Screening with magnetic resonance imaging and mammography of a UK population at high familial risk of breast cancer: a prospective multicentre cohort study (MARIBS)

Magnetic resonance imaging for screening, diagnosis, and eligibility for breast-conserving surgery: promises and pitfalls

Magnetic resonance imaging (MRI) is able to visualize small tumor deposits that previously could only be identified on pathologic examination. MRI is most valuable in areas in which patient management has been problematic, including screening women with known or suspected BRCA 1 and 2 mutations, and identification of the primary tumor site in patients presenting with axillary adenopathy. The role of MRI in the patient with newly diagnosed breast cancer remains controversial. Success rates for patients selected for breast-conserving therapy without MRI are high, and rates of ipsilateral breast tumor recurrence are low. Future efforts to improve the local therapy for breast cancer must acknowledge the heterogeneity of the disease and tailor approaches to the biology of individual subsets. This goal can only be accomplished through a multidisciplinary approach that examines the applications of newer diagnostic modalities such as MRI.

Breast cancer screening with imaging: recommendations from the Society of Breast Imaging and the ACR on the use of mammography, breast MRI, breast ultrasound, and other technologies for the detection of clinically occult breast cancer

Screening for breast cancer with mammography has been shown to decrease mortality from breast cancer, and mammography is the mainstay of screening for clinically occult disease. Mammography, however, has well-recognized limitations, and recently, other imaging including ultrasound and magnetic resonance imaging have been used as adjunctive screening tools, mainly for women who may be at increased risk for the development of breast cancer. The Society of Breast Imaging and the Breast Imaging Commission of the ACR are issuing these recommendations to provide guidance to patients and clinicians on the use of imaging to screen for breast cancer. Wherever possible, the recommendations are based on available evidence. Where evidence is lacking, the recommendations are based on consensus opinions of the fellows and executive committee of the Society of Breast Imaging and the members of the Breast Imaging Commission of the ACR.

Cost-effectiveness of breast MR imaging and screen-film mammography for screening BRCA1 gene mutation carriers

PURPOSE

To evaluate the clinical effectiveness and cost-effectiveness of screening strategies in which MR imaging and screen-film mammography were used, alone and in combination, in women with BRCA1 mutations.

MATERIALS AND METHODS

Because this study did not involve primary data collection from individual patients, institutional review board approval was not needed. By using a simulation model, we compared three annual screening strategies for a cohort of 25-year-old BRCA1 mutation carriers, as follows: (a) screen-film mammography, (b) MR imaging, and (c) combined MR imaging and screen-film mammography (combined screening). The model was used to estimate quality-adjusted life-years (QALYs) and lifetime costs. Incremental cost-effectiveness ratios were calculated. Input parameters were obtained from the medical literature, existing databases, and calibration. Costs (2007 U.S. dollars) and quality-of-life adjustments were derived from Medicare reimbursement rates and the medical literature. Sensitivity analysis was performed to evaluate the effect of uncertainty in parameter estimates on model results.

RESULTS

In the base-case analysis, annual combined screening was most effective (44.62 QALYs), and had the highest cost ($110973), followed by annual MR imaging alone (44.50 QALYs, $108641), and annual mammography alone (44.46 QALYs, $100336). Adding annual MR imaging to annual mammographic screening cost $69125 for each additional QALY gained. Sensitivity analysis indicated that, when the screening MR imaging cost increased to $960 (base case, $577), or breast cancer risk by age 70 years decreased below 58% (base case, 65%), or the sensitivity of combined screening decreased below 76% (base case, 94%), the cost of adding MR imaging to mammography exceeded $100000 per QALY.

CONCLUSION

Annual combined screening provides the greatest life expectancy and is likely cost-effective when the value placed on gaining an additional QALY is in the range of $50000-$100000.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09091086/-/DC1.

Magnetic resonance imaging of the breast: recommendations from the EUSOMA working group

The use of breast magnetic resonance imaging (MRI) is rapidly increasing. EUSOMA organised a workshop in Milan on 20-21st October 2008 to evaluate the evidence currently available on clinical value and indications for breast MRI. Twenty-three experts from the disciplines involved in breast disease management - including epidemiologists, geneticists, oncologists, radiologists, radiation oncologists, and surgeons - discussed the evidence for the use of this technology in plenary and focused sessions. This paper presents the consensus reached by this working group. General recommendations, technical requirements, methodology, and interpretation were firstly considered. For the following ten indications, an overview of the evidence, a list of recommendations, and a number of research issues were defined: staging before treatment planning; screening of high-risk women; evaluation of response to neoadjuvant chemotherapy; patients with breast augmentation or reconstruction; occult primary breast cancer; breast cancer recurrence; nipple discharge; characterisation of equivocal findings at conventional imaging; inflammatory breast cancer; and male breast. The working group strongly suggests that all breast cancer specialists cooperate for an optimal clinical use of this emerging technology and for future research, focusing on patient outcome as primary end-point.

Breast cancer risks in individuals testing negative for a known family mutation in BRCA1 or BRCA2

Genetic testing for BRCA1 and BRCA2 mutations in family members of individuals with known deleterious mutations can distinguish between patients at high risk of disease and those who are not. Some studies have suggested that individuals testing negative for known familial mutations (true negatives), may still have a higher risk of breast cancer (BC) than the general population. We have examined a prospectively followed cohort of true negative women in the US. Subjects were close relatives of known BRCA1 and BRCA2 mutation carriers who had undergone genetic testing, were negative for the known familial mutation, and were unaffected at the time of genetic testing. Standardized incidence ratios (SIR) and 95% confidence intervals (CI) were calculated using SEER incidence rates. Among 375 true negatives, two invasive and two in situ BC and no ovarian cancers were diagnosed with mean follow up of 4.9 years (total of 1,962 person years).Four invasive BC were expected, whereas two were observed, for an age-adjusted SIR of 0.52 (95% CI 0.13-2.09). We observed more cases of in situ BC (n = 2) than were expected (n = 0.9; SIR = 2.30; 95% CI 0.57-9.19).There were no cases of ovarian cancer observed; 0.4 case was expected. In this prospective study of women who were unaffected at the time of genetic testing and who were negative for the known familial mutation in BRCA1/2, no excess risk of invasive BC was observed. Our data suggest that such women in the US should adhere to population based guidelines for breast cancer screening.

Breast cancer detection using automated whole breast ultrasound and mammography in radiographically dense breasts

PURPOSE

Mammography, the standard method of breast cancer screening, misses many cancers, especially in dense-breasted women. We compared the performance and diagnostic yield of mammography alone versus an automated whole breast ultrasound (AWBU) plus mammography in women with dense breasts and/or at elevated risk of breast cancer.

METHODS

AWBU screening was tested in 4,419 women having routine mammography (

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00649337). Cancers occurring during the study and subsequent 1-year follow-up were evaluated. Sensitivity, specificity and positive predictive value (PPV) of biopsy recommendation for mammography alone, AWBU and mammography with AWBU were calculated.

RESULTS

Breast cancer detection doubled from 23 to 46 in 6,425 studies using AWBU with mammography, resulting in an increase in diagnostic yield from 3.6 per 1,000 with mammography alone to 7.2 per 1,000 by adding AWBU. PPV for biopsy based on mammography findings was 39.0% and for AWBU 38.4%. The number of detected invasive cancers 10 mm or less in size tripled from 7 to 21 when AWBU findings were added to mammography.

CONCLUSION

AWBU resulted in significant cancer detection improvement compared with mammography alone. Additional detection and the smaller size of invasive cancers may justify this technology's expense for women with dense breasts and/or at high risk for breast cancer.

Diagnostic breast MR imaging: current status and future directions

Breast MRI has become an integral component in breast imaging. Indications have become clearer and better defined. Guidelines and recommendations are evolving and many are recognized and published. Future applications are exciting and may possibly improve our ability to diagnose breast cancer, improving the patient's treatment options and ultimately patient outcome.

Prospective multicenter cohort study to refine management recommendations for women at elevated familial risk of breast cancer: the EVA trial

PURPOSE

We investigated the respective contribution (in terms of cancer yield and stage at diagnosis) of clinical breast examination (CBE), mammography, ultrasound, and quality-assured breast magnetic resonance imaging (MRI), used alone or in different combination, for screening women at elevated risk for breast cancer.

METHODS

Prospective multicenter observational cohort study. Six hundred eighty-seven asymptomatic women at elevated familial risk (> or = 20% lifetime) underwent 1,679 annual screening rounds consisting of CBE, mammography, ultrasound, and MRI, read independently and in different combinations. In a subgroup of 371 women, additional half-yearly ultrasound and CBE was performed more than 869 screening rounds. Mean and median follow-up was 29.18 and 29.09 months.

RESULTS

Twenty-seven women were diagnosed with breast cancer: 11 ductal carcinoma in situ (41%) and 16 invasive cancers (59%). Three (11%) of 27 were node positive. All cancers were detected during annual screening; no interval cancer occurred; no cancer was identified during half-yearly ultrasound. The cancer yield of ultrasound (6.0 of 1,000) and mammography (5.4 of 1,000) was equivalent; it increased nonsignificantly (7.7 of 1,000) if both methods were combined. Cancer yield achieved by MRI alone (14.9 of 1,000) was significantly higher; it was not significantly improved by adding mammography (MRI plus mammography: 16.0 of 1,000) and did not change by adding ultrasound (MRI plus ultrasound: 14.9 of 1,000). Positive predictive value was 39% for mammography, 36% for ultrasound, and 48% for MRI.

CONCLUSION

In women at elevated familial risk, quality-assured MRI screening shifts the distribution of screen-detected breast cancers toward the preinvasive stage. In women undergoing quality-assured MRI annually, neither mammography, nor annual or half-yearly ultrasound or CBE will add to the cancer yield achieved by MRI alone.

Vacuum-assisted biopsies under MR guidance: results of 72 procedures

OBJECTIVE

To investigate the clinical accuracy of magnetic resonance imaging-guided breast vacuum-assisted biopsy (MR-VAB).

METHODS

Of 97 scheduled MR-VAB for single MRI lesions (negative second-look sonography) categorised as BI-RADS 4 or 5, 4 were cancelled (undetected lesion = 2, technical problems = 2). Twenty-one patients lost to follow-up were excluded.

RESULTS

Twenty-three patients (median age 51 years) were at high risk (BRCA1 = 11, BRCA2 = 7, familial risk = 5), 23 had a suspected local recurrence of breast cancer. Seventy-two imaged lesions (focus = 1, mass enhancement = 32, non-mass-like enhancement = 39) were targeted with a 10-gauge VAB probe using MRI guidance, with a median of 18 specimens per lesion (median procedural time 72 min, range 50-131 min) followed by clip placement. In the case of benignity, MRI follow-up was performed (19 patients, median 389 days, range 33-1,592) or mammography (3 patients, median 420 days, range 372-1,354). According to histopathology results, 29 lesions were benign, 10 were high-risk (papillary = 2, radial scar = 1, atypical epithelial hyperplasia = 7) and 33 malignant (ductal carcinoma in situ = 8, invasive cancers = 25). Three false negative results and 3 complications occurred (1 malaise, 1 skin defect, 1 infection).

CONCLUSION

MRI-guided VAB represents an accurate tool for the histological diagnosis of lesions visible only at MRI.

Independent slab-phase modulation combined with parallel imaging in bilateral breast MRI

Independent slab-phase modulation allows three-dimensional imaging of multiple volumes without encoding the space between volumes, thus reducing scan time. Parallel imaging further accelerates data acquisition by exploiting coil sensitivity differences between volumes. This work compared bilateral breast image quality from self-calibrated parallel imaging reconstruction methods such as modified sensitivity encoding, generalized autocalibrating partially parallel acquisitions and autocalibrated reconstruction for Cartesian sampling (ARC) for data with and without slab-phase modulation. A study showed an improvement of image quality by incorporating slab-phase modulation. Geometry factors measured from phantom images were more homogenous and lower on average when slab-phase modulation was used for both mSENSE and GRAPPA reconstructions. The resulting improved signal-to-noise ratio (SNR) was validated for in vivo images as well using ARC instead of GRAPPA, illustrating average SNR efficiency increases in mSENSE by 5% and ARC by 8% based on region of interest analysis. Furthermore, aliasing artifacts from mSENSE reconstruction were reduced when slab-phase modulation was used. Overall, slab-phase modulation with parallel imaging improved image quality and efficiency for 3D bilateral breast imaging.

A high spatial resolution in vivo 1H magnetic resonance spectroscopic imaging technique for the human breast at 3 T

PURPOSE

The technical challenges that have prevented routine proton magnetic resonance spectroscopic imaging (1H MRSI) examinations of the breast include insufficient spatial resolution, increased difficulties in shimming compared to the brain, and strong lipid contamination at short echo time (TE) at 1.5 T. The authors investigated the feasibility of high spatial resolution 1H MRSI of human breast cancer in a clinical setting at 3 T.

METHODS

Ten patient studies (eight cancers and two benign lesions) were performed in a 3 T whole-body clinical imager using a pulse sequence consisting of optional outer volume presaturation, optional CHESS pulse for lipid suppression, CHESS pulse for water suppression, and standard 2D/3D PRESS pulse sequence with an elliptical weighted k-space sampling scheme.

RESULTS

All ten studies were technically successful. The spectral quality was acceptable for all cases even the one with a 65 Hz width of water peak at half height. Choline (Cho) signals were clearly visible in malignant lesion areas, while there was no detectable Cho in normal appearing breast or in benign lesions. It was also observed that the distribution of Cho signal can be nonuniform across MRI demonstrated lesions.

CONCLUSIONS

To the author's knowledge, this is the first 2D/3D MRSI study of human breast cancer with short TE (less than 135 ms) at 3 T and the highest spatial resolution (up to 0.25 cm3) to date. In conclusion, the authors have presented a robust technique for high spatial resolution in vivo 1H MRSI of human breast cancer that uses the combined advantages of high field, short TE, multivoxel, and high spatial resolution itself to overcome the major technical challenges and illustrated its potential for routine clinical examination as well as advantages over single-voxel techniques in studying metabolite heterogeneity.

Relating dose of contrast media administered to uptake and washout of malignant lesions on DCEMRI of the breast

RATIONALE AND OBJECTIVES

To quantify the relationship between dose of contrast administered and contrast kinetics of malignant breast lesions.

MATERIALS AND METHODS

A total of 108 patients with 120 malignant lesions were selected for an institutional review board-approved review. Dynamic magnetic resonance protocol: one pre- and three or five post-contrast (at a fixed volume of 20 mL of 0.5 M gadodiamide) images. Patients were stratified into groups based on dose of contrast administered, after calculation of body weight (kg): Dose Group 1, <0.122 mmol/kg; Dose Group 2, 0.123-0.155 mmol/kg; Dose Group, 3 > 0.155 mmol/kg. Analysis of kinetic curve shape was made according to the Breast Imaging Reporting and Data System lexicon. Several quantitative parameters were calculated including initial and peak enhancement percentage (E(1) and E(peak)). Linear regression was used to model the variation of kinetic parameters with dose.

RESULTS

There was no difference found in the qualitative Breast Imaging Reporting and Data System descriptors of curve shape between the three dose groups. There was a trend for E(1) and E(peak) to increase from Dose Group 1 to Dose Group 3 in malignant lesions overall, as well as in invasive ductal carcinoma lesions separately. Each decrement/increment of 0.05 mmol/kg in dose yielded a decrease/increase of 78% and 97% in E(1) for in situ and invasive cancers, respectively.

CONCLUSION

Contrast should be administered at fixed dose to achieve comparable levels of lesion uptake in women of different weights. Our results suggest that reducing the contrast administered to 0.05 mmol/kg, as has been suggested for patients at risk of developing nephrogenic systemic fibrosis, could substantially decrease the observed initial enhancement in some cancers.

Magnetic resonance imaging in the evaluation of ductal carcinoma in situ

Before 2000, breast magnetic resonance imaging (MRI) was considered a relatively poor imaging tool for ductal carcinoma in situ (DCIS), as a high percentage of false-negative magnetic resonance examinations were cases of DCIS. Three specific shifts in breast MRI occurred, which changed this assessment: 1) a shift from high temporal to high spatial imaging, revealing specific morphological features on MRI suspicious for DCIS; 2) a shift from diagnostic studies of patients with cancers identified on mammography to screening studies of high-risk patients, allowing more accurate comparisons of mammography vs MRI in detecting the full spectrum of breast cancers regardless of appearance on mammography; and 3) a shift from emphasis on masses to improved understanding of features of non-mass-like malignant lesions, distinct from benign background parenchymal enhancement patterns. Over the last decade, research has confirmed that of all imaging tools, MRI has the highest sensitivity in detection of DCIS (compared with mammography and ultrasound). Future studies are needed to clarify how best to use this tool for improved patient outcomes.

Survival analysis of cancer risk reduction strategies for BRCA1/2 mutation carriers

PURPOSE

Women with BRCA1/2 mutations inherit high risks of breast and ovarian cancer; options to reduce cancer mortality include prophylactic surgery or breast screening, but their efficacy has never been empirically compared. We used decision analysis to simulate risk-reducing strategies in BRCA1/2 mutation carriers and to compare resulting survival probability and causes of death.

METHODS

We developed a Monte Carlo model of breast screening with annual mammography plus magnetic resonance imaging (MRI) from ages 25 to 69 years, prophylactic mastectomy (PM) at various ages, and/or prophylactic oophorectomy (PO) at ages 40 or 50 years in 25-year-old BRCA1/2 mutation carriers.

RESULTS

With no intervention, survival probability by age 70 is 53% for BRCA1 and 71% for BRCA2 mutation carriers. The most effective single intervention for BRCA1 mutation carriers is PO at age 40, yielding a 15% absolute survival gain; for BRCA2 mutation carriers, the most effective single intervention is PM, yielding a 7% survival gain if performed at age 40 years. The combination of PM and PO at age 40 improves survival more than any single intervention, yielding 24% survival gain for BRCA1 and 11% for BRCA2 mutation carriers. PM at age 25 instead of age 40 offers minimal incremental benefit (1% to 2%); substituting screening for PM yields a similarly minimal decrement in survival (2% to 3%).

CONCLUSION

Although PM at age 25 plus PO at age 40 years maximizes survival probability, substituting mammography plus MRI screening for PM seems to offer comparable survival. These results may guide women with BRCA1/2 mutations in their choices between prophylactic surgery and breast screening.

Sensitivity and specificity of unenhanced MR mammography (DWI combined with T2-weighted TSE imaging, ueMRM) for the differentiation of mass lesions

OBJECTIVE

This study was performed to assess the sensitivity and specificity for malignant and benign mass lesions of a diagnostic approach combining DWI with T2-weighted images (unenhanced MR mammography, ueMRM) and compare the results with contrast-enhanced MR mammography (ceMRM).

MATERIALS AND METHODS

Consecutive patients undergoing histopathological verification of mass lesions after MR mammography without prior breast interventions (contrast-enhanced T1-weighted, T2-weighted and DWI sequences) were eligible for this retrospective investigation. Two blinded observers first rated ueMRM and then ceMRM according to the BIRADS scale. Lesion size, ADC values and T2-weighted TSE descriptors were assessed.

RESULTS

This study examined 81 lesions (27 benign, 54 malignant). Sensitivity of ueMRM was 93% (observer 1) and 86% (observer 2), respectively. Sensitivity of ceMRM was 96.5% (observer 1) and 98.3% (observer 2). Specificity was 85.2% (ueMRM) and 92.6% (ceMRM) for both observers. The differences between both methods and observers were not significant (P > or = 0.09). Lesion size measurements did not differ significantly among all sequences analyzed. Tumor visibility was worse using ueMRM for both benign (P < 0.001) and malignant lesions (P = 0.004).

CONCLUSION

Sensitivity and specificity of ueMRM in mass lesions equal that of ceMRM. However, a reduced lesion visibility in ueMRM may lead to more false-negative findings.

Assessing the usefulness of a novel MRI-based breast density estimation algorithm in a cohort of women at high genetic risk of breast cancer: the UK MARIBS study

Introduction

Mammographic breast density is one of the strongest known risk factors for breast cancer. We present a novel technique for estimating breast density based on 3D T1-weighted Magnetic Resonance Imaging (MRI) and evaluate its performance, including for breast cancer risk prediction, relative to two standard mammographic density-estimation methods.

Methods

The analyses were based on MRI (n = 655) and mammography (n = 607) images obtained in the course of the UK multicentre magnetic resonance imaging breast screening (MARIBS) study of asymptomatic women aged 31 to 49 years who were at high genetic risk of breast cancer. The MRI percent and absolute dense volumes were estimated using our novel algorithm (MRIBview) while mammographic percent and absolute dense area were estimated using the Cumulus thresholding algorithm and also using a 21-point Visual Assessment scale for one medio-lateral oblique image per woman. We assessed the relationships of the MRI and mammographic measures to one another, to standard anthropometric and hormonal factors, to BRCA1/2 genetic status, and to breast cancer risk (60 cases) using linear and Poisson regression.

Results

MRI percent dense volume is well correlated with mammographic percent dense area (R = 0.76) but overall gives estimates 8.1 percentage points lower (P < 0.0001). Both show strong associations with established anthropometric and hormonal factors. Mammographic percent dense area, and to a lesser extent MRI percent dense volume were lower in BRCA1 carriers (P = 0.001, P = 0.010 respectively) but there was no association with BRCA2 carrier status. The study was underpowered to detect expected associations between percent density and breast cancer, but women with absolute MRI dense volume in the upper half of the distribution had double the risk of those in the lower half (P = 0.009).

Conclusions

The MRIBview estimates of volumetric breast density are highly correlated with mammographic dense area but are not equivalent measures; the MRI absolute dense volume shows potential as a predictor of breast cancer risk that merits further investigation.

Multimodality screening of high-risk women: a prospective cohort study

PURPOSE

Mammography has been established as the primary imaging screening method for breast cancer; however, the sensitivity of mammography is limited, especially in women with dense breast tissue. Given the limitations of mammography, interest has developed in alternative screening techniques. This interest has led to numerous studies reporting mammographically occult breast cancers detected on magnetic resonance imaging (MRI) or ultrasound. In addition, digital mammography was shown to be more sensitive than film mammography in selected populations. Our goal was to prospectively compare cancer detection of digital mammography (DM), whole-breast ultrasound (WBUS), and contrast-enhanced MRI in a high-risk screening population previously screened negative by film screen mammogram (FSM).

METHODS

During a 2-year period, 609 asymptomatic high-risk women with nonactionable FSM examinations presented for a prospective multimodality screening consisting of DM, WBUS, and MRI. The FSM examinations were reinterpreted by study radiologists. Patients had benign or no suspicious findings on clinical examination. The cancer yield by modality was evaluated.

RESULTS

Twenty cancers were diagnosed in 18 patients (nine ductal carcinomas in situ and 11 invasive breast cancers). The overall cancer yield on a per-patient basis was 3.0% (18 of 609 patients). The cancer yield by modality was 1.0% for FSM (six of 597 women), 1.2% for DM (seven of 569 women), 0.53% for WBUS (three of 567 women), and 2.1% for MRI (12 of 571 women). Of the 20 cancers detected, some were only detected on one imaging modality (FSM, n = 1; DM, n = 3; WBUS, n = 1; and MRI, n = 8).

CONCLUSION

The addition of MRI to mammography in the high-risk group has the greatest potential to detect additional mammographically occult cancers. The incremental cancer yield of WBUS and DM is much less.

Evaluating the correlation between film mammography and MRI for screening women with increased breast cancer risk

RATIONALE AND OBJECTIVES

Breast magnetic resonance imaging (MRI) is increasingly being added to mammography for screening asymptomatic women at increased risk of breast cancer. Because the direction and extent of correlation between mammography and MRI could potentially result in over- or underestimation of the diagnostic gain related to using MRI as an adjunct to mammographic screening, we performed an analysis to evaluate the extent of correlation between mammography and MRI.

MATERIALS AND METHODS

We reviewed the published literature to identify multimodality breast cancer screening studies reporting the sensitivity of mammography and MRI, alone and in combination, for breast cancer diagnosis. After calculating the expected sensitivity of combined mammography and MRI under conditions of test independence (no correlation), we compared the calculated and observed sensitivities for combined mammography and MRI. We then calculated correlation coefficients for mammography and MRI.

RESULTS

Seven studies of multimodality screening in women at increased risk of developing breast cancer were included for analysis. Of these studies, the correlation between film mammography and MRI was positive in three studies, negative in two studies, and not identified in two studies. The calculated correlation coefficients ranged from -0.38 to 0.18. In six of seven studies, the 95% confidence interval for the correlation coefficient included 0.0, indicating no significant correlation.

CONCLUSIONS

Evidence from published trials of multimodality breast cancer screening identified no statistically significant correlation between film mammography and MRI. Using both tests for breast cancer screening is likely to improve the early detection of breast cancer in women at increased risk.

[Breast cancer screening imaging: what do we do]

The purpose of this review is to evaluate the value of different breast imaging technics and their place for individual and mass screening of breast cancer according to the randomized studies on digital mammography and ultrasound screening. Analogic and numerical mammograms are validated for screening of women aged from 50 and 74 years. The additional value of ultrasound is therefore proven when the increased risk is moderate. When risk is higher (genetic or familial), MRI is the method of choice associated with conventional imaging. Individual screening is recommended before 50 for women aged from 45 and 50 and for those over 74 using the same procedures as organized screening.

Diagnosis of breast cancer in women age 40 and younger: delays in diagnosis result from underuse of genetic testing and breast imaging

BACKGROUND

The impact of newer breast imaging technologies and genetic testing on the detection of breast cancer in women age 40 and younger remains unknown.

METHODS

A records review identified 628 women age 40 and younger diagnosed with breast cancer from 1996 to 2008. Patient and tumor characteristics, means of diagnosis, imaging results, and genetic testing were examined.

RESULTS

Tumors were first detected by self-examination in 71%, with a median invasive tumor size of 2.0 cm. Imaging performed at or after diagnosis visualized most tumors; mammography visualized 86%, magnetic resonance imaging (MRI) visualized 96%, and mammography plus MRI visualized more than 98% of tumors. For 81% of patients, the mammogram at diagnosis was their first mammogram. Although 50% had a family history of breast or ovarian cancer, few underwent genetic testing before their cancer diagnosis; 61 of 247 (25%) ultimately tested had a BRCA mutation.

CONCLUSIONS

Better use of genetic testing, mammography, and MRI could improve breast cancer detection in young women.

Screening and prevention of breast cancer in primary care

Mammography remains the mainstay of breast cancer screening. There is little controversy that mammography reduces the risk of dying from breast cancer by about 23% among women between the ages of 50 and 69 years, although the harms associated with false-positive results and overdiagnosis limit the net benefit of mammography. Women in their 70s may have a small benefit from screening mammography, but overdiagnosis increases in this age group as do competing causes of death. While new data support a 16% reduction in breast cancer mortality for 40- to 49-year-old women after 10 years of screening, the net benefit is less compelling in part because of the lower incidence of breast cancer in this age group and because mammography is less sensitive and specific in women younger than 50 years. Digital mammography is more sensitive than film mammography in young women with similar specificity, but no improvements in breast cancer outcomes have been demonstrated. Magnetic resonance imaging may benefit the highest risk women. Randomized trials suggest that self-breast examination does more harm than good. Primary prevention with currently approved medications will have a negligible effect on breast cancer incidence. Public health efforts aimed at increasing mammography screening rates, promoting regular exercise in all women, maintaining a healthy weight, limiting alcohol intake, and limiting postmenopausal hormone therapy may help to continue the recent trend of lower breast cancer incidence and mortality among American women.

The UK national breast cancer screening programme for survivors of Hodgkin lymphoma detects breast cancer at an early stage

Background:

Supradiaphragmatic radiotherapy (SRT) to treat Hodgkin's lymphoma (HL) at a young age increases the risk of breast cancer (BC). A national notification risk assessment and screening programme (NRASP) for women who were treated with SRT before the age of 36 years was instituted in the United Kingdom in 2003. In this study, we report the implementation and screening results from the largest English Cancer Network.

Methods:

A total of 417 eligible women were identified through cancer registry/hospital databases and from follow-up (FU) clinics. Screening results were collated retrospectively, and registry searches were used to capture BC cases.

Results:

Of the 417 women invited for clinical review, 243 (58%) attended. Of these 417 women, 23 (5.5%) have been diagnosed with BC, a standardised incidence ratio of 2.9 compared with the age-matched general population. Of five invasive BCs diagnosed within the NRASP, none involved axillary lymph nodes compared with 7 of 13 (54%) diagnosed outside the programme (P<0.10). The mean latency for BC cases was 19.5±8.35 years and the mean FU duration for those unaffected by BC was 14.6±9.11 years (P<0.01), suggesting that those unaffected by BC remain at high risk. Recall and negative biopsy rates were acceptable (10.5 and 0.8%, respectively).

Conclusions:

The NRASP appears to detect BC at an early stage with acceptable biopsy rates, although numbers are small. Determination of NRASP results on a national basis is required for the accurate evaluation of screening efficacy in women previously treated with SRT.

Temporal sampling requirements for reference region modeling of DCE-MRI data in human breast cancer

PURPOSE

To assess the temporal sampling requirements needed for quantitative analysis of dynamic contrast-enhanced MRI (DCE-MRI) data with a reference region (RR) model in human breast cancer.

MATERIALS AND METHODS

Simulations were used to study errors in pharmacokinetic parameters (K(trans) and v(e)) estimated by the RR model using six DCE-MRI acquisitions over a range of pharmacokinetic parameter values, arterial input functions, and temporal samplings. DCE-MRI data were acquired on 12 breast cancer patients and parameters were estimated using the native resolution data (16.4 seconds) and compared to downsampled 32.8-second and 65.6-second data.

RESULTS

Simulations show that, in the majority of parameter combinations, the RR model results in an error less than 20% in the extracted parameters with temporal sampling as poor as 35.6 seconds. The experimental results show a high correlation between K(trans) and v(e) estimates from data acquired at 16.4-second temporal resolution compared to the downsampled 32.8-second data: the slope of the regression line was 1.025 (95% confidence interval [CI]: 1.021, 1.029), Pearson's correlation r = 0.943 (95% CI: 0.940, 0.945) for K(trans), and 1.023 (95% CI: 1.021. 1.025), r = 0.979 (95% CI: 0.978, 0.980) for v(e). For the 64-second temporal resolution data the results were: 0.890 (95% CI: 0.894, 0.905), r = 0.8645, (95% CI: 0.858, 0.871) for K(trans), and 1.041 (95% CI: 1.039, 1.043), r = 0.970 (95% CI: 0.968, 0.971) for v(e).

CONCLUSION

RR analysis allows for a significant reduction in temporal sampling requirements and this lends itself to analyze DCE-MRI data acquired in practical situations.

Screening for breast cancer with MRI: recent experience from the Australian Capital Territory

The American Cancer Society now recommends annual MRI screening for women at 20-25% or greater lifetime risk of breast cancer. The role of MRI screening in other risk subgroups is unproved because of insufficient data. Our study comprised 209 breast MRI scans carried out in 171 asymptomatic patients (age range 22-67 years, mean 46 years), referred between January 2005 and June 2008. Targeted ultrasound was carried out in 32 episodes (15%) and biopsies were taken in 23 patients (13%). In four patients, MR-guided procedures were required to establish a diagnosis, two using hook-wire localization and two by means of vacuum-assisted biopsy. Seven cancers were detected by MRI in the 171 patients, with a yield of 4.1%. Only one of the seven cancers was also shown by x-ray mammography. Four patients had invasive ductal cancer (all axillary node negative) and three had high-grade ductal carcinoma in situ or pleomorphic lobular carcinoma in situ. The three women with in situ disease were all potentially high risk, based on the National Breast and Ovarian Cancer Centre (NBOCC) criteria. Three women with invasive breast cancer were at only average risk based on NBOCC criteria, but two of these had extremely dense breasts. A fourth patient, found to have multifocal invasive cancer, had a personal history of contralateral breast cancer, but no relevant family history. Our findings suggest that breast MRI could be used to screen a larger Australian population at increased risk of developing breast cancer.

Association of routine pretreatment magnetic resonance imaging with time to surgery, mastectomy rate, and margin status

BACKGROUND

The benefit of breast MRI for newly diagnosed breast cancer patients is uncertain. This study characterizes those receiving MRI versus those who did not, and reports on their short-term surgical outcomes, including time to operation, margin status, and mastectomy rate.

STUDY DESIGN

All patients seen in a multidisciplinary breast cancer clinic from July 2004 to December 2006 were retrospectively reviewed. Patients were evaluated by a radiologist, a pathologist, and surgical, radiation, and medical oncologists.

RESULTS

Among 577 patients, 130 had pretreatment MRIs. MRI use increased from 2004 (referent, 13%) versus 2005 (24%, p=0.014) and 2006 (27%, p=0.002). Patients having MRIs were younger (52.5 versus 59.0 years, p < 0.001), but its use was not associated with preoperative chemotherapy, family history of breast or ovarian cancer, presentation, or tumor features. MRI was associated with a 22.4-day delay in pretreatment evaluation (p=0.011). Breast conserving therapy (BCT) was attempted in 320 of 419 patients with complete surgical data. The odds ratio for mastectomy, controlling for T size and stage, was 1.80 after MRI versus no MRI (p=0.024). Patients having MRIs did not have fewer positive margins at lumpectomy (21.6% MRI versus 13.8% no MRI, p=0.20), or conversions from BCT to mastectomy (9.8% MRI versus 5.9% no MRI, p=0.35).

CONCLUSIONS

Breast MRI use was not confined to any particular patient group. MRI use was not associated with improved margin status or BCT attempts, but was associated with a treatment delay and increased mastectomy rate. Without evidence of improved oncologic outcomes as a result, our study does not support the routine use of MRI to select patients or facilitate the performance of BCT.

Prospective study of breast MRI in BRCA1 and BRCA2 mutation carriers: effect of mutation status on cancer incidence

Annual MRI screening is recommended as an adjunct to mammography for BRCA1 and BRCA2 mutation carriers. Prophylactic oophorectomy has been shown to decrease breast cancer risk in BRCA1/2 mutation carriers. Here, we aimed to examine the combined effects of MRI and oophorectomy. For this purpose, 93 BRCA1/2 mutation carriers were screened with yearly mammograms and yearly MRI scans. Study endpoints were defined as date of breast cancer diagnosis, date of prophylactic mastectomy, or date of most recent contact. Of 93 women, with a median age of 47, 80 (86%) had prophylactic oophorectomy. Fifty-one women (55%) had BRCA1 mutations. A total of 283 MRI scans were performed. Eleven breast cancers (9 invasive, 2 ductal carcinoma in situ) were detected in 93 women (12%) with a median follow-up of 3.2 years (incidence 40 per 1,000 person-years). Six cancers were first detected on MRI, three were first detected by mammogram, and two were "interval cancers." All breast cancers occurred in BRCA1 mutation carriers (incidence 67 per 1,000 person-years). Apart from BRCA1 vs. BRCA2 mutation status, there were no other significant predictors of breast cancer incidence. Most invasive breast cancers were estrogen receptor negative (7 of 9) and lymph node negative (7 of 9). There have been no systemic recurrences with a median follow-up of 19 months after cancer diagnosis. Finally, it was concluded that all breast cancers occurred in BRCA1 mutation carriers, in most cases despite oophorectomy. These data suggest that surveillance and prevention strategies may have different outcomes in BRCA1 and BRCA2 mutation carriers.

Eligibility for magnetic resonance imaging screening in the United Kingdom: effect of strict selection criteria and anonymous DNA testing on breast cancer incidence in the MARIBS Study

INTRODUCTION

A UK multicenter study compared the performance of contrast enhanced-magnetic resonance imaging with X-Ray Mammography in women at high-risk of breast cancer commencing in 1997. Selection criteria were used to identify women with at least 0.9% annual risk of breast cancer.

METHODS

Women at high breast cancer risk, with a strong family history and/or high probability of a BRCA1/BRCA2/TP53 mutation, were recruited from 22 centers. Those not known as gene carriers were asked to give a blood sample, which was tested anonymously for mutations. Women ages 35 to 49 years were offered annual screening for 2 to 7 years. Study eligibility at entry was assessed retrospectively by detailed examination of pedigrees and overall eligibility accounting for computer risk assessment and mutation results.

RESULTS

Seventy-eight of 837 (9%) women entered for screening were ineligible using the strict entry criteria. Thirty-nine cancers were detected in 1,869 women-years in study (incidence 21 per 1,000). Including 3,561 further years follow-up, 28 more breast cancers were identified (12 of 1,000). Incidence rates for 759 eligible women were 22 of 1,000 in study and 13 of 1,000 in total follow-up, compared with 9 of 1,000 and 4 of 1,000, respectively, in 78 ineligible women. Breast cancer rates were higher for BRCA2 than BRCA1 after testing anonymized samples in this selected population at 65 of 1,000 in study and 36 of 1,000 in total follow-up for BRCA2 compared with 44 of 1,000 and 27 of 1,000 for BRCA1.

CONCLUSIONS

Strict enforcement of study criteria would have minimally improved the power of the study, whereas testing for BRCA1/2 in advance would have substantially increased the detection rates.

Evolving Role of MRI in Breast Cancer Imaging

Breast MRI is a useful adjunctive tool to mammography. In the past 2 decades, contrast-enhanced breast MRI has become an integral component of breast imaging. In patients with known breast cancer, breast MRI can assess the extent of disease, including multifocal tumors and chest wall invasion. Improvements in MRI technology have resulted in improved ability for diagnosing mammographically and clinically occult breast cancer. With the use of contrast, the sensitivity of breast MRI for assessing invasive breast cancer approaches 100%, although specificity is lower. The clinical indications for the use of breast MRI will continue to evolve and expand.

Accuracy of the Fischer scoring system and the Breast Imaging Reporting and Data System in identification of malignant breast lesions

BACKGROUND AND OBJECTIVES

Fischer developed a scoring system in 1999 that made identifying malignnant lesions much easier for inexperienced radiologists. Our study was performed to assess whether this scoring system would help beginners to accurately diagnose breast lesions on magnetic resonance (MR) imaging and to assess the correlation between the magnetic resonance mammography Breast Imaging Reporting and Data System (MRM BI-RADS) grade and the final diagnosis.

PATIENTS AND METHODS

The lesion morphology and contrast kinetics of 63 masses in 41 patients were evaluated on MRI and accorded a MRM BI-RADS final assessment category using the Fischer scoring system. The accuracy was evaluated after the final diagnosis was obtained by tissue sampling and follow-up imaging.

RESULTS

There were 25 malignant and 30 benign lesions. Eight lesions were seen by MRI only and we could not verify their pathology since we did not have MR-guided biopsy facilities at the time of the study. On MR mammography, the proven carcinomatous lesions were characterized as BI-RADS category V in 16 (64%), category IV in 7 (28%), and category III in 2 (8%) lesions. Benign lesions were graded as category V in 3 (10%), category IV in 6 (20%), and category III in 3 (10%), category II in 10 (33%) and category I in 8 (27%) lesions. The MRM BI-RADS category accurately predicted malignancy in 92% and a benign pathology in 70% of the lesions. The overlap between the MRM features of chronic inflammatory lesions and carcinomas resulted in a lower accuracy in diagnosing benign as compared to malignant lesions.

CONCLUSION

The MRM BI-RADS lexicon using the Fischer scoring system is useful and has a high predictive value, especially for malignant breast lesions, and is easy to apply. Overlapping features between benign inflammatory and malignant lesions might yield a reduced accuracy in inflammatory pathologies.

Breast cancer screening: emerging role of new imaging techniques as adjuncts to mammography

Early detection of breast cancer has been shown to reduce breast cancer deaths in randomised controlled trials (RCTs) of mammography in women aged 50-69 years, with weaker evidence of benefit in those aged 40-49 or 70 years and older. Magnetic resonance imaging (MRI) and ultrasonography have been evaluated in breast cancer screening, relative to, or in addition to, mammography, in selected populations; neither test has been examined in an RCT, and thus evidence of associated screening benefit is uncertain. MRI is more sensitive than mammography in screening women with suspected or proven inherited mutations of the breast cancer genes. The addition of MRI in screening this population detects 8-24 additional cancers per 1000 screens, but also significantly increases a woman's risk of being recalled for investigation or surgical biopsy for false-positive findings. In Australia, Medicare funding for MRI screening of women in specific risk groups was announced in February 2009. Ultrasonography can detect cancers not identified on mammography in asymptomatic women with dense breast tissue. Incremental ultrasound cancer detection is reported in 0.27%-0.46% of women with mammography-negative dense breasts; evidence varies on its association with false-positive findings. Computer-aided detection (CAD) is a complementary tool to mammography, prompting the reader to consider lesions on the mammogram that may represent cancer. Emerging evidence and improved CAD technology are likely to help define its role in breast screening.

Cost effectiveness of breast cancer screening with contrast-enhanced MRI in high-risk women

PURPOSE

The aim of this study was to estimate the cost effectiveness of breast cancer screening with contrast-enhanced magnetic resonance imaging (MRI), with and without adjunctive x-ray mammography (XM), compared with XM alone in high-risk women.

MATERIALS AND METHODS

A model was developed to depict the consequences of screening with MRI and/or XM for cohorts of 10,000 women with BRCA1/2 mutations and women with other high-risk characteristics, respectively. The model predicted the number of women correctly and incorrectly diagnosed with each strategy and lifetime consequences in terms of additional care, patient utilities, life expectancy, and quality-adjusted life-years (QALYs). Cost effectiveness was calculated in terms of cost per QALY gained.

RESULTS

Among the 400 women (of 10,000) with BRCA1/2 mutations and undiagnosed breast cancer, 361 cases would be detected with MRI and XM, 290 with MRI, and 160 with XM. False-positive results would total 1,526, 1,190, and 528, respectively. Cost per QALY gained with MRI and XM compared with XM alone for women with BRCA1/2 mutations was $25,277. Among other high-risk women, cost per QALY gained with MRI and XM compared with XM alone varied depending on the prevalence of breast cancer, ranging from $45,566 (300 cases) to $310,616 (50 cases). The cost effectiveness of MRI alone compared with XM alone was similar.

CONCLUSION

Screening with MRI, alone or in combination with XM, in women with BRCA1/2 mutations is cost effective by current standards compared with XM alone. In women with other high-risk characteristics, MRI screening may also be cost effective, depending on the expected prevalence of undiagnosed breast cancer at the time of screening.