if group of women for whom MRI is recommended is still discussed. In follow-up of patients with an history of breast cancer, MRI permits to differentiate recurrence from scarr and to monitor the response to a neo-adjuvant chemotherapy. Dense breast don't constitute a MRI indication by itself, but strengthen recognized MRI indications. Fatty breast easily readable on mammogram don't justify not to perform MRI in the screening of women with high risk family. Conservely in the staging of a breast cancer in an woman or in the monitoring of a neo-adjuvant chemotherapy fatty breast may make US sufficient.

Magnetic resonance imaging--guided breast interventions

The use of breast magnetic resonance imaging (MRI) for screening, diagnosis, staging, and management of breast cancer is rapidly increasing. MRI is highly sensitive for the detection of benign and malignant abnormalities that are occult to physical examination, ultrasound, and mammography. However, the specificity of MRI is moderate. These attributes necessitate methods for MR-guided tissue sampling to determine the histology of MRI detected lesions. This article will review appropriate peer-reviewed data and currently accepted methods for MR-guided tissue sampling. A detailed step-by-step technique for vacuum-assisted MR-guided breast biopsy is included. We also review emerging data for percutaneous and transcutaneous MR-guided breast interventions such as tissue ablation for benign and malignant disease.

Screening for hereditary breast cancer

Most women at risk for hereditary breast cancer opt for intensive breast screening rather than risk-reducing mastectomy. For this to be a rational choice, the vast majority of tumors must be detected either while still in situ or at a very early stage of invasion. Annual screening mammography has low sensitivity in this population, in part due to the greater breast density of younger women, resulting in cancers being detected at a suboptimal stage. In six prospective comparative studies, the addition of annual contrast-enhanced magnetic resonance imaging (MRI) of the breast to mammography demonstrated greater than 90% sensitivity, more than twice that of mammography alone. In those studies that included ultrasound and clinical breast examination, additional cancers were rarely detected by these modalities. False positive rates were higher with the addition of MRI, but specificity improved on successive rounds of screening. Although long-term survival data are still lacking, there is mounting evidence that the addition of screening MRI to mammography detects hereditary breast cancers at an earlier stage and is thus estimated to be cost-effective, at least for women with BRCA mutations. This review will examine the literature and current screening recommendations.

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.

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.

Dynamic breast MR imaging: is parametric mapping superior to image subtraction in lesion detection?

We compared the detection of malignant lesions in two different methods of parametric-guided analysis to the widely used early subtraction images. The parametric colour-coded overlays were defined by the increase of signal intensity after contrast injection and the course of the time signal intensity curve. Exams of 30 patients with histopathological evidence of 32 invasive breast carcinomas were evaluated. Five hundred five areas of additional enhancing tissue were found in the early subtraction images. The sensitivity was 100 in the subtraction images and 100 and 93.8 in the parametric images, respectively, the specificity 67.5, 84.2 and 88.7, respectively. On average 4.4 ROI-measurements were needed to find the highest increase of signal intensity in the subtraction series compared to 1.9 in the parametric images. Properly selected thresholds in parametric imaging may be helpful in the differentiation of enhancing tissue. Furthermore the parametric image-guided ROI selection significantly speeds up the analysis and makes it safer as a lower rate of ROI-measurements is needed to find the strongest enhancement.

Imaging breast cancer

Imaging has a significant role in diagnosing, treating, and monitoring breast cancer. Advances in this field are having a great impact in the clinical management of this disease. Breast cancer has now become an "outpatient cancer". This article describes the role and advances of imaging in breast cancer.

Factors Affecting Sensitivity and Specificity of Screening Mammography and MRI in Women with an Inherited Risk for Breast Cancer

BACKGROUND

The MRISC study is a screening study, in which women with an increased risk of hereditary breast cancer are screened by a yearly mammography and MRI, and half-yearly clinical breast examination. The sensitivity found in this study was 40% for mammography and 71% for MRI and the specificity was 95 and 90%, respectively. In the current subsequent study we investigated whether these results are influenced by age, a BRCA1/2 mutation, menopausal status and breast density.

PATIENTS AND METHODS

From November 1999 to October 2003, 1909 eligible women were screened and 50 breast cancers were detected. For the current analysis, data of 4134 screening rounds and 45 detected breast cancers were used. For both imaging modalities, screening parameters, receiver operating characteristic (ROC) curves and uni- and multivariate odds ratios (ORs) were calculated. All analyses were separately performed for age at entry (< 40, 40-49, > or =50), mutation status, menopausal status and breast density.

RESULTS

Sensitivity of MRI was decreased in women with high breast density (adjusted OR 0.08). False-positive rates of both mammography (OR(adj) 1.67) and MRI (OR(adj) 1.21) were increased by high breast density, that of MRI by pre-menopausal status (OR(adj) 1.70), young age (OR(adj) 1.58 for women 40-49 years versus women > or =50 years) and decreased in BRCA1/2 mutation carriers (OR(adj) 0.74). In all investigated subgroups the discriminating capacity (measured by the area under the ROC-curve) was higher for MRI than for mammography, with the largest differences for BRCA1/2 mutation carriers (0.237), for women between 40 and 49 years (0.227) and for women with a low breast density (0.237).

CONCLUSIONS

This report supports the earlier recommendation that MRI should be a standard screening method for breast cancer in BRCA1/2 mutation carriers.