Accuracy of Breast Magnetic Resonance Imaging Compared to Mammography in the Preoperative Detection and Measurement of Pure Ductal Carcinoma In Situ: A Retrospective Analysis

Clinical and Imaging Characteristics of Contrast-enhanced Mammography and MRI to Distinguish Microinvasive Carcinoma from Ductal Carcinoma In situ

RATIONALE AND OBJECTIVES

The prognosis of ductal carcinoma in situ with microinvasion (DCISM) is more similar to that of small invasive ductal carcinoma (IDC) than to pure ductal carcinoma in situ (DCIS). It is particularly important to accurately distinguish between DCISM and DCIS. The present study aims to compare the clinical and imaging characteristics of contrast-enhanced mammography (CEM) and magnetic resonance imaging (MRI) between DCISM and pure DCIS, and to identify predictive factors of microinvasive carcinoma, which may contribute to a comprehensive understanding of DCISM in clinical diagnosis and support surveillance strategies, such as surgery, radiation, and other treatment decisions.

MATERIALS AND METHODS

Forty-seven female patients diagnosed with DCIS were included in the study from May 2019 to August 2023. Patients were further divided into two groups based on pathological diagnosis: DCIS and DCISM. Clinical and imaging characteristics of these two groups were analyzed statistically. The independent clinical risk factors were selected using multivariate logistic regression and used to establish the logistic model [Logit(P)]. The diagnostic performance of independent predictors was assessed and compared using receiver operating characteristic (ROC) analysis and DeLong's test.

RESULTS

In CEM, the maximum cross-sectional area (CSAmax), the percentage signal difference between the enhancing lesion and background in the craniocaudal and mediolateral oblique projection (%RSCC, and %RSMLO) were found to be significantly higher for DCISM compared to DCIS (p = 0.001; p < 0.001; p = 0.008). Additionally, there were noticeable statistical differences in the patterns of enhancement morphological distribution (EMD) and internal enhancement pattern (IEP) between DCIS and DCISM (p = 0.047; p = 0.008). In MRI, only CSAmax (p = 0.012) and IEP (p = 0.020) showed significant statistical differences. The multivariate regression analysis suggested that CSAmax (in CEM or MR) and %RSCC were independent predictors of DCISM (all p < 0.05). The area under the curve (AUC) of CSAmax (CEM), %RSCC (CEM), Logit(P) (CEM), and CSAmax (MR) were 0.764, 0.795, 0.842, and 0.739, respectively. There were no significant differences in DeLong's test for these values (all p > 0.10). DCISM was significantly associated with high nuclear grade, comedo type, high axillary lymph node (ALN) metastasis, and high Ki-67 positivity compared to DCIS (all p < 0.05).

CONCLUSION

The tumor size (CSAmax), enhancement index (%RS), and internal enhancement pattern (IEP) were highly indicative of DCISM. DCISM tends to express more aggressive pathological features, such as high nuclear grade, comedo-type necrosis, ALN metastasis, and Ki-67 overexpression. As with MRI, CEM has the capability to help predict when DCISM is accompanying DCIS.

The Role of MRI in Breast Cancer and Breast Conservation Therapy

Contrast-enhanced breast MRI has an established role in aiding in the detection, evaluation, and management of breast cancer. This article discusses MRI sequences, the clinical utility of MRI, and how MRI has been evaluated for use in breast radiotherapy treatment planning. We highlight the contribution of MRI in the decision-making regarding selecting appropriate candidates for breast conservation therapy and review the emerging role of MRI-guided breast radiotherapy.

Role of contrast-enhanced mammography in the preoperative detection of ductal carcinoma in situ of the breasts: a comparison with low-energy image and magnetic resonance imaging

OBJECTIVES

To compare contrast-enhanced mammography (CEM) with low-energy image (LEI) alone and with magnetic resonance imaging (MRI) in the preoperative diagnosis of ductal carcinoma in situ (DCIS).

METHODS

In this single-center retrospective study, we reviewed 98 pure DCIS lesions in 96 patients who underwent CEM and MRI within 2 weeks preoperatively. The diagnostic performances of each imaging modality, lesion morphology, and extent were evaluated.

RESULTS

The sensitivity of CEM to DCIS was similar to that of MRI (92.9% vs. 93.9%, p = 0.77) and was significantly higher than that of LEI alone (76.5%, p = 0.002). The sensitivity of CEM to calcified DCIS (92.4%) was not significantly different from LEI alone (92.4%) and from MRI (93.9%, p = 1.00). However, CEM contributed to the simultaneous comparison of calcifications with enhancements. CEM had considerably higher sensitivity compared with LEI alone (93.8% vs. 43.8%, p < 0.001) and performed similarly to MRI (93.8%, p = 1.00) for noncalcified DCIS. All DCIS lesions were enhanced in MRI, whereas 94.9% (93/98) were enhanced in CEM. Non-mass enhancement was the most common presentation (CEM 63.4% and MRI 66.3%). The difference between the lesion size on each imaging modality and the histopathological size was smallest in MRI, followed by CEM, and largest in LEI.

CONCLUSION

CEM was more sensitive than LEI alone and comparable to MRI in DCIS diagnosis. The enhanced morphology of DCIS in CEM was consistent with that in MRI. CEM was superior to LEI alone in size measurement of DCIS.

CLINICAL RELEVANCE STATEMENT

This study investigated the value of CEM in the diagnosis and evaluation of DCIS, aiming to offer a reference for the selection of examination methods for DCIS and contribute to the early diagnosis and precise treatment of DCIS.

KEY POINTS

• DCIS is an important indication for breast surgery. Early and accurate diagnosis is crucial for DCIS treatment and prognosis. • CEM overcomes the deficiency of mammography in noncalcified DCIS diagnosis, exhibiting similar sensitivity to MRI; and CEM contributes to the comparison of calcification and enhancement of calcified DCIS, thereby outperforming MRI. • CEM is superior to LEI alone and slightly inferior to MRI in the size evaluation of DCIS.

Correlation of background parenchymal enhancement on breast MRI with breast cancer

AIM

To evaluate the prognostic value of background parenchymal enhancement (BPE) in breast magnetic resonance imaging (MRI) in women referred to radiological department as a high risk for breast cancer.

MATERIALS AND METHODS

A retrospective, cross-sectional study included 327 consecutive patients (mean age: 60 years, age range: 30-90 years) who underwent breast MRI and tissue biopsy between 2007 and 2016. All MRI images (T1, T2, and subtraction images) were evaluated visually. The relationship of BPE with patient age, fibroglandular tissue (FGT), Breast Imaging Reporting and Data System (BIRADS) categories, presence of breast cancer, and expression of human epidermal growth factor receptor 2 (HER2), progesterone receptor (PR), oestrogen receptor (ER), and Ki67 were analysed. Furthermore, all variables were correlated with pre- and postmenopausal status.

RESULTS

BPE of bilateral breast showed a weak correlation with FGT (right BPE: r=-0.14, p=0.004; left BPE: r=0.16, p=0.003), a weak negative correlation with patient age (right BPE: r=-0.14, p=0.007; left BPE: r=-0.15, p=0.006), and significant correlation with HER2 (right BPE, p=0.02), left BPE with HER2 was not significant. Among the correlations between BPE and BIRADS, only between right BPE and right BIRADS was significant (p=0.031). No clear evidence of an association between breast MRI BPE and breast cancer in premenopausal and postmenopausal status was observed, and no difference was found between the right and left breasts.

CONCLUSIONS

The results of the present study showed no significant correlations between BPE and breast cancer. In addition, there was no significant difference between the right and left breast. Hence, BPE of MRI may not be a reliable biomarker of breast cancer development.

The efficacy of abbreviated breast MRI protocols using 1.5 T MRI in the preoperative staging of newly diagnosed breast cancers

PURPOSE

To determine the efficacy of abbreviated breast magnetic resonance imaging (MRI) protocols using 1.5 T MRI in the preoperative staging of newly diagnosed breast cancers.

METHODS

Eighty patients who underwent 1.5 T MRI between August 2014 and January 2018 for the preoperative staging of breast cancer were evaluated retrospectively. Three separate abbreviated breast MRI protocols (AP) were created from a full protocol, and the images were evaluated independently by two radiologists. AP1 included axial fat-saturated T2 weighted and diffusion-weighted (DW) images, while subtracted axial fat-saturated T1 weighted images were obtained 2 min after contrast administration in AP2. Finally, AP2 and DW images were evaluated in AP3. Lesion location, number, and size, and presence of axillary lymphadenopathy were evaluated in each protocol. Pathological data (lesion quadrant, lesion size, and presence of axillary metastases) from the 80 patients were compared with the abbreviated protocols and full diagnostic protocol.

RESULTS

The best correlation with the full protocol for detecting the lesion quadrant, number of lesions, and presence of axillary lymphadenopathy was achieved with AP3 for both readers (κ = 0.954, 0.954 for the lesion quadrant, κ = 0.971, 0.910 for the number of lesions, and κ = 0.973, 0.865 for the axillary lymphadenopathy). The evaluation time in all abbreviated protocols was shorter than for the full protocol (p < 0.05). Comparing the abbreviated protocols with pathological data for both readers, the best correlation for detecting the lesion quadrant, number of lesions, and presence of axillary lymphadenopathy was achieved with AP3 (κ = 0.939, 0.954 for the lesion quadrant, κ = 0.941, 0.879 for the number of lesions, and κ = 0.842, 0.740 for axillary lymphadenopathy, respectively).

CONCLUSION

Abbreviated breast MRI protocols can provide sufficient diagnostic accuracy in the preoperative staging of breast cancer, with shorter imaging and evaluation times.

Identifying recurrences and metastasis after ductal carcinoma in situ (DCIS) of the breast

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive tumour that has the potential to progress to invasive ductal carcinoma (IDC). Thus, it represents a treatment dilemma: alone it does not present a risk to life, however, left untreated it may progress to a life-threatening condition. Current clinico-pathological features cannot accurately predict which patients with DCIS have invasive potential, and therefore clinicians are unable to quantify the risk of progression for an individual patient. This leads to many women being over-treated, while others may not receive sufficient treatment to prevent invasive recurrence. A better understanding of the molecular features of DCIS, both tumour-intrinsic and the microenvironment, could offer the ability to better predict which women need aggressive treatment, and which can avoid therapies carrying significant side-effects and such as radiotherapy. In this review, we summarise the current knowledge of DCIS, and consider future research directions.

The accuracy of magnetic resonance imaging in predicting the size of pure ductal carcinoma in situ: a systematic review and meta-analysis

Ductal carcinoma in situ (DCIS) is a putative precursor of invasive breast cancer and MRI is considered the most sensitive imaging technique for its detection. This study aims to evaluate the accuracy of MRI measuring the pure DCIS size, against pathology, to better understand the role of MRI in the management of this intraductal neoplasm.Potentially eligible studies in MEDLINE, Embase and Google Scholar, up to January 2021 were considered, and a systematic review and meta-analysis according to the published protocol (Prospero-CRD42021232228) was performed. Outcomes of mean differences and accuracy rates were analysed using IBM^® SPSS^® v26 and random-effect models in platform R v3.3.Twenty-two cross-sectional studies were selected and 15 proceeded to meta-analysis. MRI accurately predicted 55% of the tumours' sizes and, according to Bland-Altman plots, concordance between MRI and pathology was greater for smaller tumours. In the meta-analysis, difference of the means between MRI and pathology was 3.85 mm (CI 95% [-0.92;8.60]) with considerable heterogeneity (I2 = 96.7%). Subgroup analysis showed similar results for sizes between different MRI fields, temporal resolution, slice thickness and acquisition times, but lower heterogeneity in studies using 3-T MRI (I2 = 57.2%). Results were concordant with low risk of bias studies (2.46, CI 95% [0.57-4.36]), without heterogeneity (I2 = 0%).Therefore, MRI is shown to be an accurate method in pure DCIS size assessment. Once the best MRI protocol is established, evaluation of the impact of pure DCIS size in predicting treatment outcomes will contribute to clarifying current issues related to intraductal breast carcinoma.

Radiological Underestimation of Tumor Size as a Relevant Risk Factor for Positive Margin Rate in Breast-Conserving Therapy of Pure Ductal Carcinoma In Situ (DCIS)

Background: Radiological underestimation of the actual tumor size is a relevant problem in reaching negative margins in ductal carcinoma in situ (DCIS) associated with microcalcifications in breast-conserving therapy (BCT). The aim of this study is to evaluate whether the radiological underestimation of tumor size has an influence on the histopathological margin status. Methods: Patients who underwent BCT with preoperatively diagnosed pure DCIS were included (pooled analysis of two trials). Multiple factors were analysed regarding radiological underestimation ≥10 mm. Radiological underestimation was defined as mammographic minus histological tumor size in mm. Results: Positive margins occurred in 75 of 189 patients. Radiological underestimation ≥10 mm was an independent influencing factor (OR 5.80; 95%CI 2.55−13.17; p < 0.001). A radiological underestimation was seen in 70 patients. The following parameters were statistically significant associated with underestimation: pleomorphic microcalcifications (OR 3.77; 95%CI 1.27−11.18), clustered distribution patterns (OR 4.26; 95%CI 2.25−8.07), and mammographic tumor sizes ≤20 mm (OR 7.47; 95%CI 3.49−15.99). Only a mammographic tumor size ≤20 mm was an independent risk factor (OR 6.49; 95%CI 2.30−18.26; p < 0.001). Grading, estrogen receptor status, and comedo necrosis did not influence the size estimation. Conclusion: Radiological underestimation is an independent risk factor for positive margins in BCT of DCIS associated with microcalcifications predominantly occurring in mammographic small tumors.

Sensitivity of Contrast-Enhanced Breast MRI vs X-ray Mammography Based on Cancer Histology, Tumor Grading, Receptor Status, and Molecular Subtype: A Supplemental Analysis of 2 Large Phase III Studies

Background:

The impact of certain tumor parameters on the sensitivity of imaging tools is unknown. The purpose was to study the impact of breast cancer histology, tumor grading, single receptor status, and molecular subtype on the sensitivity of contrast-enhanced breast magnetic resonance imaging (CE-BMRI) vs X-ray mammography (XRM) to detect breast cancer.

Materials and Methods:

We ran a supplemental analysis of 2 global Phase III studies which recruited patients with histologically proven breast cancers. The sensitivity of CE-BMRI vs XRM to detect cancer lesions with different histologies, tumor grading, single receptor status, and molecular subtype was compared. Six blinded readers for each study evaluated the images. Results were summarized as the “Mean Reader.” For each reader, sensitivity was defined as the proportion of detected lesions vs the total number of lesions identified by the standard of reference. Two-sided 95% confidence intervals were calculated for within-group proportions, and for the difference between CE-BMRI and XRM, using a normal approximation to the binomial distribution.

Results:

In 778 patients, 1273 cancer lesions were detected. A total of 435 patients had 1 lesion, 254 had 2 lesions, and 77 had 3 or more lesions. The sensitivity of CE-BMRI was significantly higher compared with XRM irrespective of the histology. The largest difference was seen for invasive lobular carcinoma (22.3%) and ductal carcinoma in situ (19%). Across all 3 tumor grades, the sensitivity advantage of CE-BMRI over XRM ranged from 15.7% to 18.5%. Contrast-enhanced breast magnetic resonance imaging showed higher sensitivity compared with XRM irrespective of single receptor expressions (15.3%-19.4%). The sensitivities for both imaging methods were numerically higher for the more aggressive ER– (estrogen receptor), PR– (progesterone receptor), and HER2+ (human epidermal growth factor receptor 2) tumors. Irrespective of molecular subtype, sensitivity of CE-BMRI was 14.8% to 18.9% higher compared with XRM.

Conclusions:

Contrast-enhanced breast magnetic resonance imaging showed significantly higher sensitivity compared with XRM independent of tumor histology, tumor grading, single receptor status, and molecular subtype.

Trial Registration: ClinicalTrials.gov: NCT01067976 and NCT01104584.

Background Parenchymal Enhancement on Breast MRI: Assessment and Clinical Implications

Purpose of Review

To present recent literature regarding the assessment and clinical implications of background parenchymal enhancement on breast MRI.

Recent Findings

The qualitative assessment of BPE remains variable within the literature, as well as in clinical practice. Several different quantitative approaches have been investigated in recent years, most commonly region of interest-based and segmentation-based assessments. However, quantitative assessment has not become standard in clinical practice to date. Numerous studies have demonstrated a clear association between higher BPE and future breast cancer risk. While higher BPE does not appear to significantly impact cancer detection, it may result in a higher abnormal interpretation rate. BPE is also likely a marker of pathologic complete response after neoadjuvant chemotherapy, with decreases in BPE during and after neoadjuvant chemotherapy correlated with pCR. In contrast, pre-treatment BPE does not appear to be predictive of pCR. The association between BPE and prognosis is less clear, with heterogeneous results in the literature.

Summary

Assessment of BPE continues to evolve, with heterogeneity in approaches to both qualitative and quantitative assessment. The level of BPE has important clinical implications, with associations with future breast cancer risk and treatment response. BPE may also be an imaging marker of prognosis, but future research is needed on this topic.

Mini review: The FDA-approved prescription drugs that target the MAPK signaling pathway in women with breast cancer

Breast cancer (BC) is the most common cancer and the prevalent type of malignancy among women. Multiple risk factors, including genetic changes, biological age, dense breast tissue, and obesity are associated with BC. The mitogen-activated protein kinases (MAPK) signaling pathway has a pivotal role in regulating biological functions such as cell proliferation, differentiation, apoptosis, and survival. It has become evident that the MAPK pathway is associated with tumorigenesis and may promote breast cancer development. The MAPK/RAS/RAF cascade is closely associated with breast cancer. RAS signaling can enhance BC cell growth and progression. B-Raf is an important kinase and a potent RAF isoform involved in breast tumor initiation and differentiation. Depending on the reasons for cancer, there are different strategies for treatment of women with BC. Till now, several FDA-approved treatments have been investigated that inhibit the MAPK pathway and reduce metastatic progression in breast cancer. The most common breast cancer drugs that regulate or inhibit the MAPK pathway may include Farnesyltransferase inhibitors (FTIs), Sorafenib, Vemurafenib, PLX8394, Dabrafenib, Ulixertinib, Simvastatin, Alisertib, and Teriflunomide. In this review, we will discuss the roles of the MAPK/RAS/RAF/MEK/ERK pathway in BC and summarize the FDA-approved prescription drugs that target the MAPK signaling pathway in women with BC.

Could ultrasound-guided cryoablation be used to manage "low-risk" DCIS?: a feasibility case report

Management of ductal carcinoma in-situ (DCIS) is controversial as there is concern that the majority of diagnoses will never become life threatening such that a subset of patients may be overtreated with surgery. Active surveillance is an alternative proposed management strategy; however, we cannot accurately predict which DCIS will never progress to invasive disease potentially undertreating a large proportion of women. We present a case of a 58-year-old female with DCIS successfully treated with only ultrasound-guided cryoablation without resection. A follow-up needle biopsy of the ablation zone was benign and imaging follow-up has demonstrated no evidence of disease at 14-months. Cryoablation of DCIS is feasible with appropriate patient selection and warrants further investigation as an alternative to surgical resection or active surveillance.

Reliability of MRI tumor size measurements for minimal invasive treatment selection in small breast cancers

INTRODUCTION

Due to the shift towards minimal invasive treatment, accurate tumor size estimation is essential for small breast cancers. The purpose of this study was to determine the reliability of MRI-based tumor size measurements with respect to clinical, histological and radiomics characteristics in small invasive or in situ carcinomas of the breast to select patients for minimal invasive therapy.

MATERIALS AND METHODS

All consecutive cases of cT1 invasive breast carcinomas that underwent pre-operative MRI, treated in two hospitals between 2005 and 2016, were identified retrospectively from the Dutch cancer registry and cross-correlated with local databases. Concordance between MRI-based measurements and final pathological size was analyzed. The influence of clinical, histological and radiomics characteristics on the accuracy of MRI size measurements were analyzed.

RESULTS

Analysis included 343 cT1 breast carcinomas in 336 patients (mean age, 55 years; range, 25-81 years). Overall correlation of MRI measurements with pathology was moderately strong (ρ = 0.530, P < 0.001), in 42 cases (12.2%) MRI underestimated the size with more than 5 mm. Underestimation occurs more often in grade 2 and grade 3 disease than in low grade invasive cancers. In DCIS the frequency of underestimation is higher than in invasive breast cancer. Unfortunately, none of the patient, imaging or biopsy characteristics appeared predictive for underestimation.

CONCLUSION

Size measurements of small breast cancers on breast MRI are within 5 mm of pathological size in 88% of patients. Nevertheless, underestimation cannot be adequately predicted, particularly for grade 2 and grade 3 tumors, which may hinder patient selection for minimal invasive therapy.

Background parenchymal enhancement on breast MRI: A comprehensive review

The degree of normal fibroglandular tissue that enhances on breast MRI, known as background parenchymal enhancement (BPE), was initially described as an incidental finding that could affect interpretation performance. While BPE is now established to be a physiologic phenomenon that is affected by both endogenous and exogenous hormone levels, evidence supporting the notion that BPE frequently masks breast cancers is limited. However, compelling data have emerged to suggest BPE is an independent marker of breast cancer risk and breast cancer treatment outcomes. Specifically, multiple studies have shown that elevated BPE levels, measured qualitatively or quantitatively, are associated with a greater risk of developing breast cancer. Evidence also suggests that BPE could be a predictor of neoadjuvant breast cancer treatment response and overall breast cancer treatment outcomes. These discoveries come at a time when breast cancer screening and treatment have moved toward an increased emphasis on targeted and individualized approaches, of which the identification of imaging features that can predict cancer diagnosis and treatment response is an increasingly recognized component. Historically, researchers have primarily studied quantitative tumor imaging features in pursuit of clinically useful biomarkers. However, the need to segment less well-defined areas of normal tissue for quantitative BPE measurements presents its own unique challenges. Furthermore, there is no consensus on the optimal timing on dynamic contrast-enhanced MRI for BPE quantitation. This article comprehensively reviews BPE with a particular focus on its potential to increase precision approaches to breast cancer risk assessment, diagnosis, and treatment. It also describes areas of needed future research, such as the applicability of BPE to women at average risk, the biological underpinnings of BPE, and the standardization of BPE characterization. Level of Evidence: 3 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2020;51:43-61.