Long-term Surveillance of Ductal Carcinoma in Situ Detected with Screening Mammography versus US: Factors Associated with Second Breast Cancer

Evolving Treatment Paradigms for Low-Risk Ductal Carcinoma In Situ: Imaging Needs

Ductal carcinoma in situ (DCIS) is a nonobligate precursor to invasive cancer that classically presents as asymptomatic calcifications on screening mammography. The increase in DCIS diagnoses with organized screening programs has raised concerns about overdiagnosis, while a patientcentric push for more personalized care has increased awareness about DCIS overtreatment. The standard of care for most new DCIS diagnoses is surgical excision, but nonsurgical management via active monitoring is gaining attention, and multiple clinical trials are ongoing. Imaging, along with demographic and pathologic information, is a critical component of active monitoring efforts. Commonly used imaging modalities including mammography, ultrasound, and MRI, as well as newer modalities such as contrast-enhanced mammography and dedicated breast PET, can provide prognostic information to risk stratify patients for DCIS active monitoring eligibility. Furthermore, radiologists will be responsible for closely surveilling patients on active monitoring and identifying if invasive progression occurs. Active monitoring is a paradigm shift for DCIS care, but the success or failure will rely heavily on the interpretations and guidance of radiologists.

Differentiation Between Phyllodes Tumors and Fibroadenomas of Breast Using Mammography-based Machine Learning Methods: A Preliminary Study

OBJECTIVE

To investigate the diagnostic performance of a mammography-based radiomics model for distinguishing phyllodes tumors (PTs) from fibroadenomas (FAs) of the breast.

MATERIALS AND METHODS

A total of 156 patients were retrospectively included (75 with PTs, 81 with FAs) and divided into training and validation groups at a ratio of 7:3. Radiomics features were extracted from craniocaudal and mediolateral oblique images. The least absolute shrinkage and selection operator (LASSO) algorithm and principal component analysis (PCA) were performed to select features. Three machine learning classifiers, including logistic regression (LR), K-nearest neighbor classifier (KNN) and support vector machine (SVM), were implemented in the radiomics model, imaging model and combined model. Receiver operating characteristic curves, area under the curve (AUC), sensitivity and specificity were computed.

RESULTS

Among 1084 features, the LASSO algorithm selected 17 features, and PCA further selected 6 features. Three machine learning classifiers yielded the same AUC of 0.935 in the validation group for the radiomics model. In the imaging model, KNN yielded the highest accuracy rate of 89.4% and AUC of 0.947 in the validation set. For the combined model, the SVM classifier reached the highest AUC of 0.918 with an accuracy rate of 86.2%, sensitivity of 83.9%, and specificity of 89.4% in the training group. In the validation group, LR yielded the highest AUC of 0.973. The combined model had a relatively higher AUC than the radiomics model or imaging model, especially in the validation group.

CONCLUSIONS

Mammography-based radiomics features demonstrate good diagnostic performance for discriminating PTs from FAs.

The diagnostic value of contrast-enhanced ultrasonography in breast ductal abnormalities

BACKGROUND

Ductal lesions are an important, often overlooked, and poorly understood issue in breast imaging, which have a risk of underlying malignancy ranging from 5 to 23%. Ultrasonography (US), which has largely replaced galactography or ductography, has become an important imaging method to assess patients with ductal lesions. However, it is difficult to distinguish benign from malignant ductal abnormalities only by ultrasonography, most of which are recommended to be at least in subcategory 4A; these require biopsy according to the ACR BI-RADS®atlas 5th Edition-breast ultrasound. Contrast-enhanced ultrasound (CEUS) has been shown to be valuable for differentiating benign from malignant tumors, but its value is unclear in breast ductal lesions. Therefore, the purposes of this study were to explore the characteristics of malignant ductal abnormalities on US and CEUS imaging and the diagnostic value of CEUS in breast ductal abnormalities.

METHODS

Overall, 82 patients with 82 suspicious ductal lesions were recruited for this prospective study. They were divided into benign and malignant groups according to the pathological results. Morphologic features and quantitative parameters of US and CEUS were analyzed by comparison and multivariate logistic regression to determine the independent risk factors. The diagnostic performance was assessed by receiver operating characteristic (ROC) curve analysis.

RESULTS

Shape, margin, inner echo, size, microcalcification and blood flow classification on US, wash-in time, enhancement intensity, enhancement mode, enhancement scope, blood perfusion defects, peripheral high enhancement and boundary on CEUS were identified as features correlated with malignant ductal lesions. However, multivariate logistic regression showed that only microcalcification (OR = 8.96, P = 0.047) and enhancement scope (enlarged, OR = 27.42, P = 0.018) were independent risk factors for predicting malignant ductal lesions. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy and area under the ROC curve of microcalcifications combined with an enlarged enhancement scope were 0.895, 0.886, 0.872, 0.907, 0.890, and 0.92, respectively.

CONCLUSIONS

Microcalcification and enlarged enhancement scope are independent factors for predicting malignant ductal lesions. The combined diagnosis can greatly improve the diagnostic performance, indicating that CEUS can be useful in the differentiation of benign and malignant lesions to formulate more appropriate management for ductal lesions.

Factors influencing suboptimal pathologic margins and re-excision following breast conserving surgery for ductal carcinoma in-situ

INTRODUCTION

Re-excisions following breast conserving surgery (BCS) are common, occurring more frequently in ductal carcinoma in-situ (DCIS) than its' malignant counterpart. Although one quarter of patients with breast cancer will have DCIS, there is limited information available regarding factors predisposing to inadequate pathologic margins, and the need for re-excision.

METHODS

Retrospective review of patients treated for DCIS between the years 2010-2016 was conducted. Patients with DCIS undergoing BCS were identified and evaluated for demographic and pathologic factors associated with suboptimal pathologic margins and re-excision. Multivariate analysis with Wald Chi-Square testing was performed.

RESULTS

241 patients underwent BCS with suboptimal margins (SOM) in 51.7% (123/238), with 27.8% undergoing re-excision (67/241). Tumor size was the most influential variable, positively associated with SOM (OR = 10.25, CI: 5.50-19.13) and re-excision (OR = 6.36, CI: 3.92-10.31). Patient age was inversely associated with SOM (OR = 0.58, CI: 0.39-0.85) and subsequent re-excisions (OR = 0.56, CI: 0.36-0.86). Low tumour grade was associated with re-excision (OR = 1.31, CI: 0.63-2.71), while ER negative disease was associated with SOM (OR = 2.24, CI: 1.21-4.14).

DISCUSSION

Inadequate pathologic margins following BCS, and subsequent re-excision rates are common in patients with DCIS, and consistent with the literature. Tumour size is the dominant factor driving this occurrence, with patient age and tumour grade also impacting outcomes.

ACR Appropriateness Criteria® Imaging After Breast Surgery

Given that 20% to 40% of women who have percutaneous breast biopsy subsequently undergo breast surgery, knowledge of imaging women with a history of benign (including high-risk) disease or breast cancer is important. For women who had surgery for nonmalignant pathology, the surveillance recommendations are determined by their overall risk. Higher-than-average risk women with a history of benign surgery may require screening mammography starting at an earlier age before 40 and may benefit from screening MRI. For women with breast cancer who have undergone initial excision and have positive margins, imaging with diagnostic mammography or MRI can sometimes guide additional surgical planning. Women who have completed breast conservation therapy for cancer should get annual mammography and may benefit from the addition of MRI or ultrasound to their surveillance regimen. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Intraductal delivery of nanocarriers for ductal carcinoma in situ treatment: a strategy to enhance localized delivery

Ductal carcinoma in situ describes the most commonly occurring, noninvasive malignant breast disease, which could be the leading factor in invasive breast cancer. Despite remarkable advancements in treatment options, poor specificity, low bioavailability and dose-induced toxicity of chemotherapy are the main constraint. A unique characteristic of nanocarriers may overcome these problems. Moreover, the intraductal route of administration serves as an alternative approach. The direct nanodrug delivery into mammary ducts results in the accumulation of anticancer agents at targeted tissue for a prolonged period with high permeability, significantly decreasing the tumor size and improving the survival rate. This review focuses mainly on the intraductal delivery of nanocarriers in treating ductal carcinoma in situ, together with potential clinical translational research.

A Novel Nomogram for Predicting Prognosis and Tailoring Local Therapy Decision for Ductal Carcinoma In Situ after Breast Conserving Surgery

Purpose: We sought to explore the role of nomogram-combined biomarkers, mammographic microcalcification and inflammatory hematologic markers in guiding local therapy decisions in ductal carcinoma in situ (DCIS) subgroups with different ipsilateral breast tumour recurrence (IBTR) risk. Methods: Between January 2009 and December 2018, consecutive patients with DCIS and breast conserving surgery (BCS) were enrolled and randomly assigned to a training cohort (n = 181) and internally validation cohort (n = 78). Multivariate analyses were performed to identify predictors of IBTR. Model performance was evaluated by the concordance index (C-index) and calibration plot. The time-to-event curves were calculated by the Kaplan−Meier methods and compared by the log-rank test. Results: In total, 259 patients were enrolled and 182 of them received whole breast irradiation (WBI). After a median follow-up of 51.02 months, 23 IBTR events occurred in the whole cohort. By multivariate analyses of training cohort, presence of microinvasion, Ki67 index >14%, mammographic-clustered fine linear microcalcifications and neutrophil/lymphocyte ratio before BCS (preop-NLR), >1.1 remained independent risk factors of IBTR to develop a nomogram. The C-indexes of the nomogram were 0.87 and 0.86 in the training and internal validation set, respectively. Calibration plots illustrated good agreement between the predictions and actual observations for 5-year IBTR. Cut-off values of nomogram point were identified as 53 and 115 points, which divided all patients into low-, intermediate- and high-risk groups. Significant differences in IBTR existed between low-, intermediate- and high-risk subgroups (p < 0.01). For the whole cohort and ER-positive tumours, the benefit of WBI was found only in the intermediate-risk subgroup, but not in those with low or high risk. Fourteen out of 23 IBTRs occurred outside the original quadrant and all occurred in the high-risk group. Conclusions: The novel nomogram demonstrated potential to separate the risk of IBTR and locations of IBTR. For the whole cohort and ER-positive tumours, the benefit of WBI was restricted to an intermediate-risk subgroup.

US, Mammography, and Histopathologic Evaluation to Identify Low Nuclear Grade Ductal Carcinoma in Situ

Background Low nuclear grade ductal carcinoma in situ (DCIS) identified at biopsy can be upgraded to intermediate to high nuclear grade DCIS at surgery. Methods that confirm low nuclear grade are needed to consider nonsurgical approaches for these patients. Purpose To develop a preoperative model to identify low nuclear grade DCIS and to evaluate factors associated with low nuclear grade DCIS at biopsy that was not upgraded to intermediate to high nuclear grade DCIS at surgery. Materials and Methods In this retrospective study, 470 women (median age, 50 years; interquartile range, 44-58 years) with 477 pure DCIS lesions at surgical histopathologic evaluation were included (January 2010 to December 2015). Patients were divided into the training set (n = 330) or validation set (n = 147) to develop a preoperative model to identify low nuclear grade DCIS. Features at US (mass, nonmass) and at mammography (morphologic characteristics, distribution of microcalcification) were reviewed. The upgrade rate of low nuclear grade DCIS was calculated, and multivariable regression was used to evaluate factors for associations with low nuclear grade DCIS that was not upgraded later. Results A preoperative model that included lesions manifesting as a mass at US without microcalcification and no comedonecrosis at biopsy was used to identify low nuclear grade DCIS, with a high area under the receiver operating characteristic curve of 0.97 (95% CI: 0.94, 1.00) in the validation set. The upgrade rate of low nuclear grade DCIS at biopsy was 38.8% (50 of 129). Ki-67 positivity (odds ratio, 0.04; 95% CI: 0.0003, 0.43; P = .005) was inversely associated with constant low nuclear grade DCIS. Conclusion The upgrade rate of low nuclear grade ductal carcinoma in situ (DCIS) at biopsy to intermediate to high nuclear grade DCIS at surgery occurred in more than a third of patients; low nuclear grade DCIS at final histopathologic evaluation could be identified if the mass was viewed at US without microcalcifications and had no comedonecrosis at histopathologic evaluation of biopsy. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Rahbar in this issue.

Chronological Trends of Breast Ductal Carcinoma In Situ: Clinical, Radiologic, and Pathologic Perspectives

BACKGROUND

Because no prior studies have evaluated the chronological trends of ductal carcinoma in situ (DCIS) despite the increasing number of surgeries performed for DCIS, this study analyzed how the clinical, radiologic, and pathologic characteristics of DCIS changed during a 10-year period.

METHODS

Of 7123 patients who underwent primary breast cancer surgery at a single institution from 2006 to 2015, 792 patients with pure DCIS were included in this study. The chronological trends of age, symptoms, method for detecting either mammography or ultrasonography, tumor size, nuclear grade, comedonecrosis, and molecular markers were calculated using Poisson regression for all patients and asymptomatic patients.

RESULTS

During 10 years, DCIS surgery rates significantly increased (p < 0.001). Despite the high percentage of DCIS detected on mammography, the detection rate for DCIS by mammography significantly decreased (97.3% in 2006 to 67.6% in 2015; p = 0.025), whereas the detection rate by ultrasound significantly increased (2.7% to 31.0%; p < 0.001). Conservation surgery rates (odds ratio [OR], 1.058), low-to-intermediate nuclear grade rates (OR, 1.069), and the absence of comedonecrosis (OR, 1.104) significantly increased over time (all p < 0.05). Estrogen receptor (ER) negativity (OR, 0.935) and human epidermal growth factor receptor 2 (HER2) positivity rates (OR, 0.953) significantly decreased (all p < 0.05). The same trends were observed for the 613 asymptomatic patients.

CONCLUSION

The rate of DCIS detected on ultrasound only significantly increased during 10 years. Low-to-intermediate nuclear grade rates significantly increased, whereas ER negativity and HER2 positivity rates significantly decreased during the same period. These findings suggest that DCIS detected on screening ultrasound is less aggressive than DCIS detected on mammography.