Screening Breast Ultrasound: Update After 10 Years of Breast Density Notification Laws.

OBJECTIVE. Breast density notification laws have grown from the first state legislation in Connecticut in 2009 to a federally mandated update to the Mammography Quality Standards Act in 2019. CONCLUSION. The increasing recognition of limited mammographic sensitivity in women with dense breasts has led to greater utilization of supplemental screening ultrasound. Robust data support improved detection of small node-negative invasive breast cancers with adjunctive ultrasound. Digital breast tomosynthesis and other emerging modalities may also play a role in screening guidelines.

Breast Density Legislation and Clinical Evidence.

Breast density inform legislation is widely accepted in the United States and has fueled research regarding the clinical significance of dense breast tissue present on mammography and the value of supplemental screening. This article reviews the origins and current status of breast density inform laws and strategies for optimal breast density determination. Clinical evidence that dense breast tissue is associated with increased breast cancer risk is presented, together with a review of relative risk compared with other risk factors. Finally, there is in-depth analysis regarding the rationale, benefits, and risks of supplemental screening modalities, including ultrasound, tomosynthesis, and MRI.

Implementation of Whole-Breast Screening Ultrasonography.

Whole-breast screening ultrasonography is being increasingly implemented in breast imaging centers because numerous studies have shown the benefit of supplemental screening for women with dense breasts and breast density notification laws are becoming more widespread. This article reviews the numerous considerations involved in integrating a screening ultrasonography program into a busy practice.

Knowledge of Density and Screening Ultrasound.

To determine breast density awareness and attitudes regarding supplemental breast ultrasound screening since implementation of the nation's first breast density notification law, Connecticut Public Act 09-41. A self-administered survey was distributed at a Connecticut academic breast imaging center between February 2013 and February 2014. Women with prior mammography reports describing heterogeneous or extremely dense breast tissue were invited to participate when presenting for screening mammography, screening ultrasound, or both. Data were collected on breast density awareness, history of prior ultrasounds, attitudes toward ultrasound and breast-cancer risk, and demographics. Data were collected from 950 completed surveys. The majority of surveyed women (92%) were aware of their breast density, and 77% had undergone a prior screening ultrasound. Forty-three percent of participants who were aware of their breast density also expressed increased anxiety about developing breast cancer due to having dense breast tissue. Caucasian race and higher education were significantly associated (p < 0.05) with knowledge of personal breast density (93% and 95%, respectively) and having a prior screening breast ultrasound (79% and 80%, respectively). Patients with less than a college degree (82%) were significantly more likely to rely exclusively on their provider's recommendation regarding obtaining screening ultrasound (p < 0.05). Breast density awareness is strongly associated with higher education, higher income, and Caucasian race. Non-Caucasian patients and those with less than a college education rely more heavily on their physicians' recommendations regarding screening ultrasound. Among women aware of their increased breast density, nearly half reported associated increased anxiety regarding the possibility of developing breast cancer.

Advances in Digital Breast Tomosynthesis.

OBJECTIVE: Digital breast tomosynthesis (DBT) has rapidly emerged as an important new imaging tool that reduces the masking effect of overlapping fibroglandular tissue, thereby improving breast cancer detection. This article will review key features of DBT including technique, clinical implementation, and benign and malignant imaging findings. We will also present the benefits of DBT in screening, diagnostic workup, and image-guided biopsy. CONCLUSION: Tomosynthesis improves interpretive performance and will likely replace conventional 2D mammography in clinical practice.

Core Breast Biopsies Showing Lobular Carcinoma In Situ Should Be Excised and Surveillance Is Reasonable for Atypical Lobular Hyperplasia.

OBJECTIVE: The purpose of this article is to determine the upgrade rate to ductal carcinoma in situ (DCIS) or invasive carcinoma at excision at the same site after percutaneous breast biopsy findings of atypical lobular hyperplasia (ALH) or lobular carcinoma in situ (LCIS) using current imaging and strict pathologic criteria. MATERIALS AND METHODS: From January 2006 through September 2013, 32,960 breast core biopsies were performed; 1084 (3.3%) core biopsies found ALH or classic LCIS. For 447 lesions in 433 women, this was the only high-risk lesion at that site, with no ipsilateral malignancy, and results of excision were available. RESULTS: Among the 447 lesions, 22 (4.9%) were malignant at excision, including 10 invasive carcinomas (two grade 2 and eight grade 1; all node negative) and 12 DCIS. The upgrade rate of LCIS was 9.3% (10/108; 95% CI, 5.1-16.2%) and that of ALH was 3.5% (12/339; 95% CI, 2.0-6.1%; p = 0.02). After excluding five cases with radiologic-pathologic discordance and reclassifying one core from ALH to LCIS at review, the upgrade rate for LCIS remained higher (8.4%; 9/107; 95% CI, 4.5-15.2%) than that for ALH (2.4%; 8/335; 95% CI, 1.2-4.6%; p = 0.01). CONCLUSION: Excision is recommended for LCIS on core biopsy because of its 8.4-9.3% upgrade rate. Excluding discordant cases, patients with other high-risk lesions or concurrent malignancy, the risk of upgrade of ALH was 2.4%. Surveillance at 6, 12, and 24 months can be performed in lieu of excision because a short delay in diagnosis of the few malignancies is not expected to cause harm.

Breast cancer biology varies by method of detection and may contribute to overdiagnosis.

BACKGROUND: Recently, it has been suggested that screening mammography may result in some degree of overdiagnosis (ie, detection of breast cancers that would never become clinically important within the lifespan of the patient). The extent and biology of these overdiagnosed cancers, however, is not well understood, and the effect of newer screening modalities on overdiagnosis is unknown. METHODS: We performed a retrospective review of a prospectively collected database of breast cancers diagnosed at the Yale Breast Center from 2004-2014. The mode of initial presentation was categorized into 5 groups: screening mammogram, screening magnetic resonance imaging, screening ultrasonography, self-detected masses, and physician-detected masses. RESULTS: Compared with cancers presenting with masses, cancers detected by image-based screening were more likely to present with ductal carcinoma-in-situ or T1 cancers (P < .001). In addition to a simple stage shift, however, cancers detected by image-based screening were also more likely to be luminal and low-grade cancers; symptomatic cancers were more likely high-grade and triple-negative (P < .001, respectively). On a multivariate analysis, adjusting for age, race, and tumor size, cancers detected by mammogram, US, and magnetic resonance imaging had greater odds of being luminal (odds ratio 1.8, 95% confidence interval, 1.5-2.3; odds ratio 2.2, 95% confidence interval, 1.1-4.7; and odds ratio 4.7, 95% confidence interval, 2.1-10.6, respectively), and low-grade (odds ratio 2.2, 95% confidence interval, 1.6-2.9; odds ratio 4.9, 95% confidence interval, 2.7-8.9; and odds ratio 4.6, 95% confidence interval, 2.6-8.1, respectively) compared with cancers presenting with self-detected masses. CONCLUSION: Screening detects cancers with more indolent biology, potentially contributing to the observed rate of overdiagnosis. With magnetic resonance imaging and US being used more commonly for screening, the rate of overdiagnosis may increase further.

Tomosynthesis in the Diagnostic Setting: Changing Rates of BI-RADS Final Assessment over Time.

Purpose To evaluate the effect of tomosynthesis in diagnostic mammography on the Breast Imaging Reporting and Data System (BI-RADS) final assessment categories over time. Materials and Methods This retrospective study was approved by the institutional review board. The authors reviewed all diagnostic mammograms obtained during a 12-month interval before (two-dimensional [2D] mammography [June 2, 2010, to June 1, 2011]) and for 3 consecutive years after (tomosynthesis year 1 [2012], tomosynthesis year 2 [2013], and tomosynthesis year 3 [2014]) the implementation of tomosynthesis. The requirement to obtain informed consent was waived. The rates of BI-RADS final assessment categories 1-5 were compared between the 2D and tomosynthesis groups. The positive predictive values after biopsy (PPV3) for BI-RADS category 4 and 5 cases were compared. The mammographic features (masses, architectural distortions, calcifications, focal asymmetries) of lesions categorized as probably benign (BI-RADS category 3) and those for which biopsy was recommended (BI-RADS category 4 or 5) were reviewed. The χ(2) test was used to compare the rates of BI-RADS final assessment categories 1-5 between the two groups, and multivariate logistic regression analysis was performed to compare all diagnostic studies categorized as BI-RADS 3-5. Results There was an increase in the percentage of cases reported as negative or benign (BI-RADS category 1 or 2) with tomosynthesis (58.7% with 2D mammography vs 75.8% with tomosynthesis at year 3, P < .0001). A reduction in the percentage of probably benign (BI-RADS category 3) final assessments also occurred (33.3% with 2D mammography vs 16.4% with tomosynthesis at year 3, P < .0001). Although the rates of BI-RADS 4 or 5 assessments did not change significantly with tomosynthesis (8.0% with 2D mammography vs 7.8% with tomosynthesis at year 3, P = .2), there was a significant increase in the PPV3 (29.6% vs 50%, respectively; P < .0001). These trends increased during the 3 years of tomosynthesis use. Conclusion Tomosynthesis in the diagnostic setting resulted in progressive shifts in the BI-RADS final assessment categories over time, with a significant increase in the proportion of studies classified as normal, a continued decrease in the rate of studies categorized as probably benign, and improved diagnostic confidence in biopsy recommendations. (©) RSNA, 2016.

Tomosynthesis-detected Architectural Distortion: Management Algorithm with Radiologic-Pathologic Correlation.

As use of digital breast tomosynthesis becomes increasingly widespread, new management challenges are inevitable because tomosynthesis may reveal suspicious lesions not visible at conventional two-dimensional (2D) full-field digital mammography. Architectural distortion is a mammographic finding associated with a high positive predictive value for malignancy. It is detected more frequently at tomosynthesis than at 2D digital mammography and may even be occult at conventional 2D imaging. Few studies have focused on tomosynthesis-detected architectural distortions to date, and optimal management of these distortions has yet to be well defined. Since implementing tomosynthesis at our institution in 2011, we have learned some practical ways to assess architectural distortion. Because distortions may be subtle, tomosynthesis localization tools plus improved visualization of adjacent landmarks are crucial elements in guiding mammographic identification of elusive distortions. These same tools can guide more focused ultrasonography (US) of the breast, which facilitates detection and permits US-guided tissue sampling. Some distortions may be sonographically occult, in which case magnetic resonance imaging may be a reasonable option, both to increase diagnostic confidence and to provide a means for image-guided biopsy. As an alternative, tomosynthesis-guided biopsy, conventional stereotactic biopsy (when possible), or tomosynthesis-guided needle localization may be used to achieve tissue diagnosis. Practical uses for tomosynthesis in evaluation of architectural distortion are highlighted, potential complications are identified, and a working algorithm for management of tomosynthesis-detected architectural distortion is proposed.

Early clinical experience with digital breast tomosynthesis for screening mammography.

PURPOSE: To examine recall rates from screening mammography and the mammographic findings that caused recall in women who underwent digital breast tomosynthesis with conventional mammography (referred to as two-dimensional [ 2D two-dimensional ] with three-dimensional [ 3D three-dimensional ] imaging [ 2D two-dimensional + 3D three-dimensional ]) and in women who underwent conventional mammography alone (referred to as 2D two-dimensional ). MATERIALS AND METHODS: This was an institutional review board-approved, HIPAA-compliant study with waivers of informed consent. A retrospective review of 2D two-dimensional + 3D three-dimensional and 2D two-dimensional screening mammograms from August 1, 2011, to December 31, 2012, was performed. Recall rates and abnormalities that caused recall were compared by controlling for differences in patient age, breast density, and risk factors. Cancer detection rate was assessed from this time period and from 1 year before the introduction of tomosynthesis for a historic control. RESULTS: This study included 17 955 screening mammograms; of the total, there were 8591 (47.8%) 2D two-dimensional + 3D three-dimensional screening examinations and 9364 (52.2%) 2D two-dimensional examinations. The recall rate was 7.8% (671 of 8592) for 2D two-dimensional + 3D three-dimensional and 12.3% (1154 of 9364) for 2D two-dimensional (P < .0001); the rate of recall was 36.6% lower in the 2D two-dimensional + 3D three-dimensional group than in the 2D two-dimensional group. Recall rates for the 2D two-dimensional + 3D three-dimensional group were significantly lower for patients with asymmetries, ( 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 3.1% [267 of 8591] vs 7.4% [689 of 9364], respectively; P < .0001) and calcifications ( 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 2.4% [205 of 8591] vs 3.2% [297 of 9364], respectively; P = .0014). For patients with masses and architectural distortion, the difference in recall rates was not significant (masses: 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 2.5% [215 of 8591] vs 2.5% [237 of 9364], respectively; P = .90; architectural distortion: 2D two-dimensional + 3D three-dimensional vs 2D two-dimensional , 0.68% [58 of 8591] vs 0.69% [65 of 9364]; P = .88). Cancer detection was highest in the 2D two-dimensional + 3D three-dimensional group at 5.9 cancers per 1000 examinations, with 5.7 cancers per 1000 examinations in the concurrent 2D two-dimensional group, and 4.4 cancers per 1000 examinations in the historic control. CONCLUSION: Use of tomosynthesis ( 2D two-dimensional + 3D three-dimensional ) compared with conventional mammography ( 2D two-dimensional ) is associated with a lower recall rate of screening mammography, most often for asymmetries.

3.0 Tesla vs 1.5 Tesla breast magnetic resonance imaging in newly diagnosed breast cancer patients.

AIM: To compare 3.0 Tesla (T) vs 1.5T magnetic resonance (MR) imaging systems in newly diagnosed breast cancer patients. METHODS: Upon Institutional Review Board approval, a Health Insurance Portability and Accountability Act-compliant retrospective review of 147 consecutive 3.0T MR examinations and 98 consecutive 1.5T MR examinations in patients with newly diagnosed breast cancer between 7/2009 and 5/2010 was performed. Eleven patients who underwent neoadjuvant chemotherapy in the 3.0T group were excluded. Mammographically occult suspicious lesions (BIRADS Code 4 and 5) additional to the index cancer in the ipsilateral and contralateral breast were identified. Lesion characteristics and pathologic diagnoses were recorded, and results achieved with both systems compared. Statistical significance was analyzed using Fisher's exact test. RESULTS: In the 3.0T group, 206 suspicious lesions were identified in 55% (75/136) of patients and 96% (198/206) of these lesions were biopsied. In the 1.5T group, 98 suspicious lesions were identified in 53% (52/98) of patients and 90% (88/98) of these lesions were biopsied. Biopsy results yielded additional malignancies in 24% of patients in the 3.0T group vs 14% of patients in the 1.5T group (33/136 vs 14/98, P = 0.07). Average size and histology of the additional cancers was comparable. Of patients who had a suspicious MR imaging study, additional cancers were found in 44% of patients in the 3.0T group vs 27% in the 1.5T group (33/75 vs 14/52, P = 0.06), yielding a higher positive predictive value (PPV) for biopsies performed with the 3.0T system. CONCLUSION: 3.0T MR imaging detected more additional malignancies in patients with newly diagnosed breast cancer and yielded a higher PPV for biopsies performed with the 3.0T system.

Breast ultrasonography: state of the art.

Ultrasonography (US) is an indispensable tool in breast imaging and is complementary to both mammography and magnetic resonance (MR) imaging of the breast. Advances in US technology allow confident characterization of not only benign cysts but also benign and malignant solid masses. Knowledge and understanding of current and emerging US technology, along with the application of meticulous scanning technique, is imperative for image optimization and diagnosis. The ability to synthesize breast US findings with multiple imaging modalities and clinical information is also necessary to ensure the best patient care. US is routinely used to guide breast biopsies and is also emerging as a supplemental screening tool in women with dense breasts and a negative mammogram. This review provides a summary of current state-of-the-art US technology, including elastography, and applications of US in clinical practice as an adjuvant technique to mammography, MR imaging, and the clinical breast examination. The use of breast US for screening, preoperative staging for breast cancer, and breast intervention will also be discussed.

Screening US in patients with mammographically dense breasts: initial experience with Connecticut Public Act 09-41.

PURPOSE: To determine performance and utilization of screening breast ultrasonography (US) in women with dense breast tissue who underwent additional screening breast US in the 1st year since implementation of Connecticut Public Act 09-41 requiring radiologists to inform patients with heterogeneous or extremely dense breasts at mammography that they may benefit from such examination. MATERIALS AND METHODS: Informed consent was waived for this institutional review board-approved, HIPAA-compliant retrospective review of 935 women with dense breasts at mammography who subsequently underwent handheld screening and whole-breast US from October 1, 2009, through September 30, 2010. RESULTS: Of 935 women, 614 (65.7%) were at low risk, 149 (15.9%) were at intermediate risk, and 87 (9.3%) were at high risk for breast cancer. Of the screening breast US examinations, in 701 (75.0%), results were classified as Breast Imaging Reporting and Data System (BI-RADS) category 1 or 2; in 187 (20.0%), results were classified as BI-RADS category 3; and in 47 (5.0%), results were classified as BI-RADS category 4. Of 63 aspirations or biopsies recommended and performed in 53 patients, in nine, lesions were BI-RADS category 3, and in 54, lesions were BI-RADS category 4. Among 63 biopsies and aspirations, three lesions were malignant (all BI-RADS category 4, diagnosed with biopsy). All three cancers were smaller than 1 cm, were found in postmenopausal patients, and were solid masses. One cancer was found in each risk group. In 44 of 935 (4.7%) patients, examination results were false-positive. Overall positive predictive value (PPV) for biopsy or aspirations performed in patients with BI-RADS category 4 masses was 6.5% (three of 46; 95% confidence interval [CI]: 1.7%, 19%). Overall cancer detection rate was 3.2 cancers per 1000 women screened (three of 935; 95% CI: 0.8 cancers per 1000 women screened, 10 cancers per 1000 women screened). CONCLUSION: Technologist-performed handheld screening breast US offered to women in the general population with dense breasts can aid detection of small mammographically occult breast cancers (cancer detection rate, 0.8-10 cancers per 1000 women screened), although the overall PPV is low.

Shear-wave elastography improves the specificity of breast US: the BE1 multinational study of 939 masses.

PURPOSE: To determine whether adding shear-wave (SW) elastographic features could improve accuracy of ultrasonographic (US) assessment of breast masses. MATERIALS AND METHODS: From September 2008 to September 2010, 958 women consented to repeat standard breast US supplemented by quantitative SW elastographic examination in this prospective multicenter institutional review board-approved, HIPAA-compliant protocol. B-mode Breast Imaging Reporting and Data System (BI-RADS) features and assessments were recorded. SW elastographic evaluation (mean, maximum, and minimum elasticity of stiffest portion of mass and surrounding tissue; lesion-to-fat elasticity ratio; ratio of SW elastographic-to-B-mode lesion diameter or area; SW elastographic lesion shape and homogeneity) was performed. Qualitative color SW elastographic stiffness was assessed independently. Nine hundred thirty-nine masses were analyzable; 102 BI-RADS category 2 masses were assumed to be benign; reference standard was available for 837 category 3 or higher lesions. Considering BI-RADS category 4a or higher as test positive for malignancy, effect of SW elastographic features on area under the receiver operating characteristic curve (AUC), sensitivity, and specificity after reclassifying category 3 and 4a masses was determined. RESULTS: Median participant age was 50 years; 289 of 939 (30.8%) masses were malignant (median mass size, 12 mm). B-mode BI-RADS AUC was 0.950; eight of 303 (2.6%) BI-RADS category 3 masses, 18 of 193 (9.3%) category 4a lesions, 41 of 97 (42%) category 4b lesions, 42 of 57 (74%) category 4c lesions, and 180 of 187 (96.3%) category 5 lesions were malignant. By using visual color stiffness to selectively upgrade category 3 and lack of stiffness to downgrade category 4a masses, specificity improved from 61.1% (397 of 650) to 78.5% (510 of 650) (P<.001); AUC increased to 0.962 (P=.005). Oval shape on SW elastographic images and quantitative maximum elasticity of 80 kPa (5.2 m/sec) or less improved specificity (69.4% [451 of 650] and 77.4% [503 of 650], P<.001 for both), without significant improvement in sensitivity or AUC. CONCLUSION: Adding SW elastographic features to BI-RADS feature analysis improved specificity of breast US mass assessment without loss of sensitivity.

Breast cancer screening and problem solving using mammography, ultrasound, and magnetic resonance imaging.

Although mammography is the mainstay of early breast cancer detection, it has known limitations, particularly in women with dense breasts. As a result, additional imaging modalities, including ultrasound and contrast-enhanced magnetic resonance imaging, are also being used to supplement mammography in the early detection of occult breast cancer. This article reviews the indications and efficacy of mammography, ultrasound, and magnetic resonance imaging as both screening and diagnostic tools.

In vivo MR spectroscopic imaging of polyunsaturated fatty acids (PUFA) in healthy and cancerous breast tissues by selective multiple-quantum coherence transfer (Sel-MQC): a preliminary study.

The spatial distribution of polyunsaturated fatty acids (PUFA) in healthy and cancerous human breast tissues was measured in vivo with a selective multiple-quantum coherence transfer (Sel-MQC) technique. This method selectively detected the olefinic methylene protons (-CH = CH-) of PUFA at 5.3 ppm that were coupled with allylic methylene protons (-CH(2)-CH(2)-CH=) of unsaturated acyl chain at 2.8 ppm. Unwanted lipid coherences and tissue water signal were dephased in a single scan. Breast PUFA were mapped at 1 cm(3) voxel resolution in sagittal slices of nine breasts in six healthy female volunteers that were compared to invasive ductal carcinoma (IDC) in one breast cancer patient. The healthy breast tissue displayed continuous PUFA distribution. In some individuals, PUFA appeared throughout the breast tissue; in others they were only located in the central breast area. Decreased PUFA levels were detected in the IDC of the breast cancer patient. The magnetic resonance spectroscopic imaging (MRSI) measurement was consistent with the histological findings, ultrasound, and mammography images. PUFA patterns are sensitive to abnormal breast tissue changes including malignant transformations, and thus may serve as a biomarker for early diagnosis and therapeutic monitoring of breast disease.