The positive predictive value of mammographic signs: a review of 425 non-palpable breast lesions

The dilemma of recalling well-circumscribed masses in a screening population: A narrative literature review and exploration of Dutch screening practice

BACKGROUND

In Dutch breast cancer screening, solitary, new or growing well-circumscribed masses should be recalled for further assessment. This results in cancers detected but also in false positive recalls, especially at initial screening. The aim of this study was to determine characteristics of well-circumscribed masses at mammography and identify potential methods to improve the recall strategy.

METHODS

A systematic literature search was performed using PubMed. In addition, follow-up data were retrieved on all 8860 recalled women in a Dutch screening region from 2014 to 2019.

RESULTS

Based on 15 articles identified in the literature search, we found that probably benign well-circumscribed masses that were kept under surveillance had a positive predictive value (PPV) of 0-2%. New or enlarging solitary well-circumscribed masses had a PPV of 10-12%. In general the detected carcinomas had a favorable prognosis. In our exploration of screening practice, 25% of recalls (2133/8860) were triggered by a well-circumscribed mass. Those recalls had a PPV of 2.0% for initial and 10.6% for subsequent screening. Most detected carcinomas had a favorable prognosis as well.

CONCLUSION

To recognize malignancies presenting as well-circumscribed masses, identifying solitary, new or growing lesions is key. This information is missing at initial screening since prior examinations are not available, leading to a low PPV. Access to prior clinical examinations may therefore improve this PPV. In addition, given the generally favorable prognosis of screen-detected malignant well-circumscribed masses, one may opt to recall these lesions at subsequent screening, if grown, rather than at initial screening.

Evaluation of the peritumoral features using radiomics and deep learning technology in non-spiculated and noncalcified masses of the breast on mammography

OBJECTIVE

To assess the significance of peritumoral features based on deep learning in classifying non-spiculated and noncalcified masses (NSNCM) on mammography.

METHODS

We retrospectively screened the digital mammography data of 2254 patients who underwent surgery for breast lesions in Harbin Medical University Cancer Hospital from January to December 2018. Deep learning and radiomics models were constructed. The classification efficacy in ROI and patient levels of AUC, accuracy, sensitivity, and specificity were compared. Stratified analysis was conducted to analyze the influence of primary factors on the AUC of the deep learning model. The image filter and CAM were used to visualize the radiomics and depth features.

RESULTS

For 1298 included patients, 771 (59.4%) were benign, and 527 (40.6%) were malignant. The best model was the deep learning combined model (2 mm), in which the AUC was 0.884 (P < 0.05); especially the AUC of breast composition B reached 0.941. All the deep learning models were superior to the radiomics models (P < 0.05), and the class activation map (CAM) showed a high expression of signals around the tumor of the deep learning model. The deep learning model achieved higher AUC for large size, age >60 years, and breast composition type B (P < 0.05).

CONCLUSION

Combining the tumoral and peritumoral features resulted in better identification of malignant NSNCM on mammography, and the performance of the deep learning model exceeded the radiomics model. Age, tumor size, and the breast composition type are essential for diagnosis.

Focus on the Predictive Value of Subclassification of Extratumoral Structural Abnormalities for Malignant Nonspiculate and Noncalcified Masses on Digital Mammography

Purpose: To determine the independent risk factors associated with malignant nonspiculate and noncalcified masses (NSNCMs) and evaluate the predictive values of extratumoral structural abnormalities on digital mammography.

Methods: A total of 435 patients were included between January and May 2018. Tumor signs included shape, density, and margin, which were evaluated. Extratumoral signs were classified into extratumoral structural abnormalities (parenchymal and trabecular) and halo; subclassification included contraction, distortion, pushing and atrophy sign of parenchyma, parallel, vertical, and reticular trabecula sign, and narrow and wide halo. Univariate and multivariate analysis was performed. The positive predictive value (PPV) of the independent predictor was calculated, and diagnostic performance was evaluated using the receiver operating characteristic curve.

Results: Of all cases, 243 (55.8%) were benign and 192 (44.2%) were malignant. Extratumoral contraction sign of parenchyma was the strongest independent predictor of malignancy (odds ratio [OR] 36.2, p < 0.001; PPV = 96.6%), followed by parenchymal distortion sign (OR 10.2, p < 0.001; PPV = 92%), parallel trabecula sign (OR 7.2, p < 0.001; PPV = 85.6%), and indistinct margin of tumor (OR 4.3, p < 0.001; PPV =70.9%), and also parenchymal atrophy sign, wide halo, vertical trabecula, age ≥ 47.5 years, irregular shape, and size ≥ 22.5 mm of tumor (OR range, 1.3-4.0; PPV range, 56.6-83.6%). The diagnostic performance of most of the extratumoral signs was between that of indistinct margin and irregular shape of tumor.

Conclusion: The subclassification of extratumoral structural abnormalities has important predictive value for mammographic malignant NSNCM, which should be given more attention.

COVID-19 Unintended Effects on Breast Cancer in Italy After the Great Lockdown

Italy introduced social distancing measures, which limited the spread of COVID-19; all the non-life-threatening treatments have been temporarily suspended, including screening programs. This decision leads to unintended effects on the ability to detected neoplasia in their first stages. Possible future outcomes of the ability to detect new breast cancer cases based on two alternative scenarios show that the reduction in organized screening activities will limit the ability to detect no <3.43% of the new cases; the economic crisis will reduce voluntary screening, increasing the undetected new cases up to 11.73%. Cases diagnosed with delay will show up in their advanced stage along with unknown effects on mortality and health care costs. Global health care policies should be implemented to counterbalance these adverse effects.

Lockdown of Breast Cancer Screening for COVID-19: Possible Scenario

BACKGROUND/AIM

Coronavirus disease is spreading worldwide. Due to fast transmission and high fatality rate drastic emergency restrictions were issued. During the lockdown, only urgent medical services are guaranteed. All non-urgent services, as breast cancer (BC) screening, are temporarily suspended. The potential of breast cancer screening programs in increasing the survival rate and decreasing the mortality rate has been widely confirmed. Suspension could lead to worse outcomes for breast cancer patients. Our study aimed to analyse the data and provide estimates regarding the temporary BC screening suspension.

PATIENTS AND METHODS

Data regarding breast cancer and respective screening programs were achieved through literature research and analysis.

RESULTS

Considering three different scenarios with respect to the lockdown's impact on breast cancer screening, we estimate that approximately 10,000 patients could have a missed diagnosis during these 3 months. Considering a 6-month period, as suggested by the Imperial college model, the number of patients who will not receive a diagnosis will rise to 16,000.

CONCLUSION

Breast cancer screening should be resumed as soon as possible in order to avoid further breast cancer missed diagnosis and reduce the impact of delayed diagnosis.

Characterizing Trastuzumab-Induced Alterations in Intratumoral Heterogeneity with Quantitative Imaging and Immunohistochemistry in HER2+ Breast Cancer

The purpose of this study is to investigate imaging and histology-based measurements of intratumoral heterogeneity to evaluate early treatment response to targeted therapy in a murine model of HER2+ breast cancer. BT474 tumor-bearing mice (N = 30) were treated with trastuzumab or saline and imaged longitudinally with either dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) or 18F-fluoromisonidazole (FMISO) positron emission tomography (PET). At the imaging study end point (day 4 for MRI or 7 for PET), each tumor was excised for immunohistochemistry analysis. Voxel-based histogram analysis was performed on imaging-derived parametric maps (i.e., Ktrans and ve from DCE-MRI, SUV from 18F-FMISO-PET) of the tumor region of interest to measure heterogeneity. Image processing and histogram analysis of whole tumor slice immunohistochemistry data were performed to validate the in vivo imaging findings. Trastuzumab-treated tumors had increased heterogeneity in quantitative imaging measures of cellularity (ve), with a mean Kolmogorov-Smirnov (K-S) distance of 0.32 (P = .05) between baseline and end point distributions. Trastuzumab-treated tumors had increased vascular heterogeneity (Ktrans) and decreased hypoxic heterogeneity (SUV), with a mean K-S distance of 0.42 (P < .01) and 0.46 (P = .047), respectively, between baseline and study end points. These observations were validated by whole-slice immunohistochemistry analysis with mean interquartile range of CD31 distributions of 1.72 for treated and 0.95 for control groups (P = .02). Quantitative longitudinal changes in tumor cellular and vascular heterogeneity in response to therapy may provide evidence for early prediction of response and guide therapy for patients with HER2+ breast cancer.

The Effect of the 2009 USPSTF breast cancer screening recommendations on breast cancer in Michigan: A longitudinal study

In 2009, the revised United States Preventive Services Task Force (USPSTF) guidelines recommended against routine screening mammography for women age 40-49 years and against teaching self-breast examinations (SBE). The aim of this study was to analyze whether breast cancer method of presentation changed following the 2009 USPSTF screening recommendations in a large Michigan cohort. Data were collected on women with newly diagnosed stage 0-III breast cancer participating in the Michigan Breast Oncology Quality Initiative (MiBOQI) registry at 25 statewide institutions from 2006 to 2015. Data included method of detection, cancer stage, treatment type, and patient demographics. In all, 30 008 women with breast cancer detected via mammogram or palpation with an average age of 60.1 years were included. 38% of invasive cancers were identified by palpation. Presentation with palpable findings decreased slightly over time, from 34.6% in 2006 to 28.9% in 2015 (P < .001). Over the 9-year period, there was no statistically significant change in rate of palpation-detected tumors for women age <50 years or ≥50 years (P = .27, .30, respectively). Younger women were more likely to present with palpable tumors compared to older women in a statewide registry. This rate did not increase following publication of the 2009 USPSTF breast cancer screening recommendations.

Radiomic Features Are Superior to Conventional Quantitative Computed Tomographic Metrics to Identify Coronary Plaques With Napkin-Ring Sign

BACKGROUND

Napkin-ring sign (NRS) is an independent prognostic imaging marker of major adverse cardiac events. However, identification of NRS is challenging because of its qualitative nature. Radiomics is the process of extracting thousands of quantitative parameters from medical images to create big-data data sets that can identify distinct patterns in radiological images. Therefore, we sought to determine whether radiomic analysis improves the identification of NRS plaques.

METHODS AND RESULTS

From 2674 patients referred to coronary computed tomographic angiography caused by stable chest pain, expert readers identified 30 patients with NRS plaques and matched these with 30 non-NRS plaques with similar degree of calcification, luminal obstruction, localization, and imaging parameters. All plaques were segmented manually, and image data information was analyzed using Radiomics Image Analysis package for the presence of 8 conventional and 4440 radiomic parameters. We used the permutation test of symmetry to assess differences between NRS and non-NRS plaques, whereas we calculated receiver-operating characteristics' area under the curve values to evaluate diagnostic accuracy. Bonferroni-corrected P<0.0012 was considered significant. None of the conventional quantitative parameters but 20.6% (916/4440) of radiomic features were significantly different between NRS and non-NRS plaques. Almost half of these (418/916) reached an area under the curve value >0.80. Short- and long-run low gray-level emphasis and surface ratio of high attenuation voxels to total surface had the highest area under the curve values (0.918; 0.894 and 0.890, respectively).

CONCLUSIONS

A large number of radiomic features are different between NRS and non-NRS plaques and exhibit excellent discriminatory value.

Cancer heterogeneity and imaging

There is interest in identifying and quantifying tumor heterogeneity at the genomic, tissue pathology and clinical imaging scales, as this may help better understand tumor biology and may yield useful biomarkers for guiding therapy-based decision making. This review focuses on the role and value of using x-ray, CT, MRI and PET based imaging methods that identify, measure and map tumor heterogeneity. In particular we highlight the potential value of these techniques and the key challenges required to validate and qualify these biomarkers for clinical use.

Imaging intratumor heterogeneity: role in therapy response, resistance, and clinical outcome

Tumors exhibit genomic and phenotypic heterogeneity, which has prognostic significance and may influence response to therapy. Imaging can quantify the spatial variation in architecture and function of individual tumors through quantifying basic biophysical parameters such as CT density or MRI signal relaxation rate; through measurements of blood flow, hypoxia, metabolism, cell death, and other phenotypic features; and through mapping the spatial distribution of biochemical pathways and cell signaling networks using PET, MRI, and other emerging molecular imaging techniques. These methods can establish whether one tumor is more or less heterogeneous than another and can identify subregions with differing biology. In this article, we review the image analysis methods currently used to quantify spatial heterogeneity within tumors. We discuss how analysis of intratumor heterogeneity can provide benefit over more simple biomarkers such as tumor size and average function. We consider how imaging methods can be integrated with genomic and pathology data, instead of being developed in isolation. Finally, we identify the challenges that must be overcome before measurements of intratumoral heterogeneity can be used routinely to guide patient care.

Occurrence and Positive Predictive Value of Additional Nonmass Findings for Risk Stratification of Breast Microcalcifications in Mammography

Purpose

To assess the occurrence and positive predictive value of additional nonmass findings to stratify the risk of breast microcalcifications.

Methods

This retrospective evaluation included 278 lesions with vacuum- or image-guided hook-wire biopsy for suspicious microcalcifications. The lesions were categorized into exclusive microcalcifications and microcalcifications with focal asymmetry, tubular density or architectural distortion (ie, nonmass findings). To evaluate the utility of additional nonmass findings for risk stratification, outcome variables were positive predictive values and odds ratios for malignancy and invasive carcinoma.

Results

Forty-five of 278 microcalcification lesions (16%) were associated with nonmass findings: 28 focal asymmetries, 2 tubular densities, and 15 focal asymmetries in conjunction with tubular densities. Architectural distortion was observed in 28 of these cases. The odds ratio for additional nonmass findings relative to exclusive microcalcifications was 5.9 and was statistically significant ( P < .00001). Architectural distortion was the most specific indicator for malignancy and invasiveness, with odds ratios of 6.5 ( P = .0072) and 5.6 ( P = .0214), respectively.

Conclusions

Microcalcifications with nonmass findings were less frequent than exclusive microcalcifications but were more predictive for malignancy. Architectural distortion demonstrated the highest risk of malignancy and invasiveness. Assessment of additional nonmass findings might be useful for further risk stratification of microcalcifications, indications for additional imaging, and pretreatment considerations.

Breast cancer risk prediction model: a nomogram based on common mammographic screening findings

OBJECTIVES

To develop a prediction model for breast cancer based on common mammographic findings on screening mammograms aiming to reduce reader variability in assigning BI-RADS.

METHODS

We retrospectively reviewed 352 positive screening mammograms of women participating in the Dutch screening programme (Nijmegen region, 2006-2008). The following mammographic findings were assessed by consensus reading of three expert radiologists: masses and mass density, calcifications, architectural distortion, focal asymmetry and mammographic density, and BI-RADS. Data on age, diagnostic workup and final diagnosis were collected from patient records. Multivariate logistic regression analyses were used to build a breast cancer prediction model, presented as a nomogram.

RESULTS

Breast cancer was diagnosed in 108 cases (31 %). The highest positive predictive value (PPV) was found for spiculated masses (96 %) and the lowest for well-defined masses (10 %). Characteristics included in the nomogram are age, mass, calcifications, architectural distortion and focal asymmetry.

CONCLUSION

With our nomogram we developed a tool assisting screening radiologists in determining the chance of malignancy based on mammographic findings. We propose cutoff values for assigning BI-RADS in the Dutch programme based on our nomogram, which will need to be validated in future research. These values can easily be adapted for use in other screening programmes.

KEY POINTS

• There is substantial reader variability in assigning BI-RADS in mammographic screening. • There are no strict guidelines linking mammographic findings to BI-RADS categories. • We developed a model (nomogram) predicting the presence of breast cancer. • Our nomogram is based on common findings on positive screening mammograms. • The nomogram aims to assist screening radiologists in assigning BI-RADS categories.

An interactive system for computer-aided diagnosis of breast masses

Although mammography is the only clinically accepted imaging modality for screening the general population to detect breast cancer, interpreting mammograms is difficult with lower sensitivity and specificity. To provide radiologists "a visual aid" in interpreting mammograms, we developed and tested an interactive system for computer-aided detection and diagnosis (CAD) of mass-like cancers. Using this system, an observer can view CAD-cued mass regions depicted on one image and then query any suspicious regions (either cued or not cued by CAD). CAD scheme automatically segments the suspicious region or accepts manually defined region and computes a set of image features. Using content-based image retrieval (CBIR) algorithm, CAD searches for a set of reference images depicting "abnormalities" similar to the queried region. Based on image retrieval results and a decision algorithm, a classification score is assigned to the queried region. In this study, a reference database with 1,800 malignant mass regions and 1,800 benign and CAD-generated false-positive regions was used. A modified CBIR algorithm with a new function of stretching the attributes in the multi-dimensional space and decision scheme was optimized using a genetic algorithm. Using a leave-one-out testing method to classify suspicious mass regions, we compared the classification performance using two CBIR algorithms with either equally weighted or optimally stretched attributes. Using the modified CBIR algorithm, the area under receiver operating characteristic curve was significantly increased from 0.865 ± 0.006 to 0.897 ± 0.005 (p < 0.001). This study demonstrated the feasibility of developing an interactive CAD system with a large reference database and achieving improved performance.

Independent predictors of breast malignancy in screen-detected microcalcifications: biopsy results in 2545 cases

Background:

Mammographic microcalcifications are associated with many benign lesions, ductal carcinoma in situ (DCIS) and invasive cancer. Careful assessment criteria are required to minimise benign biopsies while optimising cancer diagnosis. We wished to evaluate the assessment outcomes of microcalcifications biopsied in the setting of population-based breast cancer screening.

Methods:

Between January 1992 and December 2007, cases biopsied in which microcalcifications were the only imaging abnormality were included. Patient demographics, imaging features and final histology were subjected to statistical analysis to determine independent predictors of malignancy.

Results:

In all, 2545 lesions, with a mean diameter of 21.8 mm (s.d. 23.8 mm) and observed in patients with a mean age of 57.7 years (s.d. 8.4 years), were included. Using the grading system adopted by the RANZCR, the grade was 3 in 47.7% 4 in 28.3% and 5 in 24.0%. After assessment, 1220 lesions (47.9%) were malignant (809 DCIS only, 411 DCIS with invasive cancer) and 1325 (52.1%) were non-malignant, including 122 (4.8%) premalignant lesions (lobular carcinoma in situ, atypical lobular hyperplasia and atypical ductal hyperplasia). Only 30.9% of the DCIS was of low grade.

Mammographic extent of microcalcifications >15 mm, imaging grade, their pattern of distribution, presence of a palpable mass and detection after the first screening episode showed significant univariate associations with malignancy. On multivariate modeling imaging grade, mammographic extent of microcalcifications >15 mm, palpable mass and screening episode were retained as independent predictors of malignancy. Radiological grade had the largest effect with lesions of grade 4 and 5 being 2.2 and 3.3 times more likely to be malignant, respectively, than grade 3 lesions.

Conclusion:

The radiological grading scheme used throughout Australia and parts of Europe is validated as a useful system of stratifying microcalcifications into groups with significantly different risks of malignancy. Biopsy assessment of appropriately selected microcalcifications is an effective method of detecting invasive breast cancer and DCIS, particularly of non-low-grade subtypes.

HER2/neu protein expression and fine needle breast aspiration from Argentinean patients with non-palpable breast lesions

The objective of this pilot project was to investigate whether the breast fine needle aspiration (FNA) technique is a useful tool for determining the increased risk of breast cancer in patients with non-palpable breast lesions. FNA is a minimally invasive technique that isolates mammary epithelial cells from breast cells in the suspicious region. In this study, two FNA samples were collected from 12 patients. The level of HER2/neu expression at the mRNA level (in serum) was measured in each patient. As gene amplification is characteristic of cancer cells and may assist in diagnosis and prognostic assessment, it is crucial that gene amplification of HER2/neu in patients with non-palpable breast lesions is compared to breast biopsy results. In serum, the level of HER2/neu was determined by ELISA assay. Gene amplification was determined by PCR and confirmed by IHC employing monoclonal ERRB2 in the FNA sample. The results indicate that FNA has a good correlation with breast biopsy. FNA combined with mammographic imaging is a strong tool for determining favorable treatment options for patients.

Lesion size is a major determinant of the mammographic features of ductal carcinoma in situ: findings from the Sloane project

AIM

To assess the radiological features of calcific ductal carcinoma in situ (DCIS) in a large, multicentre dataset according to grade and size, and to investigate the possibility that DCIS has different mammographic features when small.

MATERIALS AND METHODS

The dataset consisted of all Sloane Project DCIS cases where calcification was present mammographically and histological grade and size were available. The radiology data form classifies calcific DCIS as casting/linear, granular/irregular, or punctate. The pathology dataset includes cytonuclear grade and microscopic tumour size. Correlations were sought between the radiological findings and DCIS grade and size. The significance of differences was assessed using the chi-square test and chi-square test for trend.

RESULTS

One thousand, seven hundred and eighty-three cases were included in the study. Of these, 1128, 485, and 170 had high, intermediate, and low-grade DCIS, respectively. Casting calcification was more frequently seen the higher the grade of DCIS, occurring in 58% of high grade, 38% of intermediate grade, and 26% of low-grade cases, respectively (p<0.001). Casting calcification was also increasingly common with increasing lesion size, irrespective of the histological grade (p<0.001). Thus casting calcifications in small (<10mm) high-grade DCIS lesions were seen with a similar frequency (50%) to those in moderate-sized (21-30 mm) intermediate-grade lesions (48%), and to those in large (>30 mm) low-grade lesions (46%).

CONCLUSION

Lesion size has a strong influence on the radiological features of calcific DCIS; small, high-grade lesions often show no casting calcifications, whereas casting calcifications are seen in nearly half of large, low-grade lesions. As small clusters of punctate or granular calcifications may represent high-grade DCIS, an aggressive clinical approach to the diagnosis of such lesions is recommended as the adequate treatment of high-grade DCIS will prevent the occurrence of potentially life-threatening high-grade invasive disease.

Positive predictive value of specific mammographic findings according to reader and patient variables

PURPOSE

To evaluate the risk of cancer (positive predictive value [PPV]) associated with specific findings (mass, calcifications, architectural distortion, asymmetry) in mammographic examinations with abnormal results, to determine the distribution of these findings in examinations in which the patients received a diagnosis of cancer and examinations in which the patients did not, and to analyze PPV variation according to radiologist and patient factors.

MATERIALS AND METHODS

HIPAA-compliant institutional review board approval was obtained. PPV of mammographic findings was evaluated in a prospective cohort of 10,262 women who underwent 10,641 screening or diagnostic mammographic examinations with abnormal results between January 1998 and December 2002 in the San Francisco Mammography Registry. The cohort was linked with the Surveillance Epidemiology and End Results program to determine cancer status among these women. PPVs were calculated for each finding and were stratified according to patient characteristics, cancer type, and radiologist reader.

RESULTS

Cases of breast cancer (n = 1552) were identified (invasive, n = 1287; ductal carcinoma in situ, n = 270); in five, both kinds of breast cancer were recorded. Overall, of the number of interpretations, masses were most frequently noted in 56%, followed by calcifications in 29%, asymmetry in 12%, and architectural distortion in 4%. Masses, calcifications, architectural distortion, and developing asymmetry demonstrated similar PPVs in screening examinations (9.7%, 12.7%, 10.2%, and 7.4%, respectively), whereas one-view-only and focal asymmetry demonstrated lower PPVs (3.6% and 3.7%, respectively) and were a frequent reason for an abnormal result (42%). Overall, one (5%) in 20 invasive cancers was identified with asymmetry, one (6%) in 16 invasive cancers was identified with architectural distortion, one (21%) in five invasive cancers was identified with calcifications, and two (68%) in three invasive cancers were identified with a mass.

CONCLUSION

Five percent of invasive cancers were identified with asymmetry, and asymmetry is more weakly associated with cancer in screening examinations than are mass, calcifications, and architectural distortion.

Revisión de la evidencia científica sobre la aplicación clínica de la mamografía digital

OBJECTIVE

To review the scientific evidence with respect to the use of digital mammography and compare it with analogical mammography in the clinical context.

MATERIAL AND METHOD

We searched Medline and EMbase for studies published between 1989 and 2005 that compared the results of digital and analogical mammography in the same group of patients or in two different groups of patients to evaluate their respective diagnostic accuracy (sensitivity, specificity, area under the ROC curve), recall rate, biopsy rate, and exposure to radiation. We reviewed and compared the different methodologies of the studies published.

RESULTS

Eight articles and eight presentations at congresses were found. No statistically significant differences were observed between digital and analogical mammography for the detection of breast cancer. Until the publication of the Oslo II (2004) and Digital Mammographic Imaging Screening Trial (2005) studies, the series presented were small and used a variety of methodologies. This made it impossible to appreciate small differences in diagnostic accuracy between the two techniques and to group the, sometimes, contradictory results. Furthermore, these first series did not include follow-up.

CONCLUSION

There are no statistically significant differences between the two techniques for diagnostic accuracy, except in women with dense or heterogeneously dense breasts, in those under 50 years of age, and in peri- or pre-menopausal women, in which cases digital mammography is significantly better. These data should be confirmed in longer term studies to enable the effects on the breast cancer mortality rate to be specifically evaluated. Cost-effectiveness studies are important when considering changing techniques.

Incidental PET/CT Detection of Breast Cancer in a Patient with Negative Mammogram and Breast Sonogram

We present the case of a 57-year-old woman with known Hodgkins lymphoma who presented with PET/CT findings of a breast mass and diseased axillary lymph node despite negative results from a recent routine mammogram and ultrasound. Needle biopsy of the mass and lymph node confirmed a diagnosis of infiltrating ductal carcinoma of the breast with nodal metastases.

Relationship between prognostic factors of breast cancer and 99mTc-sestamibi uptake in patients who underwent scintimammography: Multivariate analysis of causes of false-negative results

The complementary role of sestamibi scintimammography (SSM) in patients with breast cancer (BC) is well established. The aim of this study was to establish whether a relationship exists between sestamibi uptake, evaluated as a tumour-to-background ratio (TBR), and the main prognostic factors of BC. SSM with the measurement of TBR was performed preoperatively in 102 women (median age 57 years, range 32-81 years) who underwent curative surgery for primary BC. Final pathology showed 4 (3.9%) with pT1a, 17 (16.7%) with pT1b, 44 (43.1%) with pT1c and 37 (36.3%) with pT2 breast carcinomas. The overall sensitivity of SSM was 80.4%. An ANOVA showed significant (P<0.01) differences between the TBR of patients with G1 vs. G3 tumours, and between the TBR of those with G2 vs. G3 breast carcinomas. Moreover, there was a difference (P=0.021) between the TBR of patients (n=12, 11.8%) with CEA serum levels >10 ng/ml (2.031+/-0.420), and those with normal (n=90, 88.2%) CEA values (1.713+/-0.446), whilst no difference (P=NS) was found between patients (n=27, 26.5%) with CA 15-3 >30 U/ml (1.893+/-0.401) and those with normal (n=75, 73.5%) CA 15-3 values (1.699+/-0.462). There was a mild inverse correlation between TBR and both the oestrogen (R=0.25, P=0.011) and the progesterone receptor (R=0.23, P=0.02) rate. The logistic regression analysis showed that only size and CA 15-3 serum levels represent true independent parameters, but the function was able to predict only 11 out of 21 (52.4%) patients with false-negative SSM. TBR is independent of age and mainly correlates with the size of the tumour. There are no reliable preoperative prognostic factors that are really useful for improving SSM sensitivity in patients with small breast carcinomas.

[Predictive factors for malignancy in breast microcalcifications without associated lesions]

INTRODUCTION

Screening mammography allows the early detection and treatment of nonpalpable carcinomas. Microcalcifications are highly important for the detection of many of these malignancies but are also present in benign breast disease. In the present study we analyzed the radiologic and clinical factors associated with malignancy.

MATERIAL AND METHODS

We retrospectively reviewed 133 patients who underwent open biopsy after a mammographic finding of microcalcifications without an associated lesion. Clinical and radiologic characteristics were correlated with histologic findings.

RESULTS

A total of 28.6% of the lesions analyzed were malignant. Of these, 65.8% were ductal carcinoma in situ. Among invasive carcinomas, 23.1% presented lymph node metastasis. No clinical criterion was significant for malignancy. On univariate analysis six radiologic criteria were significant: morphologic type (Le Gal's classification), irregularity of size, irregularity of density, number of microcalcifications per cluster, diameter of the lesion, and the presence of more than one cluster. On multivariate analysis the factors with independent predictive value were: irregularity of density, > or = 10 microcalcifications per cluster, the presence of more than one cluster, and diameter of the cluster > or = 10 mm.

CONCLUSIONS

Although none of the clinical factors analyzed was predictive for malignancy, the radiological characteristics of microcalcifications were determining factors in the indication for biopsy.

Digital Mammography: Current Capabilities and Obstacles

Digital mammography represents an exciting new technology for breast imaging and possibly breast screening. The decoupling of functional components in digital mammography translates into potential operational efficiencies compared with screen-film mammography (SFM). Digital mammography is a platform for advanced applications not possible with traditional SFM. However, for digital mammography to replace SFM in daily clinical practice, operational and clinical hurdles will have to be overcome.

[Architectural distortion and diagnostic difficulties]

Identification of architectural distortion requires a good practice of mammography. Prevalence is estimated at 6% of detected abnormalities in screening programs. Under this denomination are gathered focal architectural distortion with predictive positive value (PPV) of 10% and stellate images without central densification, which are more suspicious (PPV 50%). In order to establish a diagnosis, false images must be eliminated by other views. Minimal architectural distortion have to be investigated by other techniques (sonography, MRI percutaneous biopsy) in order to define the best strategy for further management. Stellate images suggestive of radial scars must be surgically removed. The relationships between radial scars and tubular carcinoma are discussed. A particular attention is required for post traumatic or post surgical scars if it exist a high risk of local recurrence or controlateral carcinoma specially after conservative or oncoplastic surgery.

Stellate images: anatomic and radiologic correlations

The stellate images are the most well-known and most typical finding in the diagnosis of breast cancer. Its positive predictive value is very high. However, in some cases, the stellate images can correspond to benign lesions. Stellate images require high quality mammograms, precise analysis, and as always in senology, confirmation by clinical examination, ultrasound if necessary, and in the case of palpable lesions, cytology. In this work, we will study malignant and benign stellate images mammographic-pathologic correlation as well as the importance of stellate images in the detection of non-palpable lesions. The typical stellate finding is correlated with the phenomena of fibrosis and elastosis and it is impossible to distinguish benign spicules from malignant spicules on mammography. We will present guidelines in the face of stellate image. Stellate images are for the most part suggestive of malignant lesions, and their discovery should lead to suspicion of cancer until the contrary is proven.

Positive predictive value of BI-RADS categorization in an Asian population

The Breast Imaging Reporting And Data System (BI-RADS) categorization of mammograms is useful in estimating the risk of malignancy, thereby guiding management decisions. However, in Asian women, in whom breast density is increased, the sensitivity of mammography is correspondingly lower. We sought to determine the positive predictive value of BI-RADS categorization for malignancy in our Asian population and, hence, its value in helping us to choose between the various modalities for breast biopsy. We retrospectively reviewed all patients with occult breast lesions detected on mammography or ultrasound who underwent needle-localization open breast biopsy (NLOB) in our institution over a 6-year period. There were 470 biopsies in 427 patients; 16% of lesions were malignant. The positive predictive value of BI-RADS 4 and 5 lesions for cancer was 0.27 and 0.84, respectively. While most BI-RADS 5 mass lesions were invasive cancers, the majority of calcifications in this category were in situ carcinomas. We conclude that BI-RADS remains useful in aiding decision-making for biopsy in our Asian population. Based on positive predictive values, we recommend percutaneous breast biopsy for initial evaluation of lesions categorized as BI-RADS 4 or less. For BI-RADS 5 lesions with microcalcifications, open surgical biopsy as a diagnostic and therapeutic procedure may be more appropriate. In the case of a BI-RADS 5 lesion associated with a mass, initial percutaneous biopsy may be useful for diagnosis, followed by a planned single-stage surgical procedure as necessary.

[Mammographic stable lesions and carcinomas]

Stable breast carcinomas at mammography are infrequent and typically correspond to low-grade non-invasive neoplasms. Diagnosis may be delayed by several months to a few years. This time delay to diagnosis may be reduced by using optimal mammographic technique and careful image interpretation. These lesions frequently are misclassified as BIRADS class III lesions. Comparison with prior mammograms is mandatory for accurate diagnosis of these lesions.

AAPM/RSNA Physics Tutorial for Residents

Recent advances in digital detector technology have paved the way to full-field digital mammography (FFDM) systems. The performance of these systems has evolved to the point where replacement of screen-film mammography (SFM) systems is becoming realistic. Despite some commonality between the two techniques, there are fundamental differences in how images are recorded, displayed, and stored. These differences necessitate an understanding of the principles of detection and the characteristics of digital images. Several approaches have been taken in the development of FFDM systems: (a) slot scanning with a scintillator and a charge-coupled device (CCD) array, (b) a flat-panel scintillator and an amorphous silicon diode array, (c) a flat-panel amorphous selenium array, (d) a tiled scintillator with fiberoptic tapers and a CCD array, and (e) photostimulable phosphor plates (computed radiography). Although the initial cost of an FFDM system is high compared with that of an SFM system, digital mammography has inherent advantages, such as wide dynamic range, reduction in recall rates, potential for reduction in radiation dose, increased patient throughput, postprocessing capability, and digital acquisition. These advantages and the rapidly occurring technologic developments will help establish FFDM as a mainstay of breast evaluation.

Is Stereotactic Large-Core Needle Biopsy Beneficial Prior to Surgical Treatment in BI-RADS 5 Lesions?

INTRODUCTION

Due to screening mammography, more nonpalpable mammographic lesions warrant histological evaluation. Stereotactic large-core needle biopsy (SLCNB) has been shown to be as effective in diagnosing these lesions as diagnostic surgical excision, and has become the preferred diagnostic procedure for most mammographic lesions. Since radiologically malignant BI-RADS 5 lesions are almost always carcinoma, some centers advocate prompt diagnostic surgical excision for these lesions instead of SLCNB. For some patients this diagnostic surgical intervention may serve as definitive treatment. We set out to find a subgroup of mammographic BI-RADS 5 lesions for which surgical biopsy might be preferable.

METHODS

Of 1644 consecutive nonpalpable lesions referred for SLCNB between April 1997 and May 2002, 238 were classified as BI-RADS 5. We assessed the number of carcinomas and the surgical interventions performed. Outcomes were compared between various types of mammographic lesions: density with calcifications, density without calcifications, and calcifications only. Different theoretical strategies for diagnostic work-up of BI-RADS 5 lesions were explored.

RESULTS

Carcinoma was found in 229/238 lesions (96%). Most mammographic densities were invasive cancer (97%), while calcifications only showed the highest risk for DCIS (51%). In our study (current practice) all lesions were scheduled to first undergo SLCNB. A scenario was proposed where all lesions with only a density would be scheduled directly for sentinel node biopsy (SNB) and tumour excision (n = 154; 65%), while other lesions would still be scheduled for SLCNB. When we compared this scenario to current practice, four out of 238 patients (< 2%) would be 'overtreated' with SNB.

CONCLUSIONS

Our findings confirm a high predictive value of malignancy for BI-RADS 5 lesions (96%). Surgical excision is therefore imperative for all BI-RADS 5 lesions, irrespective of SLCNB results. For BI-RADS 5 lesions presenting as mammographic densities only, we propose to consider surgical excision with SNB to be the first diagnostic and therapeutic procedure. SLCNB is preferred in all other cases.

Breast imaging in the new era

In the last decade,there have been huge advances in the field of breast imaging.Full field digital mammography systems optimise lesion to background contrast with resultant improvement in the sensitivity of the technique for cancer detection, facilitated by computer-aided detection.Though mammography remains the only established modality for population-based screening, preliminary results from several large studies indicate that magnetic resonance imaging(MRI) has a role in high-risk patients.On the other hand, advances in ultrasound, MRI and nuclear medicine have the potential to greatly improve the specificity of breast imaging with regard to cancer detection and lesion characterisation.A number of new and experimental techniques are being developed which may have great impact in this area and these will be discussed. Though MRI now has an established place in the diagnosis of breast cancer, it is becoming clear that it can directly affect surgical and medical management by enabling assessment of response to chemotherapy and endocrine therapy, and facilitating choice of the most appropriate surgery.Just as the role of MRI has evolved,so too the place of nuclear medicine, particularly positron emission tomography and radio-immunoscintigraphy should become clearer in the next few years.

Digital mammography: a review of technical development and clinical applications

For detecting and diagnosing breast cancer at its earliest stage, mammography is the most sensitive technique currently available and is therefore the method of choice. Screen-film mammography has been used successfully as a screening test for breast cancer for > 2 decades. However, conventional mammography has substantial limitations and, therefore, digital mammography systems have been developed to improve image quality and overcome the limitations of screen-film technique limitations. Herein we discuss the differences between screen-film and digital mammography systems and the processes related to digital mammography that differ from conventional mammography, including detector technology, digital image formation, image processing, image display, and image archival. Finally, we review the results from currently available clinical trials regarding the performance of digital mammography and discuss clinical implications such as cost-effectiveness.

Radiology review of the UKCCCR Breast Screening Frequency Trial: potential improvements in sensitivity and lead time of radiological signs

AIM

To review all previous mammograms of breast cancer cases diagnosed during a randomized trial comparing 3 yearly to annual mammographic screening with a view to identifying and quantifying cases that might potentially have been diagnosed earlier.

METHODS

Mammograms of 602 breast cancer cases (399 screen-detected and 203 interval cases) were reviewed in chronological order and suspicious radiological features noted for each mammogram, up to and including the diagnostic mammogram.

RESULTS

Of the 602 cases, 79 (13%) had features at diagnosis that were visible on previous mammograms, suggesting a sensitivity of interpretation of 87%. A similar proportion of screen-detected (14%) and interval cancers (11%) had signs at diagnosis that were visible on previous mammograms. The potential for improvement was particularly noted for asymmetric density (sensitivity = 77%, average time visible before diagnosis 14 months) and parenchymal deformity/stellate lesion (sensitivity = 81%, average time visible before diagnosis 12 months).

CONCLUSION

The highest sensitivity was observed for comedo-type microcalcifications (sensitivity = 97%, average time visible before diagnosis 5 months). By improvements in sensitivity to asymmetric density and parenchymal deformity/stellate lesion, 4% of tumours could have their time of diagnosis advanced substantially.

Positive predictive value of 99mTc sestamibi scintimammography in patients with non-palpable, mammographically detected, suspicious, breast lesions

The purpose of this study was to analyse whether the use of Tc sestamibi scintimammography improves the positive predictive value of X-ray mammography. A series of 73 women (median age 51 years, range 35-79 years) with non-palpable, mammographically suspicious, breast lesions was reviewed. There were 41 (56.2%) pre-menopausal, and 32 (43.8%) post-menopausal women. All patients underwent sestamibi scintimammography prior to open breast biopsy. Definitive histology showed breast cancer (pT1a=1 (1.9%), pT1b=47 (90.4%), pT1c=4 (7.7%)) in 52 (71.2%) patients, and benign breast lesions in 21 (28.8%). Patients with cancer were significantly older (P <0.01), while the greatest dimension (size) of the excised lesion did not differ (8.47+/-1.51 vs 8.30+/-1.53 mm; P =0.66) between the two groups. Overall, the positive predictive values of mammography and sestamibi scintimammography were 71.2% and 95.7%, respectively (P =0.004). Patients with false positive mammography were significantly younger than those in whom cancer was diagnosed correctly (45.35+/-7.56 vs 53.96+/-10.60 years; P =0.001), while age did not affect the sensitivity of sestamibi scintimammography, which reached 100% in patients with breast lesions > or =8 mm in size. In this subgroup the positive predictive value of mammography, sestamibi scintimammography, and mammography+sestamibi scintimammography together were 63.4%, 95.1% (P =0.001), and 97.6%, respectively, and the majority of the patients with benign lesions (13 of 15 (86.7%)) could have avoided biopsy. It is concluded that the use of Tc sestamibi scintimammography in conjunction with mammography may potentially reduce unnecessary surgical procedures, and should be performed in all patients with mammographically suspicious breast lesions of 8 mm or greater in size.

New modalities in breast imaging: digital mammography, positron emission tomography, and sestamibi scintimammography

Digital mammography, PET, and sestamibi scintimammography are three new modalities in breast imaging. DM has advantages over film-screen mammography in image storage, retrieval, and processing and may lower the recall rate. Computer-aided detection may increase the sensitivity of mammographic screening without a substantial reduction in specificity. Whereas PET and sestambi scintimammography are not useful in breast cancer screening, PET may play a role in detecting nodal metastases and monitoring treatment response, and sestamibi scintimammography in selected cases may serve as an adjunct to conventional imaging. The cost-effectiveness of these new modalities remains to be evaluated, but all have the potential to significantly advance the diagnosis and management of women with breast cancer.

Nonpalpable breast cancer: mammographic appearance as predictor of histologic type

PURPOSE

To investigate the association between mammographic appearance and histologic diagnosis of nonpalpable breast cancers.

MATERIALS AND METHODS

Mammographic characteristics of 317 consecutive clinically nonpalpable breast cancers in patients treated with breast-conserving surgery were reviewed. Malignant lesions were categorized as spiculated masses, other lesions, calcifications, and combined findings. Calcifications were characterized as amorphous, pleomorphic, or fine linear and branching. Logistic regression was used for the evaluation. Odds ratios (ORs) represent the magnitude of the association between a histologic diagnosis and a mammographic finding.

RESULTS

Spiculated mass without calcifications (n = 150) and calcifications alone (n = 79) accounted for three of four cancers. A spiculated mass without calcifications was strongly associated with invasive cancers (OR = 12). Calcifications alone were strongly associated with ductal carcinoma in situ (DCIS) (OR = 19). In a decreasing order, the following invasive cancers were each associated with spiculated lesions without calcifications: ductal carcinoma grade 1 (OR = 28), ductal carcinoma grade 2 (OR = 17), lobular carcinoma (OR = 11), and ductal carcinoma grade 3 (OR = 4.6). Fine linear and branching calcifications alone were associated with not only DCIS nuclear grades 3 (OR = 17) and 2 (OR = 9.7) but also with invasive ductal carcinoma grade 3 (OR = 13).

CONCLUSION

Mammographic appearance can be a predictor of histologic diagnosis in three of four nonpalpable breast cancers.

New mammographic stromal deformity: what is the significance of this finding on screening mammograms?

Current practice within the NHS Breast Screening Programme recommends surgical excision of screen detected areas of stromal deformity as differentiating carcinomas from radial scars and excluding in situ malignancy in association with radial scars is unreliable. We retrospectively reviewed all cases recalled for assessment over a 4 year period, identified to have an area of persistent stromal deformity not associated with surgical scarring and without an associated mammographic mass. Thirty women were prevalent (first) round screens--17 cases proved to be malignant and 13 benign. The latter group included three cases of atypical ductal hyperplasia. Nineteen women were incident (subsequent) round screens--all 19 cases proved to be malignant. This study supports the practice of surgically removing all areas of stromal deformity, particularly new areas of stromal deformity detected in the incident round, as in this group the likelihood of malignancy is extremely high.

Fine-Needle Aspiration Biopsy of Nonpalpable Breast Lesions in a Multicenter Clinical Trial: Results from the Radiologic Diagnostic Oncology Group V

PURPOSE

To determine the diagnostic accuracy of ultrasonographically (US) and stereotactically guided fine-needle aspiration biopsy (FNAB) in the diagnosis of nonpalpable breast lesions.

MATERIALS AND METHODS

At 18 institutions, 442 women who underwent 22-25-gauge imaging-guided FNAB were enrolled. Definitive surgical, core-needle biopsy, and/or follow-up information was available for 423 (95.7%) of these women. The reference standard was established from additional clinical and imaging information for an additional six (1.4%) women who did not undergo further histopathologic evaluation. The FNAB protocol was standardized at all institutions, and all specimens were reread by one of two expert cytopathologists.

RESULTS

When insufficient samples were included in the analysis and classified as positive, the sensitivity and specificity of FNAB were 85%-88% and 55.6%-90.5%, respectively; accuracy ranged from 62.2% to 89.2%. The diagnostic accuracy of FNAB was significantly better for detection of masses than for detection of calcifications (67.3% vs. 53.8%, P =.006) and with US guidance than with stereotactic guidance (77.2% vs. 58.9%; P =.002).

CONCLUSION

FNAB of nonpalpable breast lesions has limited value given the high insufficient sample rate and greater diagnostic accuracy of other interventions, including core-needle biopsy and needle-localized open surgical biopsy.

Changes in Benign to Malignant Ratio of Surgically Treated Breast Diseases in a District Hospital

The benign to malignant ratio (BMR) of open surgical biopsies is often used to monitor the efficacy of diagnostic workup of breast lesions. Avoiding the unnecessary removal of benign lesions is of recognized importance. Histopathology archives of the Department of Pathology of the Bács-Kiskun County Hospital were retrieved for breast lesions and the BMR of surgical specimens was determined for each year between the period of 1965-1996. The introduction of mammography and especially fine-needle aspiration cytology was paralleled by a reduction in the benign to malignant ratio from 1.7 to 0.7. Only the introduction of breast aspiration cytology seemed to have a significant effect on the BMR, but the more adequate diagnostic approach to breast lesions (mostly palpable in their nature) was in part masqueraded by the late shift in attitude of both surgeons and patients towards breast lumps. This is why the BMR can give a basic information on preoperative diagnostic workup of breast lesions, but in itself it is not able to monitor them.