Triple-negative breast cancer: correlation between imaging and pathological findings

The impact of distinct triple-negative breast cancer subtypes on misdiagnosis and diagnostic delay

BACKGROUND

Triple-negative breast cancer (TNBC) includes mostly aggressive types of breast cancer with poor prognosis. Due to its growth pattern, misinterpretation in clinical imaging is more frequent than in non-TNBC. As the group of TNBC contains heterogeneous types of tumors, marker expression-based subtypes have recently been established. We analyzed clinical features and false-negative imaging findings that could potentially lead to diagnostic delay within the subtypes.

METHODS

An exploratory analysis compared the imaging features across the a priori defined subtypes and related these findings to molecular subtype, disease stage, potential diagnostic delay, and patient outcome.

RESULTS

TNBC cases were categorized into basal-like (BL; 38.6%), mesenchymal-like (ML; 19.9%), luminal androgen receptor (LAR; 28.3%), and immunomodulatory (IM; 13.3%) subtype. In almost every third patient, malignant classification was missed in at least one imaging method. Misclassification in mammogram was more frequent in ML, while benign ultrasound features were reported more often in the BL subtype. Diagnostic delay due to misclassification in imaging led to tumor growth and/or upgrading of the tumor stage in 8.9% of BL tumors, which had the lowest overall survivals. Despite misclassification rate was higher in the ML subtype it showed better outcomes. Misdiagnosis of axillary lymph node metastasis was higher in LAR; however, this subtype showed a higher percentage of affected axillary lymph nodes.

CONCLUSION

TNBC subtypes have different clinical features, benign appearances, and diagnostic delay, which can lead to tumor stage upgrade. Future clinical studies on TNBC outcomes might consider the confounder of clinical delay in the subtypes.

Imaging features of triple-negative breast cancers according to androgen receptor status

OBJECTIVE

Different molecular subtypes of triple-negative breast cancer (TNBC) have previously been identified through analysis of gene expression profiles. The luminal androgen receptor (LAR) subtype has been shown to have a lower rate of pathologic complete response to neoadjuvant chemotherapy than other TNBC subtypes. The purpose of this study was to determine if the imaging features of TNBCs differ by AR (androgen receptor) status, which is a surrogate immunohistochemical (IHC) marker for the chemoresistant LAR subtype of TNBC.

MATERIALS AND METHODS

This sub-study was part of a clinical trial in patients with stage I-III TNBC who were prospectively monitored for response while receiving neoadjuvant systemic therapy (NAST) at a single comprehensive cancer center. This interim imaging analysis included 144 patients with known AR status measured by IHC. AR-positive (AR+) tumors were defined as those in which at least 10% of tumor cells had positive nuclear AR staining. Two experienced, fellowship-trained breast radiologists who were blinded to the IHC results retrospectively reviewed and reached consensus on all imaging studies for the index lesion (i.e., mammogram, ultrasound, and breast magnetic resonance imaging). The index lesion for each patient was reviewed and described according to the fifth edition of the Breast Imaging Reporting and Data System lexicon. Logistic regression modeling was used to identify imaging features predictive of AR status. p ≤ 0.05 was considered statistically significant.

RESULTS

Univariate logistic regression models for AR status showed that AR+ TNBC was significantly associated with heterogeneously dense breast composition on mammography (p = 0.02), mass with calcifications (p = 0.05), irregular mass shape on mammography (p = 0.03), and irregular mass shape on sonography (p = 0.003). Multivariate logistic regression models for AR status showed that AR+ TNBC was significantly associated with heterogeneously dense breast composition on mammography (p = 0.01), high mass density on mammography (p = 0.003), and irregular mass shape on sonography (p = 0.0004).

CONCLUSION

The imaging features of TNBCs differ by AR status. Multimodality breast imaging may help identify the LAR subtype of TNBC, which has been shown to be a subtype that is relatively resistant to neoadjuvant chemotherapy.

Association between digital breast tomosynthesis and molecular subtypes of breast cancer

In recent years, with increasing prevalence, particularly in young patients, breast cancer is considered to be one of the most common malignancies. The aim of the present study was to evaluate the clinical value of digital breast tomosynthesis (DBT) in diagnosing molecular subtypes of breast cancer. The present study retrospectively analyzed 134 cases of breast cancer with data regarding surgery, complete pathology and immunohistochemistry, which were collected at The Second Clinical College of Fujian Medical University (Quanzhou, China) between May 2013 and October 2014. The patients were divided into the four following molecular subtypes: Luminal A, luminal B, triple-negative and human epidermal growth factor receptor 2 (HER-2) overexpression, according to the expression of estrogen receptor, progesterone hormone receptor, HER-2 and Ki67. The association between clinical characteristics of each molecular subtype and characteristics of DBT were assessed. Calcification scores and lymph node size were the indicators that exhibited a significant difference following comparison between the four molecular subtypes. The subgroup analysis based on tumor size, calcification scores and lymph node size identified a significant difference in the distribution between patients with breast cancer with lymph node size of ≥1.5 and <1.5 cm. The analysis also revealed that the molecular subtypes of breast cancer were significantly associated with variables of calcification scores and lymph node size. In conclusion, the diagnostic imaging features, including calcification score and lymph node size, determined using DBT could be used as assistant diagnostic markers of breast cancer molecular subtypes.

Accuracy of Ultrasound for Preoperative Assessment of Tumor Size in Patients With Newly Diagnosed Breast Cancer: Is It Affected by the Background Parenchymal Echotexture?

OBJECTIVES

To assess the impact of the background parenchymal echotexture on the accuracy of tumor size estimation using breast ultrasound (US).

METHODS

A total of 140 women with newly diagnosed invasive breast cancer from January 2014 to December 2015 were enrolled in this study. Two radiologists retrospectively reviewed US images in consensus for background parenchymal echotexture interpretation. The maximum tumor diameter from static images was recorded. Tumor size measurements were considered as having agreement with histologic results if they were within ±5 mm compared to the pathologic size. The relationship between the accuracy of tumor size measurement by the background parenchymal echotexture and clinicopathologic characteristics was evaluated.

RESULTS

Of these 140 patients, 77 (55.0%) showed a homogeneous background parenchymal echotexture, whereas 63 (45.0%) showed a heterogeneous echotexture. The mean tumor size was 1.9 cm (range, 0.5-4.9 cm). The overall accuracy of tumor size measurement was 76.4% (104 of 140). Tumors of women with a homogeneous background parenchymal echotexture were more accurately measured than those of women with a heterogeneous echotexture (87.0% versus 63.5%; P = .001). Tumors with a small size (<2 cm; P = .018) and ductal carcinoma in situ-negative (P = .031), human epidermal growth factor receptor 2 (HER2)-negative (P = .053), and triple-negative (P = .016) types were also more accurately measured. The independent factors associated with inaccurate tumor size measurement were a heterogeneous background parenchymal echotexture, a large tumor size, and the HER2-enriched type (P < .05).

CONCLUSIONS

The background parenchymal echotexture affected the accuracy of tumor size estimation using breast US. Invasive breast cancers with large (≥2 cm) tumors and the HER2-enriched type showed significantly lower breast US accuracy compared to others.

Radiomics of US texture features in differential diagnosis between triple-negative breast cancer and fibroadenoma

Triple-negative breast cancer (TNBC) is sometimes mistaken for fibroadenoma due to its tendency to show benign morphology on breast ultrasound (US) albeit its aggressive nature. This study aims to develop a radiomics score based on US texture analysis for differential diagnosis between TNBC and fibroadenoma, and to evaluate its diagnostic performance compared with pathologic results. We retrospectively included 715 pathology-proven fibroadenomas and 186 pathology-proven TNBCs which were examined by three different US machines. We developed the radiomics score by using penalized logistic regression with a least absolute shrinkage and selection operator (LASSO) analysis from 730 extracted features consisting of 14 intensity-based features, 132 textural features and 584 wavelet-based features. The constructed radiomics score showed significant difference between fibroadenoma and TNBC for all three US machines (p < 0.001). Although the radiomics score showed dependency on the type of US machine, we developed more elaborate radiomics score for a subgroup in which US examinations were performed with iU22. This subsequent radiomics score also showed good diagnostic performance, even for BI-RADS category 3 or 4a lesions (AUC 0.782) which were presumed as probably benign or low suspicious of malignancy by radiologists. It was expected to assist radiologist’s diagnosis and reduce the number of invasive biopsies, although US standardization should be overcome before clinical application.

Comparison of Ultrasound Elastography and Color Doppler Ultrasonography for Distinguishing Small Triple-Negative Breast Cancer From Fibroadenoma

OBJECTIVES

To compare the performance of ultrasound elastography and color Doppler ultrasonography (US) in distinguishing small, oval, or round triple-negative breast cancer from fibroadenoma and the influence on the further management decision at US.

METHODS

In total, 131 biopsy-proven oval or round fibroadenomas (n = 68) and triple-negative breast cancers (n = 63) smaller than 2 cm were included. Three blinded readers assessed the images from US, elastography, and color Doppler imaging according to the Breast Imaging Reporting and Data System lexicon independently. Interobserver agreement was assessed, and sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve values for each data set were compared. Pathologic results were reference standards.

RESULTS

The interobserver agreements were excellent (intraclass correlation coefficients, 0.856 for US, 0.948 for elastography, and 0.864 for color Doppler). The specificity and accuracy of US with elastography were increased compared with US alone or US with Doppler imaging without statistically significant differences in sensitivity. The average area under the curve for US with elastography (0.869) was increased compared with US alone (0.650) or US with color Doppler (0.576).

CONCLUSIONS

Elastography is more useful than color Doppler imaging for distinguishing small, oval, or round triple-negative breast cancer from fibroadenoma, and elastography can help avoid biopsy of benign masses.

Optoacoustic Breast Imaging: Imaging-Pathology Correlation of Optoacoustic Features in Benign and Malignant Breast Masses

OBJECTIVE

Optoacoustic ultrasound breast imaging is a fused anatomic and functional modality that shows morphologic features, as well as hemoglobin amount and relative oxygenation within and around breast masses. The purpose of this study is to investigate the positive predictive value (PPV) of optoacoustic ultrasound features in benign and malignant masses.

SUBJECTS AND METHODS

In this study, 92 masses assessed as BI-RADS category 3, 4, or 5 in 94 subjects were imaged with optoacoustic ultrasound. Each mass was scored by seven blinded independent readers according to three internal features in the tumor interior and two external features in its boundary zone and periphery. Mean and median optoacoustic ultrasound scores were compared with histologic findings for biopsied masses and nonbiopsied BI-RADS category 3 masses, which were considered benign if they were stable at 12-month follow-up. Statistical significance was analyzed using a two-sided Wilcoxon rank sum test with a 0.05 significance level.

RESULTS

Mean and median optoacoustic ultrasound scores for all individual internal and external features, as well as summed scores, were higher for malignant masses than for benign masses (p < 0.0001). High external scores, indicating increased hemoglobin and deoxygenation and abnormal vessel morphologic features in the tumor boundary zone and periphery, better distinguished benign from malignant masses than did high internal scores reflecting increased hemoglobin and deoxygenation within the tumor interior.

CONCLUSION

High optoacoustic ultrasound scores, particularly those based on external features in the boundary zone and periphery of breast masses, have high PPVs for malignancy and, conversely, low optoacoustic ultrasound scores have low PPV for malignancy. The functional component of optoacoustic ultrasound may help to overcome some of the limitations of morphologic overlap in the distinction of benign and malignant masses.

Intrinsic Subtypes of Breast Cancers Initially Assessed as Probably Benign or of Low Suspicion on Ultrasonography Differ According to Tumor Size

OBJECTIVES

To investigate whether the intrinsic subtypes of breast cancers initially assessed as American College of Radiology Breast Imaging and Reporting System (BI-RADS) category 3 or 4a differ according to tumor size.

METHODS

A total of 444 breast cancers in 439 patients initially assessed as BI-RADS 3 or 4a through ultrasound-guided core needle biopsy were included. Tumors were classified by the size criterion of 10 mm or smaller or larger than 10 mm and categorized as the luminal type (estrogen receptor [ER] positive and/or progesterone receptor [PR] positive and human epidermal growth factor receptor 2 [HER2] negative), HER2 type (HER2 positive regardless of ER or PR status), or triple-negative type (ER negative, PR negative, and HER2 negative). The relationships between tumor size and breast cancer intrinsic subtypes were analyzed.

RESULTS

A total of 247 (55.6%) cancers were 10 mm or smaller, and 197 (44.4%) were larger than 10 mm. The luminal type was more frequently present in tumors of 10 mm or smaller (185 of 247 [74.9%]) than those larger than 10 mm (112 of 197 [56.9%]; P < .001). No significant difference was noted in the frequency of the HER2 type in tumors of 10 and mm smaller and those larger than 10 mm (27 of 247 [10.9%] versus 36 of 197 [18.3%]; P = .084). The triple-negative type was more frequently present in tumors larger than 10 mm than those of 10 mm or smaller (49 of /197 [24.9%] versus 35 of 247 [14.2%]; P = .012).

CONCLUSIONS

Breast cancers assessed as BI-RADS category 3 or 4a had differing intrinsic subtypes according to tumor size, as the luminal type was more frequently present in tumors of 10 mm or smaller than those larger than 10 mm, whereas the triple-negative type was more frequently present in tumors larger than 10 mm.

Histopathology findings of non-mass cancers on breast ultrasound

Background

There is little research done on non-mass cancers (NMCs) on breast ultrasound (US).

Purpose

To evaluate large-sectional histopathology findings of NMCs on breast US.

Material and Methods

The mammographic and histopathology features of biopsy proven 36 breast cancers which showed pure non-mass lesions on US were retrospectively reviewed.

Results

The most common mammographic finding was microcalcification (23/35, 65.7%); fine pleomorphic microcalcification was predominant (18/23, 78.3%). The main tumor type was pure ductal carcinoma in situ (DCIS) (14/36, 38.9%) and DCIS with micro- or minimal invasion (11/36, 30.6%). Among the 25 DCIS, histologic grade was high in 15 (60.0%) and intermediate in nine (36%); comedo necrosis was seen in 17 (68%). Immunohistochemical analysis was available in 27 lesions and showed HER2-overexpression in 12 (44.4%) and triple-negative in two (7.4%).

Conclusion

According to our limited patient sample, NMCs on breast US were mainly associated with high-grade DCIS.

Clinicopathological and Ultrasonic Features of Triple-Negative Breast Cancers: A Comparison with Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor-2-Negative Breast Cancers

The purpose of this study was to analyze the clinicopathological and ultrasound characteristics of triple-negative breast cancers (TNBCs) and compare these findings with those for hormone receptor-positive (HR-positive)/human epidermal growth factor receptor-2-negative (HER-2-negative) tumors. Seventy-five TNBCs and 135 HR-positive/HER-2-negative breast cancers were reviewed. Data from conventional ultrasound, Doppler vascularity and elastography were included in the analysis. TNBCs had a higher histologic grade and Ki-67 level. On ultrasound, TNBCs often appeared as microlobulated, markedly hypo-echoic masses with an abrupt interface boundary, posterior acoustic enhancement, absence of calcifications and more characteristics of surrounding tissue. Results from multivariate regression analysis revealed that margin, posterior acoustic features and surrounding tissue features of tumors were independent predictive factors in differentiating TNBCs from HR-positive/HER-2-negative tumors. Our results suggest that a thorough evaluation of sonographic findings might be useful in discriminating between TNBCs and HR-positive/HER-2-negative tumors, which may provide accurate evidence for clinical early diagnosis.

Three-dimensional versus two-dimensional shear-wave elastography: Associations of mean elasticity values with prognostic factors and tumor subtypes of breast cancer

PURPOSE

To explore associations between prognostic factors and subtypes of invasive breast cancer (IBC) and elasticity values using three-dimensional (3D) and two-dimensional (2D) shear-wave elastography (SWE).

MATERIALS AND METHODS

Mean elasticity values (kPa) of 121 IBCs were measured using both 3D and 2D SWE. Associations between these values and prognostic factors and subtypes were analyzed using linear regression model.

RESULTS

In both 3D and 2D SWE, larger size and presence of lymphovascular invasion were independent factors influencing higher mean elasticity on multivariate analyses (all p values<0.05).

CONCLUSIONS

Using either 3D or 2D SWE, higher mean elasticity values are associated with poor prognostic factors of IBC.

Role of Sonography in Predicting the Hormone Receptor Status of Breast Cancer: A Prospective Study

The purpose of this study was to determine the predictive value of sonography in identifying the receptor status of breast cancer. Sonograms were performed on 73 patients with breast cancer by two experienced sonologists, and the sonographic features such as tumor size, shape, margins, vascularity, posterior acoustic features, and architectural distortion of surrounding tissues were studied. These were then correlated with the receptor status, that is, triple negative versus non-triple negative. Triple-negative breast cancer was associated with large size, circumscribed margins, posterior acoustic enhancement, high vascularity, and lack of architectural distortion. Non-triple-negative breast cancer tumors revealed smaller sizes with spiculated margins, posterior shadowing, lower vascularity, and architectural distortion of surrounding tissues. Sonography revealed a high sensitivity and specificity (84.0% and 81.2%, respectively) on multivariate analysis for identifying receptor status prospectively. Interobserver agreement was also good. In conclusion, sonography may play a valuable role in prospectively predicting the receptor status in breast cancer and can serve as a potential tool for detecting triple-negative cancer.

Histological Grade and Immunohistochemical Biomarkers of Breast Cancer: Correlation to Ultrasound Features

OBJECTIVES

The purpose of this study is to correlate various features of breast cancers on ultrasound to their histological grade and immunohistochemical biomarkers.

METHODS

Seventy-three patients with 77 invasive breast cancers, diagnosed between August 2011 and December 2014, were included in this prospective analysis. Margin, posterior features, shape, and vascularity were determined from ultrasound and classified according to the Breast Imaging Reporting and Data System lexicon. Histological grade, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status (positive [+] or negative [-]) were determined from surgical pathology reports. The cancers were categorized into low grade (grades 1 or 2) and high grade (grade 3). Correlation of ultrasound features of the cancers to their histological grade and receptor status was performed.

RESULTS

There were 47 low-grade and 29 high-grade cancers. There was a significant difference in margin and posterior features between the low and high grade, ER + and ER-, and PR + and PR- (all P < .05), but not between HER2 + and HER2- cancers (both P > .05). There was no significant difference in shape and vascularity among the different subtypes (all P > .05). Spiculated margin was significantly associated with low-grade, ER+, PR + status; angular margin with high grade; microlobulated margin with ER- status; shadowing with PR + status; and enhancement with high grade, ER- status (all P < .05, all odds ratios ≥ 3.94).

CONCLUSIONS

There was significant association of margin and posterior features of breast cancers with their histological grade and receptor status.

Radiomics Analysis on Ultrasound for Prediction of Biologic Behavior in Breast Invasive Ductal Carcinoma

INTRODUCTION

In current clinical practice, invasive ductal carcinoma is always screened using medical imaging techniques and diagnosed using immunohistochemistry. Recent studies have illustrated that radiomics approaches provide a comprehensive characterization of entire tumors and can reveal predictive or prognostic associations between the images and medical outcomes. To better reveal the underlying biology, an improved understanding between objective image features and biologic characteristics is urgently required.

PATIENTS AND METHODS

A total of 215 patients with definite histologic results were enrolled in our study. The tumors were automatically segmented using our phase-based active contour model. The high-throughput radiomics features were designed and extracted using a breast imaging reporting and data system and further selected using Student's t test, interfeature coefficients and a lasso regression model. The support vector machine classifier with threefold cross-validation was used to evaluate the relationship.

RESULTS

The radiomics approach demonstrated a strong correlation between receptor status and subtypes (P < .05; area under the curve, 0.760). The appearance of hormone receptor-positive cancer and human epidermal growth factor receptor 2-negative cancer on ultrasound scans differs from that of triple-negative cancer.

CONCLUSION

Our approach could assist clinicians with the accurate prediction of prognosis using ultrasound findings, allowing for early medical management and treatment.

Sonographic features that can be used to differentiate between small triple-negative breast cancer and fibroadenoma

PURPOSE

Our study investigated whether any sonographic findings could be useful for differentiating between small triple-negative breast cancer (TNBC) and fibroadenoma.

METHODS

This retrospective study was approved by our Institutional Review Board, which waived the requirement for patient consent. From January 2009 to December 2010, the sonographic features of 181 pathologically proven TNBC tumors and 172 fibroadenomas measuring less than or equal to 2 cm in the longest dimension were reviewed and analyzed according to the fifth edition of the Breast Imaging Reporting and Data System (BI-RADS) lexicon. Mean tumor roundness was also measured using in-house software.

RESULTS

The median longest lesion dimension was 16 mm (range, 13 to 18 mm) in TNBCs and 13 mm (range, 10 to 16 mm) in fibroadenomas. In comparison to fibroadenomas, small TNBC tumors presented with a higher incidence of irregular shapes (66.9%), noncircumscribed margins (91.7%), hypoechoic echotexture (59.1%), posterior acoustic enhancement (65.2%), and associated features (24.4%). Most TNBCs were classified as BI-RADS category 4 (65.2%) or 5 (28.2%). The mean tumor roundness of small TNBCs was greater than that of fibroadenomas (60%±12% vs. 53%±13%). Multivariate analysis showed that older patient age, irregular shape, nonparallel orientation, posterior acoustic enhancement, associated features, a BI-RADS final assessment category of 4 or 5, and greater tumor roundness were significant independent factors indicative of TNBCs.

CONCLUSION

TNBC tumors tend to demonstrate more suspicious sonographic features and greater tumor roundness than fibroadenomas. These features may have the potential to help differentiate between small TNBCs and fibroadenomas.

Breast cancer in the 21st century: from early detection to new therapies

The analysis of the causes that have given rise to a change in tendency in the incidence and mortality rates of breast cancer in the last few decades generates important revelations regarding the role of breast screening, the regular application of adjuvant therapies and the change of risk factors. The benefits of early detection have been accompanied by certain adverse effects, even in terms of an excessive number of prophylactic mastectomies. Recently, several updates have been published on the recommendations in breast cancer screening at an international level. On the other hand, the advances in genomics have made it possible to establish a new molecular classification of breast cancer. Our aim is to present an updated overview of the epidemiological situation of breast cancer, as well as some relevant issues from the point of view of diagnosis, such as molecular classification and different strategies for both population-based and opportunistic screening.

Mammography and ultrasound effective features in differentiating basal-like and normal-like subtypes of triple negative breast cancer

The aim of our study was to find effective features of mammography and ultrasound in differentiating Basal-like breast cancer (BBC) and Normal-like breast cancer (NBC), two subtypes of triple negative breast cancer (TNBC). From January 2014 to March 2017, we retrospectively reviewed 91 patients who were pathologically confirmed as TNBC. According to immunohistochemical cytokeratin 5/6 (CK5/6) and Epidermal Growth Factor Receptor (EGFR), TNBCs were classified into BBCs group and NBCs group. Both CK5/6 and EGFR were negative defined to be NBC, whereas if any of CK5/6 or EGFR was positive then defined as BBC. BBCs group concluded 65 (71.4%) cases and NBCs group concluded26 (28.6%) cases. Ultrasound images and mammograms were reevaluated by breast imaging experts according to the breast imaging reporting and data system (BI-RADS) 4th edition. On mammography, masses margins had significant differences between BBCs group and NBCs group (P = 0.024). Most BBCs margins exhibited microlobulated (30/64, 46.9%) or spiculated (25/64, 39.0%), whereas most NBCs margins exhibited microlobulated (17/23, 73.9%). On ultrasound, BBCs were more frequently to present as larger than 20mm lesions (52/65, 80.0%) and more likely to have angular or spiculated margins (35/65, 53.8%), additionally, compared with NBCs, BBCs were less likely to have calcification (1/65, 1.5%). Other mammography and ultrasound features showed no significant differences between the two groups. In conclusion, we have found some effective features of mammography and ultrasound that could be helpful in differentiating BBC and NBC, which will provide some useful references for clinical diagnosis and treatment.

Correlation Factors Analysis of Breast Cancer Tumor Volume Doubling Time Measured by 3D-Ultrasound

BACKGROUND Tumor volume doubling time (TVDT) is relatively important for breast cancer diagnosis and prognosis evaluation. This study aimed to analyze the related factors that may affect the TVDT of breast cancer by three-dimensional ultrasound (3D-US). MATERIAL AND METHODS A total of 69 breast cancer patients were selected. 3D-US was applied to measure the volume of breast lumps diagnosed as BI-RADS-US 4A by conventional ultrasound. TVDT was calculated according to the formula TVDT=DT×log2/log(V2/V1). Multiple linear regression analysis was performed to analyze the factors influencing breast cancer TVDT. RESULTS The mean and median TVDT were 185±126 (range 66-521) and 164 days, respectively. TVDT showed no statistical significance according to regular shape, coarse margin, spicule sign, peripheral hyperechoic halo, microcalcification, and different posterior echo characteristics (P>0.05). Patients grouped by age, axillary lymphatic metastasis, histological differentiation, and Nottingham prognostic index (NPI) score exhibited significantly different TVDT (P<0.05). On the contrary, patients with different menstrual conditions, breast cancer family history, or pathological types presented similar TVDT (P>0.05). TVDT was obviously different in breast cancer with different ER, PR, Ki-67, and molecular subtyping but not HER2 expression. Multivariate analysis revealed that NPI score, axillary lymphatic metastasis, Ki-67, and molecular subtyping were risk factors of TVDT in breast cancer (P<0.05). CONCLUSIONS Breast cancer TVDT was significantly correlated with NPI score, axillary lymphatic metastasis, Ki-67, and molecular subtyping. Triple-negative breast cancer exhibited the most rapid growth.

Breast Cancer Detected at Screening US: Survival Rates and Clinical-Pathologic and Imaging Factors Associated with Recurrence

Purpose To determine the survival rates and clinical-pathologic and imaging factors associated with recurrence in women with breast cancer detected at screening ultrasonography (US). Materials and Methods This study was approved by the institutional review board, and the requirement to obtain informed consent was waived. A retrospective review of the databases of four institutions identified 501 women (median age, 47 years; range, 27-74 years) with breast cancer (425 invasive cancers and 76 ductal carcinoma in situ) detected at screening US between January 2004 and March 2011. Five-year overall survival (OS) and recurrence-free survival (RFS) rates were estimated, and the clinical-pathologic and imaging data were collected. Multivariate analysis was performed by using Cox proportional hazard regression to determine factors associated with recurrence. Results At a median follow-up of 7.0 years (range, 5.0-12.1 years), 15 (3.0%) recurrences were detected: five in ipsilateral breast and 10 in contralateral breast. The 5-year OS and RFS rates were 100% and 98.0% (95% confidence interval [CI]: 96.8%, 99.2%), respectively. In patients with invasive cancers, age younger than 40 years (hazard ratio: 3.632 [95% CI: 1.099, 11.998]; P = .032), the triple-negative subtype (hazard ratio: 7.498 [95% CI: 2.266, 24.816]; P = .001), and Breast Imaging Reporting and Data System (BI-RADS) category 4A lesions (hazard ratio: 5.113 [95% CI: 1.532, 17.195]; P = .008) were associated with recurrence. Conclusion Women with breast cancers detected at screening US have excellent outcomes, with a 5-year RFS rate of 98.0%. However, in patients with invasive breast cancer, age younger than 40 years, the triple-negative subtype, and BI-RADS category 4A lesions were associated with recurrence. ^© RSNA, 2017 Online supplemental material is available for this article.

Imaging Surveillance After Primary Breast Cancer Treatment

OBJECTIVE

Current clinical guidelines are consistent in supporting annual mammography for women after treatment of primary breast cancer. Surveillance imaging beyond standard digital mammography, including digital breast tomosynthesis (DBT), breast ultrasound, and MRI, may improve outcomes. This article reviews the evidence on the performance and effectiveness of breast imaging modalities available for surveillance after treatment of sporadic unilateral primary breast cancer and identifies additional factors to be considered when selecting an imaging surveillance regimen.

CONCLUSION

Evidence review supports the use of mammography for surveillance after primary breast cancer treatment. Variability exists in guideline recommendations for surveillance initiation, interval, and cessation. DBT offers the most promise as a potential modality to replace standard digital mammography as a front-line surveillance test; a single published study to date has shown a significant decrease in recall rates compared with standard digital mammography alone. Most guidelines do not support the use of whole-breast ultrasound in breast cancer surveillance, and further studies are needed to define the characteristics of women who may benefit from MRI surveillance. The emerging evidence about surveillance imaging outcomes suggests that additional factors, including patient and imaging characteristics, tumor biology and gene expression profile, and choice of treatment, warrant consideration in selecting personalized posttreatment imaging surveillance regimens.

The role of ultrasonographic findings to predict molecular subtype, histologic grade, and hormone receptor status of breast cancer

PURPOSE

The correlation between imaging findings and pathologic characteristics of tumors may provide information for diagnosis and treatment of cancer. The aim of this study is to determine whether ultrasound features of breast cancer are associated with molecular subtype, histologic grade, and hormone receptor status, as well as assess the predictive value of these features.

METHODS

A total of 201 consecutive invasive breast cancer patients were reviewed from the database according to the Breast Imaging and Reporting Data System (BI-RADS). Tumor margins were classified as circumscribed and noncircumscribed. Noncircumscribed group was divided into indistinct, spiculated, angular, and microlobulated. The posterior acoustic features were divided into four categories: shadowing, enhancement, no change, and mixed pattern.

RESULTS

Tumors with posterior shadowing were more likely to be of nontriple negative subtype (odds ratio [OR], 7.42; 95% CI, 2.10-24.99; P = 0.002), low histologic grade (grade 1 or 2 vs. grade 3: OR, 2.42; 95% CI, 1.34-4.35; P = 0.003) and having at least one positive receptor (OR, 3.36; 95% CI, 1.55-7.26; P = 0.002). Tumors with circumscribed margins were more often triple-negative subtype (OR, 6.72; 95% CI, 2.56-17.65; P < 0.001), high grade (grade 3 vs. grade 1 or 2: OR, 5.42; 95% CI, 2.66-11.00; P < 0.001) and hormone receptor negative (OR, 4.87; 95% CI, 2.37-9.99; P < 0.001).

CONCLUSION

Sonographic features are strongly associated with molecular subtype, histologic grade, and hormone receptor status of the tumor. These findings may separate triple-negative breast cancer from other molecular subtypes.

Imaging features of automated breast volume scanner: Correlation with molecular subtypes of breast cancer

OBJECTIVES

To investigate the correlation between the imaging features obtained by an automated breast volume scanner (ABVS) and molecular subtypes of breast cancer.

METHODS

We examined 303 malignant breast tumours by ABVS for specific imaging features and by immunohistochemical analysis to determine the molecular subtype. ABVS imaging features, including retraction phenomenon, shape, margins, echogenicity, post-acoustic features, echogenic halo, and calcifications were analysed by univariate and multivariate logistic regression analyses to determine the significant predictive factors of the molecular subtypes.

RESULTS

By univariate logistic regression analysis, the predictive factors of the Luminal-A subtype (n=128) were retraction phenomenon (odds ratio [OR]=10.188), post-acoustic shadowing (OR=5.112), and echogenic halo (OR=3.263, P<0.001). The predictive factors of the Human-epidermal-growth-factor-receptor-2-amplified subtype (n=39) were calcifications (OR=6.210), absence of retraction phenomenon (OR=4.375), non-mass lesions (OR=4.286, P<0.001), absence of echogenic halo (OR=3.851, P=0.035), and post-acoustic enhancement (OR=3.641, P=0.008). The predictors for the Triple-Negative subtype (n=47) were absence of retraction phenomenon (OR=5.884), post-acoustic enhancement (OR=5.255, P<0.001), absence of echogenic halo (OR=4.138, P=0.002), and absence of calcifications (OR=3.363, P=0.001). Predictors for the Luminal-B subtype (n=89) had a relatively lower association (OR≤2.328). By multivariate logistic regression analysis, retraction phenomenon was the strongest independent predictor for the Luminal-A subtype (OR=9.063, P<0.001) when present and for the Triple-Negative subtype (OR=4.875, P<0.001) when absent.

CONCLUSIONS

ABVS imaging features, especially retraction phenomenon, have a strong correlation with the molecular subtypes, expanding the scope of ultrasound in identifying breast cancer subtypes with confidence.

Immunohistochemical Subtypes of Breast Cancer: Correlation with Clinicopathological and Radiological Factors

BACKGROUND

The relationship between biomarkers and imaging features is important because imaging findings can predict molecular features.

OBJECTIVES

To investigate the relationship between clinicopathologic and radiologic factors and the immunohistochemical (IHC) profiles associated with breast cancer.

PATIENTS AND METHODS

From December 2004 to September 2013, 200 patients (mean age, 56 years; range, 29 - 82 years) were diagnosed with breast cancer and underwent surgery at our institution. Their medical records were reviewed to determine age, symptom presence, mammographic findings (including mass, asymmetry, microcalcifications, or negativity), sonographic Breast Imaging-Reporting and Data System (BI-RADS) category, pathologic type of cancer (invasive ductal, mucinous, medullary, or papillary carcinoma), histologic grade, T-stage, and IHC subtypes. Based on the IHC profiles, tumor subtypes were classified as luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) enriched, or triple-negative (TN) cancers. Using univariate and multivariate logistic regression analyses, we looked for correlations between four IHC subtypes and two IHC subtypes (TN and non-triple negative [non-TN]) and clinicopathologic and radiologic factors, respectively.

RESULTS

Based on our univariate analyses with the four subtypes, the TN subtype showed a higher incidence of masses on mammography compared to the other subtypes (P = 0.037), and the TN subtype also tended to have the highest histologic grade among the subtypes (P < 0.001). With regard to the two IHC subtypes, the TN subtype had a significant association with medullary cancer (P = 0.021), higher histologic grade (grade 3; P < 0.001), and higher T stage (T2; P = 0.027) compared to the non-TN subtypes. In a multivariate logistic regression analysis of the clinicoradiologic factors compared to luminal A, the HER2 subtype had a significant association with BI-RADS category 4b (odds ratio [OR], 9.005; 95% confidence interval [CI], 1.414 - 57.348; P = 0.020) and borderline significance with category 4c (OR, 4.669; 95% CI, 0.970 - 22.468; P = 0.055). In a multivariate logistic regression analysis of the clinicoradiologic factors associated with the non-TN subtypes, the TN subtype was significantly correlated with medullary carcinoma (OR, 7.092; 95% CI, 1.149 - 43.772; P = 0.035).

CONCLUSION

These results suggest that patients with the TN subtypes are more likely to have higher-histologic-grade tumors and medullary cancer. The HER2 subtype was typically associated with a higher BI-RADS category.

Differences in Multi-Modal Ultrasound Imaging between Triple Negative and Non-Triple Negative Breast Cancer

The objective of this study was to identify multi-modal ultrasound imaging parameters that could potentially help to differentiate between triple negative breast cancer (TNBC) and non-TNBC. Conventional ultrasonography, ultrasound strain elastography and 3-D ultrasound (3-D-US) findings from 50 TNBC and 179 non-TNBC patients were retrospectively reviewed. Immunohistochemical examination was used as the reference gold standard for cancer subtyping. Different ultrasound modalities were initially analyzed to define TNBC-related features. Subsequently, logistic regression analysis was applied to TNBC-related features to establish models for predicting TNBC. TNBCs often presented as micro-lobulated, markedly hypo-echoic masses with an abrupt interface (p = 0.015, 0.0015 and 0.004, compared with non-TNBCs, respectively) on conventional ultrasound, and showed a diminished retraction pattern phenomenon in the coronal plane (p = 0.035) on 3-D-US. Our findings suggest that B-mode ultrasound and 3-D-US in multi-modality ultrasonography could be a useful non-invasive technique for differentiating TNBCs from non-TNBCs.

Association between sonographic appearances of breast cancers and their histopathologic features and biomarkers

PURPOSE

The purpose of this study was to investigate potential associations between invasive breast cancer sonographic (US) findings and histopathologic patterns and biomarkers.

METHODS

One hundred consecutive women with invasive breast cancer treated in the Breast Diagnostic Center of Brotzu Hospital in Cagliari, Italy, from January to October 2013, were retrospectively evaluated. Two experienced breast radiologists independently evaluated hard copies of US examinations performed during the US-guided biopsy procedure. Tumor characteristics were assessed by using the BI-RADS US lexicon. For each patient, the results of histopathologic examination, tumor grading, hormone-receptor status, HER2, and Ki67 were considered. US characteristics were compared with histopathologic features and biomarkers. Statistical analysis was performed.

RESULTS

Low-grade tumors were statistically significantly associated with spiculated margins (p = 0.002) and hyperechoic halos (p < 0.001). High-grade tumors were associated with abrupt interfaces, nonspiculated margins, and absence of posterior acoustic shadowing. Malignant breast masses with spiculated margins were significantly associated with hormone-receptor positivity (p = 0.009). The most frequent tumor grade was G3 in the HER2 + and triple-negative subgroups. Patients with G3 tumors were significantly younger than those with G1 or G2 disease (51.3 ± 9.5 years versus 58.7 ± 12.6 years; p = 0.004).

CONCLUSIONS

Histopathologic patterns and breast cancer biomarkers determine differences in US imaging that can guide radiologists in better understanding the development of breast cancer and its prognosis.

Molecular classification of infiltrating breast cancer: toward personalized therapy

Breast cancer is a heterogeneous disease, which comprises several molecular and genetic subtypes, each with characteristic clinicobiologic behavior and imaging patterns. Traditional classification of breast cancer is based on the histopathologic features but offers limited prognostic value. Novel molecular characterization of breast cancer with cellular markers has allowed a new classification that offers prognostic value, with predictive categories of disease aggressiveness. These molecular signatures also open the door to personalized therapeutic options, with new receptor-targeted therapies. For example, invasive cancer subtypes such as the luminal A and B subtypes show better prognosis and response to hormone receptor-targeted therapies compared with the triple-negative subtypes; on the other hand, triple-negative tumors respond better than luminal tumors to chemotherapy. Tumors that display amplification of the oncogene ERBB2 (also known as the HER2/neu oncogene) respond to drugs directed against this oncogene, such as trastuzumab. The imaging aspects of tumors correlate with molecular subgroups, as well as other pathologic features such as nuclear grade. Smooth tumor margins at mammography may be suggestive of a triple-negative breast cancer, and a human epidermal growth factor receptor 2 (HER2)-positive tumor is characteristically a spiculated mass with calcifications. Low-grade ductal carcinoma in situ (DCIS) is better detected with mammography, although magnetic resonance (MR) imaging may allow better characterization of high-grade DCIS. MR imaging diffusion sequences show higher values for the apparent diffusion coefficient for triple-negative and HER2-positive subtypes, compared with luminal A and B tumors. MR imaging is also a useful tool in the prediction of tumor response after chemotherapy, especially for triple-negative and HER2-positive subtypes.

Combined Use of Ultrasound Elastography and B-Mode Sonography for Differentiation of Benign and Malignant Circumscribed Breast Masses

OBJECTIVES

To evaluate the diagnostic performance of combined B-mode sonography and ultrasound elastography for differentiation between benign and malignant breast masses with circumscribed margins.

METHODS

We analyzed 109 pathologically proven circumscribed breast masses. Two radiologists retrospectively reviewed B-mode sonograms and elastograms in consensus. Based on the American College of Radiology Breast Imaging Reporting and Data System, we determined categories of the masses on B-mode sonography. Elastographic scores were assessed by a 3-point scale (negative, 0; equivocal, 1; and positive, 2). When the elastographic score for a lesion was 0 or 2, we downgraded or upgraded the B-mode category, respectively; thus, the reclassified Breast Imaging Reporting and Data System category was defined as the "reclassification category." Mean category values for benign and malignant lesions were compared by a Student t test. The diagnostic performance of B-mode, elastographic, and reclassification assessments was compared by receiver operating characteristic curve analysis.

RESULTS

The mean B-mode category (2.5 versus 1.7), elastographic score (1.7 versus 0.8), and reclassification category (3.2 versus 1.6) were significantly higher in malignant than benign lesions (P < .001). The area under the curve for reclassification assessment was significantly higher than that for B-mode sonography (0.916 versus 0.795; P < .05). With a cutoff value between 1 and 2, the specificity was increased from 26.5% to 42.9% after reclassification.

CONCLUSIONS

For differentiation between benign and malignant circumscribed breast masses, combined use of B-mode sonography and elastography could provide a better diagnostic performance than B-mode sonography alone.

Microcalcification-Associated Breast Cancer: Presentation, Successful First Excision, Long-Term Recurrence and Survival Rate

INTRODUCTION

In this study we evaluated mammographic, histological and immunohistochemical findings for microcalcification-associated breast cancer with regards to breast-conserving therapy, recurrence and survival rate.

PATIENTS AND METHODS

We retrospectively analyzed 99 consecutive, non-palpable and microcalcification-associated breast cancers (94 women) that were treated surgically between January 2002 and December 2003 at a national academic breast cancer center. Calcifications were classified according to the Breast Imaging Reporting and Data System (BI-RADS). Descriptors, surgical outcome and histological findings were assessed. Recurrences and survival rates were evaluated based on medical records, standardized patient questionnaires and/or contacting the physician.

RESULTS

42 of the 99 lesions (42.4%) were invasive carcinomas, 57 (57.6%) were pure ductal carcinoma in situ (DCIS). 6 out of 99 (6.1%) lesions were triple negative, and 29 (29.3%) were HER2/neu positive. Successful first excision rate was 76/99 lesions (76.8%). Breast conservation was achieved in 73.7% (73/99). 10 women showed local recurrences without negatively impacting survival. The recurrences included round/punctate, amorphous, fine pleomorphic, and fine linear or fine-linear branching descriptors. The breast cancer-specific long-term survival rate was 91/94 (96.8%) for a mean follow-up of 81.4 months. The 3 patients who died due to breast carcinoma showed fine pleomorphic calcifications, and had nodal-positive invasive carcinoma at diagnosis.

CONCLUSION

Microcalcification-associated breast cancers are frequently treated with breast-conserving therapy. Continuous clinical and mammographic follow-up is recommended for all descriptors.

False positive or negative results of shear-wave elastography in differentiating benign from malignant breast masses: analysis of clinical and ultrasonographic characteristics

BACKGROUND

Shear-wave elastography (SWE) has the potential to improve diagnostic performance of conventional ultrasound (US) in differentiating benign from malignant breast masses.

PURPOSE

To investigate false positive or negative results of SWE in differentiating benign from malignant breast masses and to analyze clinical and imaging characteristics of the masses with false SWE findings.

MATERIAL AND METHODS

From May to October 2013, 166 breast lesions of 164 consecutive women (mean age, 45.3 ± 10.1 years) who had been scheduled for biopsy were included. Conventional US and SWE were performed in all women before biopsy. Clinical, ultrasonographic morphologic features and SWE parameters (pattern classification and standard deviation [SD]) were recorded and compared with the histopathology results. Patient and lesion factors in the "true" and "false" groups were compared.

RESULTS

Of the 166 masses, 118 (71.1%) were benign and 48 (28.9%) were malignant. False SWE features were more frequently observed in benign masses. False positive rates of benign masses and false negative rates of malignancy were 53% and 8.2%, respectively, using SWE pattern analysis and were 22.4% and 10.3%, respectively, using SD values. A lesion boundary of the masses on US (P = 0.039) and younger patient age (P = 0.047) were significantly associated with false SWE findings.

CONCLUSION

These clinical and ultrasonographic features need to be carefully evaluated in performance and interpretation of SWE examinations.

An overview of triple-negative breast cancer

PURPOSE

Triple-negative breast cancer (TNBC) is a heterogeneous group of tumors comprising various breast cancers simply defined by the absence of estrogen receptor, progesterone receptor and overexpression of human epidermal growth factor receptor 2 gene. In this review, we discuss the epidemiology, risk factors, clinical characteristics and prognostic variables of TNBC, and present the summary of recommended treatment strategies and all other available treatment options.

METHODS

We performed a systematic literature search using Medline and selected those articles which seemed relevant for this review. In addition, the ClinicalTrials.gov was also scanned for ongoing trials.

RESULTS

TNBC accounts for 10-20 % of all invasive breast cancers and has been found to be associated with African-American race, younger age, higher grade and mitotic index, and more advanced stage at diagnosis. Locoregional treatment is similar to other invasive breast cancer subtypes and involves surgery-mastectomy with or without adjuvant radiotherapy or breast conservation followed by adjuvant radiotherapy. Due to lack of drug-targetable receptors, chemotherapy is the only recommended systemic treatment to improve disease outcome. TNBC is sensitive to chemotherapy as demonstrated by high pathological complete response rates achieved after neoadjuvant chemotherapy, and this approach also allows for breast-conserving surgery. The peak risk of relapse is at 3 years after surgery, thereafter recurrence risk rapidly decreases. Survival after metastatic relapse is shorter as compared to other breast cancer subtypes, treatment options are few and response rates are poor and lack durability. Important molecular characteristics have now been identified that can subdivide this group of breast cancers further and can provide alternative systemic therapies.

CONCLUSIONS

To improve therapeutic outcome of TNBC, reliable predictive biomarkers and newer drugs against the known molecular pathways are required.

Elastographic features of triple negative breast cancers

OBJECTIVES

To evaluate shear-wave elastographic (SWE) features of triple negative breast cancers (TNBC) and determine useful discriminators from other types of invasive breast cancers.

METHODS

SWE features of 26 TNBC were reviewed and compared to 32 non-TNBC. Qualitative SWE features of lesion colour appearance, shape and homogeneity were analysed. Quantitative features were measured: mean (El mean), maximum (El max) and minimum (El min) elasticity value of the stiffest portion of the mass, mean elasticity of the surrounding tissue (El mean surr) and lesion to fat elasticity ratio (E ratio).

RESULTS

TNBC are more often regularly shaped (57.7 % vs. 6.2 %), while non-TNBC are more commonly red (93.7 % vs 42.3 %) and heterogeneous (68.7 % vs 42.3 %). The stiffness of TNBC is significantly lower compared to non-TNBC. The two groups could be distinguished on the basis of El max (p = 0.001), El mean (p = 0.001), El min (p = 0.001) and E ratio (p = 0.0017). Lesion to fat elasticity ratio in TNBC group was statistically significantly lower than in the non-TNBC control group (p = 0.009).

CONCLUSIONS

TNBC often demonstrate benign morphological features, are softer on SWE and have a lower lesion to fat stiffness ratio compared to the other, more common types of invasive breast cancers.

KEY POINTS

• TNBC often demonstrate benign morphological features on SWE. • TNBC present on elastography mostly as red, regularly shaped, heterogeneous lesions. • TNBC are less stiff compared to other invasive breast cancers. • TNBC have lower lesion to fat stiffness ratio than other breast cancers.

Identifying ultrasound and clinical features of breast cancer molecular subtypes by ensemble decision

Breast cancer is molecularly heterogeneous and categorized into four molecular subtypes: Luminal-A, Luminal-B, HER2-amplified and Triple-negative. In this study, we aimed to apply an ensemble decision approach to identify the ultrasound and clinical features related to the molecular subtypes. We collected ultrasound and clinical features from 1,000 breast cancer patients and performed immunohistochemistry on these samples. We used the ensemble decision approach to select unique features and to construct decision models. The decision model for Luminal-A subtype was constructed based on the presence of an echogenic halo and post-acoustic shadowing or indifference. The decision model for Luminal-B subtype was constructed based on the absence of an echogenic halo and vascularity. The decision model for HER2-amplified subtype was constructed based on the presence of post-acoustic enhancement, calcification, vascularity and advanced age. The model for Triple-negative subtype followed two rules. One was based on irregular shape, lobulate margin contour, the absence of calcification and hypovascularity, whereas the other was based on oval shape, hypovascularity and micro-lobulate margin contour. The accuracies of the models were 83.8%, 77.4%, 87.9% and 92.7%, respectively. We identified specific features of each molecular subtype and expanded the scope of ultrasound for making diagnoses using these decision models.

The differences in ultrasound and clinicopathological features between basal-like and normal-like subtypes of triple negative breast cancer

Purpose

The aim of this study was to identify the ultrasound features and clinicopathological characteristics of basal-like subtype of triple negative breast cancers (TNBCs).

Materials and Methods

This study was approved by the ethical board of the Second Affiliated Hospital of Harbin Medical University. The patients’ clinicopathological information was available. The ultrasound features of 62 tumors from 62 TNBC patients were interpreted. The immunohistochemical results of cytokertain5/6 (CK5/6) and Epidermal Growth Factor Receptor (EGFR) were used to classify the tumor into basal-like and normal-like groups. The association of the ultrasound features interpreted by experienced ultrasound doctors with the immunohistochemical classification was studied.

Results

Of the 62 TNBC cases, 42 (67.7%) exhibited the basal-like phenotype and 20 (32.3%) exhibited the normal-like phenotype based on the immunohistochemical CK5/6 and EGFR markers. Of all the tumors, 90.3% were invasive carcinomas. The basal-like tumors were significantly associated with a maximum diameter on ultrasound of more than 20 mm (36, 85.7%) (P = 0.0014). The normal-like tumors usually exhibited lateral shadows (15, 75%) (P = 0.0115) as well as microlobulated margins (12, 60%) (P = 0.0204) compared to the basal-like subtype. Other ultrasound features showed no significant differences between the two groups.

Conclusions

Although ultrasound cannot yet be used to differentiate between the basal-like subtype and normal-like subtype of TNBC, ultrasound can be used to provide some useful information to the clinicians.

Mammographic and sonographic features of triple-negative invasive carcinoma of no special type

The aim of this study was to compare the mammography, ultrasound (US) and histologic features of triple-negative (TN) invasive carcinoma of no special type (NST) to non-TN invasive carcinoma of NST. The second aim was to assess whether the distinct imaging characteristics of TN breast cancer would persist after controlling for the histologic features. A total of 344 invasive carcinomas of NST in 337 patients from January 2007 to February 2008 were included in this study. Two radiologists retrospectively reviewed the mammography and US findings using the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) lexicon and our institution's criteria. On mammography, TN invasive carcinoma of NST most commonly presented as a mass with round shape and non-spiculated margin. On US, it was more likely to have internal hypoechogenicity, an abrupt boundary and posterior acoustic enhancement. TNBC lacked major suspicious imaging findings such as an irregular shape, spiculated margin and calcification.

The 2014 Society of Surgical Oncology Susan G. Komen for the Cure Symposium: triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an operational term that refers to a heterogeneous collection of breast cancers lacking expression of estrogen receptor (ER), progesterone receptor, and HER2. These tumors account for 12-17 % of all breast cancers, preferentially affect young women, are more frequent in women of African and Hispanic descent, and are enriched in the population of patients diagnosed with "interval cancers." TNBCs account for the majority of breast cancers arising in BRCA1 germline mutation carriers (approximately 80%), and approximately 11-16% of all TNBCs harbor BRCA1 or BRCA2 germline mutations. Well-known risk factors for ER-positive cancers, such as reproductive history and hormonal factors, do not appear to have the same correlations for TNBC, and histologic risk factors for TNBC have not been identified. Patients with TNBC have a higher risk of both local and distant recurrence, but this is not mitigated by bigger surgery, and standard criteria should be used to select the approach to local therapy in these patients. Although platinum drugs have shown promise in the treatment of TNBC, standard chemotherapy remains the standard of care outside of a clinical trial.

Non-mass-like breast lesions at ultrasonography: feature analysis and BI-RADS assessment

OBJECTIVE

To analyze the features of non-mass-like (NML) breast lesions on ultrasound (US) and determine their corresponding malignancy rate and to stratify these lesion patterns according to US BI-RADS categories.

MATERIALS AND METHODS

One hundred sixty-four consecutive lesions were retrospectively classified into four types according to the US features, the corresponding positive predictive values (PPVs) were obtained. Clinical, imaging, and histopathological findings were reviewed.

RESULTS

Among the 164 lesions, 39 (24%) were classified as type Ia, 14 (8%) as type Ib, 39 (24%) as type IIa, 19 (12%) as type IIb, 19 (12%) as type III, and 34 (21%) as type IV. The PPVs for malignancy were 21% for type Ia, 79% for type Ib, 10% for type IIa, 58% for type IIb, 16% for type III, and 21% for type IV. All NML lesions were classified as BI-RADS category 4a (type IIa), 4b (type Ia, III and IV) and 4c (type Ib and IIb) according to their PPVs. There was a significantly higher frequency of malignancy among lesions of type Ib and type IIb compared with the other types (P<0.01 for each). Lesions with associated calcifications, presence of abnormal axillary nodes, or a mammographic finding of suspected malignancy had a higher probability of malignancy (P<0.05 for each).

CONCLUSION

US is useful in clarifying the indication for biopsy of NML lesions. The types of US classifications used in our study establish reliable references for the NML patterns when stratified according to the BI-RADS categories.

Association between mammographic features and response to neoadjuvant chemotherapy in locally advanced breast carcinoma

PURPOSE

Mammography is the cornerstone of breast cancer (BC) evaluation. This report investigates whether breast density (BD) and mammographic features of the tumor can provide information on both BC susceptibility to chemotherapy and other clinicopathologic features of locally advanced BC (LA BC).

MATERIALS AND METHODS

We evaluated mammography films and clinicopathological information of patients with LA BC who received neoadjuvant chemotherapy (NAC) followed by tumor resection at the Instituto Nacional de Enfermedades Neoplásicas (INEN) from 2000 to 2011.

RESULTS

We selected 494 LA BC cases. Most cases were at clinical tumor stage 4 (48.5%), node stage 1 (58.8%) and had high histologic grade (53.3%). BI-RADS 1, 2, 3, and 4 BD were found in 16.9%, 22%, 35.7% and 25.1% of patients, respectively. High BD has been associated with younger age (p<0.001), obesity (p=0.017) and no skin infiltration (T3 vs T4) (p=0.018). An association between dusty microcalcifications and HER2 group, as well as between casting microcalcifications and TN BC group (p=0.05) was found. NAC included anthracyclines and taxanes in 422 (85.5%) cases. Miller-Payne pathologic responses 4 and 5 (pCR) in the primary lesion and absence of axillary lymph nodes involvement were found in 15.3% of cases and were associated with younger age (p<0.001) and HG-3 lesions (p<0.001), but not with mammographic images.

CONCLUSION

Mammographic features are associated with specific clinicopathological features of pre-NAC BC lesions but do not predict pCR. The implications and biological reasons for these findings require further study.