Breast MRI in Invasive Lobular Carcinoma: A Useful Investigation in Surgical Planning?

Guideline-Concordant Surgical Care for Lobular Versus Ductal Inflammatory Breast Cancer

INTRODUCTION

Quality of surgical care is understudied for lobular inflammatory breast cancer (IBC), which is less common, more chemotherapy-resistant, and more mammographically occult than ductal IBC. We compared guideline-concordant surgery (modified radical mastectomy [MRM] without immediate reconstruction following chemotherapy) for lobular versus ductal IBC.

METHODS

 Female individuals with cT4dM0 lobular and ductal IBC were identified in the National Cancer Database (NCDB) from 2010-2019. Modified radical mastectomy receipt was identified via codes for "modified radical mastectomy" or "mastectomy" and "≥10 lymph nodes removed" (proxy for axillary lymph node dissection). Descriptive statistics, chi-square tests, and t-tests were used.

RESULTS

A total of 1456 lobular and 10,445 ductal IBC patients were identified; 599 (41.1%) with lobular and 4859 (46.5%) with ductal IBC underwent MRMs (p = 0.001). Patients with lobular IBC included a higher proportion of individuals with cN0 disease (20.5% lobular vs. 13.7% ductal) and no lymph nodes examined at surgery (31.2% vs. 24.5%) but were less likely to be node-negative at surgery (12.7% vs. 17.1%, all p < 0.001). Among those who had lymph nodes removed at surgery, patients with lobular IBC also had fewer lymph nodes excised versus patients with ductal IBC (median [interquartile range], 7 (0-15) vs. 9 (0-17), p = 0.001).

CONCLUSIONS

Lobular IBC patients were more likely to present with node-negative disease and less likely to be node-negative at surgery, despite having fewer, and more frequently no, lymph nodes examined versus ductal IBC patients. Future studies should investigate whether these treatment disparities are because of surgical approach, pathologic assessment, and/or data quality as captured in the NCDB.

The impact of preoperative breast MRI on the therapeutic management of breast cancer patients

BACKGROUND

The role of preoperative breast MRI to evaluate the extent of disease in breast cancer patients is considered controversial. We aimed at assessing the effect of breast MRI on the management of newly diagnosed breast cancer.

MATERIALS

A retrospective review of 202 consecutively seen patients who were newly diagnosed with breast cancer and who underwent preoperative breast MRIs at Assuta Ashdod between June 1, 2017, and June 1, 2020. Data included discovering suspicious lesions by conventional imaging, MRI findings, and surgical pathology results. This was analyzed to determine whether the MRI changed the management and whether it had a justified or unjustified effect on the treatment.

RESULTS

The mean age was 54.51 (standard deviation, 11.34 years). Breast MRI revealed additional findings in 56 % of patients and modified therapeutic management in 32 % of the cases evaluated, having a justified effect in 87.6 %. Patients with changed management had a statistically significantly higher mastectomy rate (36 %) than those who did not (14 %). No statistically significant association was found between independent variables such as breast density, tumor location on the breast, type of tumor, patient's demographic information, etc. And whether MRI findings changed the initial treatment plan.

CONCLUSIONS

MRI played an essential role in the preoperative staging of breast cancer in our study, modifying therapeutic planning in approximately one-third of the cases and having a justified effect on most of them. We, therefore, support preoperative breast MRI in newly diagnosed breast cancer patients.

PROMRIINE (PRe-operatory Magnetic Resonance Imaging is INEffective) Study: A Systematic Review and Meta-analysis of the Impact of Magnetic Resonance Imaging on Surgical Decisions and Clinical Outcomes in Women with Breast Cancer

BACKGROUND

The purpose of this study was to review and summarize the association between preoperative magnetic resonance imaging (MRI) and surgical outcomes in women with newly diagnosed invasive breast cancer from published randomized controlled trials (RCT).

MATERIALS AND METHODS

Two independent researchers conducted a systematic review through a comprehensive search of electronic databases, including PubMed, Medline, Embase, Ovid, Cochrane Library, and Web of Science. If there was disagreement between the two reviewers, a third reviewer assessed the manuscript to determine whether it should be included for data extraction. The quality of the papers was assessed using the risk of bias tool, and the evidence was analyzed using GRADE. Meta-analyses using a fixed-effects model were used to estimate the pooled risk ratio (RR) and 95% confidence interval (CI).

RESULTS

Initially, 21 studies were identified, 15 of which were observational comparative studies. A total of five RCTs were included, and they suggested that preoperative MRI significantly reduced the rate of immediate breast-conserving surgery and increased the risk for mastectomy.

CONCLUSIONS

From the RCT perspective, preoperative MRI for newly diagnosed invasive breast cancer did not improve surgical outcomes and may increase the risk of mastectomy.

Literature review on the bilateral occurrence of invasive lobular breast cancer

Historically, it has been believed that invasive lobular carcinomas (ILC) occur more frequently bilaterally compared to other invasive subtypes, with estimates ranging between 20% and 29%. This study aims to determine if this historical perspective still holds true. A comprehensive literature review was conducted to examine the bilateral occurrence of lobular carcinoma using various imaging methods. Additionally, the role of magnetic resonance imaging (MRI) in detecting contralateral carcinomas was also investigated. A comprehensive search was conducted in the MedLine database on the PubMed platform, resulting in 307 articles published between January 1, 2014, and January 1, 2023. Various selection criteria were applied to identify articles relevant to the research question. After careful assessment, eight articles remained that met the eligibility criteria, all of which provided level-three evidence and were therefore included in the literature review. A total of 599 patients were included in this review, comprising a total of 602 cases of ILC. Six out of the eight articles reviewed provided information on the bilateral occurrence of ILC based on histopathology. A weighted average calculation yielded a bilaterality percentage of 4.95% (24 out of 485 cases). Four articles reported the number of bilateral cases identified through MRI, resulting in a weighted average of 10.2% (26 out of 255 cases). It is worth noting that 20.4% (100 out of 491) of the performed MRIs were found to be either useless or even harmful. Furthermore, MRI led to a change in the treatment plan in 27.7% (136 out of 491) of cases. Overall, it can be concluded that there is limited available data regarding the bilateral occurrence of ILC. The numbers found in the literature are also inconsistent and tend to vary. The literature review revealed a decrease in the percentage of bilaterality compared to historical beliefs. Based on this study, it can be concluded that a high number of MRI scans were found to be either useless or harmful. As a result of this conclusion and a higher sensitivity of other screening modalities, MRI may no longer be indicated as part of the standard workup for ILC. However, further research is necessary to validate these findings.

Retrospective cohort study on the bilateral occurrence of invasive lobular breast cancer

OBJECTIVE

Invasive lobular carcinoma (ILC) is the second most common histological subtype of invasive breast cancer, following the no special type (NST) invasive carcinoma. It has historically been assumed that ILC occurs bilaterally in 20-29 % of cases, which has influenced the inclusion of MRI in the standard workup of ILC according to European guidelines. However, challenging this long-held belief regarding the bilateral occurrence of ILC opens up the possibility of revising the guidelines and using MRI only for more specific indications. This study aims to evaluate whether the previously reported high percentage of bilaterality still holds true and to question the added value of MRI in the standard workup of ILC.

STUDY DESIGN

A retrospective cohort study was conducted following approval from the institutional review board (EC 21/18/249) at Antwerp University Hospital (UZA). The cohort comprised female patients of all ages who had been diagnosed with either ILC or NST invasive carcinoma and had sought consultation at the UZA breast clinic. A comprehensive database was established to collect information on patient characteristics, imaging, and pathology.

RESULTS

A total of 271 patients with ILC were included in the study, with incidence dates ranging from 01/01/2007 to 01/01/2023. Among these patients, a synchronous bilateral ILC lesion was observed in 1.85 % (5/271) of cases. This proportion is significantly lower than the reported percentage of patients with a bilateral lesion in the literature population, which stands at 4.95 %. The reference group consisted of 809 patients with NST invasive carcinoma, with incidence dates ranging from 01/01/2017 to 01/01/2023. In the control group, a synchronous bilateral NST lesion was observed in 3.96 % (32/809) of cases. There is no significant difference in the bilaterality rates between the group of ILC patients and the group of NST patients. Furthermore, MRI did not detect any histopathologically confirmed contralateral ILC lesion that had not already been detected by mammography or ultrasound.

CONCLUSIONS

The study results indicate a lower occurrence of bilateral ILC than previously assumed. Additionally, the incidence of synchronous bilateral lesions in ILC patients is not higher compared to patients with NST invasive carcinoma. Performing an MRI does not provide additional value in detecting bilateral carcinomas in ILC. Consequently, it is recommended that the current European guidelines be reassessed, and the indications for undergoing an MRI should be adjusted accordingly.

The Role of Magnetic Resonance Imaging in the Preoperative Staging and Treatment of Invasive Lobular Carcinoma

INTRODUCTION

Invasive lobular carcinoma (ILC) is known for its diffuse growth pattern and its associated challenges in diagnosing. Magnetic resonance imaging (MRI) is the most accurate imaging modality and might aid in improving preoperative staging compared to full field digital mammography (FFDM) and ultrasound (US), however current literature is inconsistent. The aim of this paper is to evaluate the accuracy of MRI staging compared to FFDM/US and pathology results.

METHODS

In this single-centre retrospective study, all patients diagnosed with ILC between 2014 and 2019 who underwent preoperative MRI were included. Specific parameters studied were: (1) the need for second-look targeted biopsies, (2) detection of new tumors (ie, contralateral or multifocal), (3) changes in cTNM-classification, and (4) impact on final treatment plan. Bland-Altman plots were used to compare the tumor sizes measured on MRI and FFDM/US with actual pathological tumor sizes.

RESULTS

Ninety-nine patients were included. After performing preoperative MRI, 9 (9.1%) multifocal tumors were diagnosed after additional biopsies. Contralateral tumors were detected twice (2.0%) and cN classification was upgraded in 7 cases (7.1%). Surgical treatment or neoadjuvant treatment plans were changed in 16 patients (16.1%). Compared to histopathological results, FFDM/US underestimated tumor size with a mean of 0.4 cm (Limit of agreement (LoA): -2.8 cm to 2.0 cm) whereas MRI overestimated tumor size with a mean of 0.6 cm (LoA: -1.9 cm to 3.0 cm).

CONCLUSIONS

In our study, mean differences in tumor size measurements using FFDM/US and MRI were comparable, with similar random errors. MRI correctly diagnosed multifocal and contralateral tumors more often and provided a better cN staging.

ACR Appropriateness Criteria® Imaging of Invasive Breast Cancer

As the proportion of women diagnosed with invasive breast cancer increases, the role of imaging for staging and surveillance purposes should be determined based on evidence-based guidelines. It is important to understand the indications for extent of disease evaluation and staging, as unnecessary imaging can delay care and even result in adverse outcomes. In asymptomatic patients that received treatment for curative intent, there is no role for imaging to screen for distant recurrence. Routine surveillance with an annual 2-D mammogram and/or tomosynthesis is recommended to detect an in-breast recurrence or a new primary breast cancer in women with a history of breast cancer, and MRI is increasingly used as an additional screening tool in this population, especially in women with dense breasts. The American College of Radiology 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 where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Discriminative Factors of Malignancy of Ipsilateral Nonmass Enhancement in Women With Newly Diagnosed Breast Cancer on Initial Staging Breast MRI

BACKGROUND

Nonmass enhancement (NME) on breast MRI impacts surgical planning.

PURPOSE

To evaluate positive predictive values (PPVs) and identify malignancy discriminators of NME ipsilateral to breast cancer on initial staging MRI.

STUDY TYPE

Retrospective.

SUBJECTS

Eighty-six women (median age, 48 years; range, 26-75 years) with 101 NME lesions (BI-RADS 4 and 5) ipsilateral to known cancers and confirmed histopathology.

FIELD STRENGTH/SEQUENCE

1.5 T and 3.0 T dynamic contrast-enhanced fat-suppressed T1-weighted fast spoiled gradient-echo.

ASSESSMENT

Three radiologists blinded to pathology independently reviewed MRI features (distribution, internal enhancement pattern, and enhancement kinetics) of NME, locations relative to index cancers (contiguous, non-contiguous, and different quadrants), associated mammographic calcifications, lymphovascular invasion (LVI), axillary node metastasis, and radiology-pathology correlations. Clinical factors, NME features, and cancer characteristics were analyzed for associations with NME malignancy.

STATISTICAL TESTS

Fisher's exact, Chi-square, Wilcoxon rank sum tests, and mixed-effect multivariable logistic regression were used. Significance threshold was set at P < 0.05.

RESULTS

Overall NME malignancy rate was 48.5% (49/101). Contiguous NME had a significantly higher malignancy rate (86.7%) than non-contiguous NME (25.0%) and NME in different quadrants (10.7%), but no significant difference was observed by distance from cancer for non-contiguous NME, P = 0.68. All calcified NME lesions contiguous to the calcified index cancer were malignant. NME was significantly more likely malignant when index cancers were masses compared to NME (52.9% vs. 21.4%), had mammographic calcifications (63.2% vs. 39.7%), LVI (81.8% vs. 44.4%), and axillary node metastasis (70.8% vs. 41.6%). NME features with highest PPVs were segmental distribution (85.7%), clumped enhancement (66.7%), and nonpersistent kinetics (77.1%). On multivariable analysis, contiguous NME, segmental distribution, and nonpersistent kinetics were associated with malignancy.

DATA CONCLUSION

Malignancy discriminators of ipsilateral NME on staging MRI included contiguous location to index cancers, segmental distribution, and nonpersistent kinetics.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

The Impact of Preoperative Breast MRI on Timing of Surgical Management in Newly Diagnosed Breast Cancer

Purpose: Preoperative breast MRI has been recommended at our center since 2016 for invasive lobular carcinoma and cancers in dense breasts. This study examined how preoperative breast MRI impacted surgical timing and outcomes for patients with newly diagnosed breast cancer. Methods: Retrospective single-center study of consecutive women diagnosed with new breast cancer between June 1, 2019, and March 1, 2021, in whom preoperative breast MRI was recommended. MRI, tumor histology, breast density, post-MRI biopsy, positive predictive value of biopsy (PPV3), surgery, and margin status were recorded. Time from diagnosis to surgery was compared using t-tests. Results: There were 1054 patients reviewed, and 356 were included (mean age 60.9). Of these, 44.4% (158/356) underwent preoperative breast MRI, and 55.6% (198/356) did not. MRI referral was more likely for invasive lobular carcinoma, multifocal disease, and younger patients. Following preoperative MRI, 29.1% (46/158) patients required additional breast biopsies before surgery, for a PPV3 of 37% (17/46). The time between biopsy and surgery was 55.8 ± 21.4 days for patients with the MRI, compared to 42.8 ± 20.3 days for those without (P < .00001). MRI was not associated with the type of surgery (mastectomy vs breastconserving surgery) (P = .44) or rate of positive surgical margins (P = .52). Conclusion: Among patients who underwent preoperative breast MRI, we observed significant delays to surgery by almost 2 weeks. When preoperative MRI is requested, efforts should be made to mitigate associated delays.

Defining features of hereditary lobular breast cancer due to CDH1 with magnetic resonance imaging and tumor characteristics

Women with germline pathogenic variants in CDH1, which encodes E-cadherin protein, are at increased lifetime risk of invasive lobular carcinoma (ILC). The associated tumor characteristics of hereditary lobular breast carcinoma (HLBC) in this high-risk population are not well-known. A single-center prospective cohort study was conducted to determine the imaging and pathologic features of HLBC compared to population-based ILC using Surveillance, Epidemiology, and End Results (SEER) data. One hundred fifty-eight women with CDH1 variants were evaluated, of whom 48 (30%) also had an ILC diagnosis. The median age at CDH1 diagnosis was 45 years [interquartile range, IQR 34-57 years] whereas the median age at diagnosis of CDH1 with concomitant ILC (HLBC) was 53 [IQR 45-62] years. Among women with HLBC, 83% (40/48) were identified with CDH1 mutation after diagnosis of ILC. Among 76 women (48%, 76/158) undergoing surveillance for ILC with breast magnetic resonance imaging (MRI), 29% (22/76) had an abnormal MRI result with available biopsy data for comparison. MRI detected ILC in 7 out of 8 biopsy-confirmed cases, corresponding with high sensitivity (88%), specificity (75%), and negative predictive value (98%); however, false-positive and false-discovery rates were elevated also (25% and 68%, respectively). HLBC was most frequently diagnosed at age 40-49 years (44%, 21/48), significantly younger than the common age of diagnosis of ILC in SEER general population data (most frequent age range 60-69 years, 28%; p < 0.001). HLBC tumors were smaller than SEER-documented ILC tumors (median 1.40 vs. 2.00 cm; p = 0.002) and had a higher incidence of background lobular carcinoma in situ (88% vs. 1%; p < 0.001) as well as progesterone receptor positivity (95% vs. 81%, p = 0.032). These findings suggest that HLBC is often detected via conventional screening methods as an early-stage hormone receptor-positive tumor, thus the clinical benefit of intensive screening with MRI may be limited to a subset of women with germline CDH1 variants.

Invasive lobular carcinoma of the breast detected with real-time virtual sonography: a case report

BACKGROUND

Invasive lobular carcinoma (ILC) sometimes presents with unique clinical, pathologic, and radiographic features. In this case report, we describe a patient with ILC, whose initial presentation consisted with symptoms secondary to bone-marrow dissemination. In addition, the breast primary was revealed only by magnetic resonance imaging (MRI) followed by real-time virtual sonography (RVS).

CASE PRESENTATION

A 51-year-old woman presented to our outpatient clinic with dyspnea on exertion. She had severe anemia (hemoglobin, 5.3 g/dL) and thrombocytopenia (platelet count, 31 × 10³/mL). Bone-marrow biopsy was performed to evaluate hematopoietic function. The pathologic diagnosis was bone-marrow carcinomatosis due to metastatic breast cancer. Initial mammography followed by ultrasonography (US) failed to detect the primary tumor. On MRI, a non-mass-enhancement lesion was observed. While second-look US also did not detect the lesion, it was clearly visualized with RVS. We were finally able to biopsy the breast lesion. The pathologic diagnosis was ILC positive for both estrogen receptor and progesterone receptor, with 1 + immunohistochemical staining for human epidermal growth factor receptor 2. This case of ILC was characterized by bone-marrow metastasis. Due to decreased cell adhesion, the risk of bone-marrow metastasis is higher in ILC than in invasive ductal carcinoma, the most prevalent type of breast cancer. Biopsy of the primary lesion, which was initially only detected with MRI, was successfully performed with clear visualization during RVS, which is based on the fusion of MRI and US images.

CONCLUSION

In this case report and literature review, we describe the unique clinical characteristics of ILC and a strategy for identifying primary lesions that are initially only visualized with MRI.

Invasive Lobular Carcinoma: A Review of Imaging Modalities with Special Focus on Pathology Concordance

Invasive lobular cancer (ILC) is the second most common type of breast cancer. It is characterized by a unique growth pattern making it difficult to detect on conventional breast imaging. ILC can be multicentric, multifocal, and bilateral, with a high likelihood of incomplete excision after breast-conserving surgery. We reviewed the conventional as well as newly emerging imaging modalities for detecting and determining the extent of ILC- and compared the main advantages of MRI vs. contrast-enhanced mammogram (CEM). Our review of the literature finds that MRI and CEM clearly surpass conventional breast imaging in terms of sensitivity, specificity, ipsilateral and contralateral cancer detection, concordance, and estimation of tumor size for ILC. Both MRI and CEM have each been shown to enhance surgical outcomes in patients with newly diagnosed ILC that had one of these imaging modalities added to their preoperative workup.

Digital Breast Tomosynthesis versus MRI as an Adjunct to Full-Field Digital Mammography for Preoperative Evaluation of Breast Cancer according to Mammographic Density

OBJECTIVE

To compare digital breast tomosynthesis (DBT) and MRI as an adjunct to full-field digital mammography (FFDM) for the preoperative evaluation of women with breast cancer based on mammographic density.

MATERIALS AND METHODS

This retrospective study enrolled 280 patients with breast cancer who had undergone FFDM, DBT, and MRI for preoperative local tumor staging. Three radiologists independently sought the index cancer and additional ipsilateral and contralateral breast cancers using either FFDM alone, DBT plus FFDM, or MRI plus FFDM. Diagnostic performances across the three radiologists were compared among the reading modes in all patients and subgroups with dense (n = 186) and non-dense breasts (n = 94) according to mammographic density.

RESULTS

Of 280 patients, 46 (16.4%) had 48 additional (39 ipsilateral and nine contralateral) cancers in addition to the index cancer. For index cancers, both DBT plus FFDM and MRI plus FFDM showed sensitivities of 100% in the non-dense group. In the dense group, DBT plus FFDM showed lower sensitivity than that of MRI plus FFDM (94.6% vs. 99.6%, p < 0.001). For additional ipsilateral cancers, DBT plus FFDM showed specificity and positive predictive value (PPV) of 100% in the non-dense group, but sensitivity and negative predictive value (NPV) were not statistically different from those of MRI plus FFDM (p > 0.05). In the dense group, DBT plus FFDM showed higher specificity (98.2% vs. 94.1%, p = 0.005) and PPV (83.1% vs. 65.4%; p = 0.036) than those of MRI plus FFDM, but lower sensitivity (59.9% vs. 75.3%; p = 0.049). For contralateral cancers, DBT plus FFDM showed higher specificity than that of MRI plus FFDM (99.0% vs. 96.7%, p = 0.014), however, the other values did not differ (all p > 0.05) in the dense group.

CONCLUSION

DBT plus FFDM showed an overall higher specificity than that of MRI plus FFDM regardless of breast density, perhaps without substantial loss in sensitivity and NPV in the diagnosis of additional cancers. Thus, DBT may have the potential to be used as a preoperative breast cancer staging tool.

MRI background parenchymal enhancement in patients with invasive lobular carcinoma: Endocrine hormonal treatment effect

OBJECTIVES

High background parenchymal enhancement (BPE) levels and asymmetric distribution could cause diagnostic uncertainty due to morphological similarity to breast cancer, especially invasive lobular carcinoma (ILC). We investigated BPE in ILC patients, its association with the tumor hormonal profile, and the effect of endocrine treatment (ET).

METHODS

The analysis included all MRI examinations performed at our institution between 2010 and 2019 for ILC-diagnosed patients. Baseline study and the first follow-up study were reviewed. Digital medical records were reviewed to retrieve demographics/pathology results/treatment information. BPE and fibroglandular tissue were assessed qualitatively on the contralateral breast according to the criteria of the Breast Imaging Reporting and Data System (BI-RADS).

RESULTS

The study included 129 patients. Most (91%) had pure ILC. All received ET; 12% also received chemotherapy; 90% had surgery first; 70% by breast conservation. On the baseline MRI, 70% had mild or moderate BPE; whereas, on the follow-up study, the majority (59%) had minimal BPE. Most BPE reductions were by 2 degrees. In the baseline study, additional biopsies were required in 59% of cases, and in 17%, a short-term follow-up was recommended. In the follow-up study, biopsies were recommended in 10%, and a short-term follow-up was requested in 16%. A correlation between progesterone receptor intensity index and baseline BPE level was observed (r = 0.3, p = 0.004).

CONCLUSION

ILC patients usually exhibit high BPE. ET decreases BPE, and therefore may decrease false-positive interpretations. Additional research is needed to explore whether study can be performed on ET without compromising sensitivity.

KEY POINTS

∙ High background parenchymal enhancement levels reduces breast MRI sensitivity, yielding high false positive rates especially when reporting cases of invasive lobular carcinoma [ILC].∙Treatment of ILC with endocrine therapy reduces background parenchymal enhancement and thus could decrease these false-positive interpretations.

Contrast enhanced mammography (CEM) versus magnetic resonance imaging (MRI) for staging of breast cancer: The pro CEM perspective

In women with newly diagnosed breast cancer, preoperative staging is required to assess disease extent, enabling us to decide on the most optimal treatment strategy. For locoregional staging, assessment of intramammary tumor extent and presence of axillary and perhaps also internal mammary lymph node metastases is required. Due to the similarity in the underlying principle, contrast-enhanced mammography is increasingly considered instead of breast MRI for this purpose. When considering the combination of CEM and US as a single appointment imaging strategy for preoperative staging of breast cancer, there is only limited room for an additional benefit of breast MRI. For tumor size measurements, equal performance of both CEM and MRI are observed. Sensitivity of both techniques for detecting breast cancer is comparable, meaning that both techniques are capable of detecting additional ipsilateral or contralateral tumor foci. However, specificity is in favor of CEM, meaning that there is a slightly lower chance of having false positive findings in preoperative staging of the breast. Axillary US can be performed during the same appointment as CEM, with equal performance and limitations as evaluation of the axilla on standard breast MRI examinations. Finally, there is no need to actively pursue the detection of IMLN metastases, meaning that additional MRI to do so is not required. This review provides a 'pro-CEM' perceptive on the arguments why breast MRI is hardly necessary when CEM in combination with US has been performed as a single appointment imaging strategy in breast cancer patients.

Axillary Nodal Metastases in Invasive Lobular Carcinoma Versus Invasive Ductal Carcinoma: Comparison of Node Detection and Morphology by Ultrasound

Background: Invasive lobular carcinoma is more subtle on imaging compared with invasive ductal carcinoma; nodal metastases may also differ on imaging between these. Objective: To determine whether invasive lobular carcinoma and invasive ductal carcinoma differ in the detection rate by ultrasound (US) of metastatic axillary nodes and in metastatic nodes' US characteristics. Methods: This retrospective study included 695 women (median age 53 years) with breast cancer in a total of 723 breasts (76 lobular, 586 ductal, 61 mixed), with biopsy-proven axillary nodal metastases and who underwent pretreatment US. A single breast radiologist reviewed US images in patients with suspicious nodes on US and classified node number, size, and morphology. Morphologic assessment used a previously described classification based on the relationship between node cortex and hilum. Nodal findings were compared between lobular and ductal carcinoma. A second radiologist independently classified node morphology in 241 cancers to assess interreader agreement. Results: A total of 99 metastatic axillary nodes (15 lobular, 66 ductal, 18 mixed) were not visualized on US and were diagnosed by surgical biopsy. The remaining 624 metastatic nodes (61 lobular, 520 ductal, 43 mixed) were visualized on US and diagnosed by US-guided FNA. Thus, US detected the metastatic nodes in 80.3% for lobular carcinoma versus 88.7% for ductal carcinoma (p=.04). Among metastatic nodes detected by US, retrospective review identified ≥3 abnormal nodes in 50.8% of lobular carcinoma versus 69.2% of ductal carcinoma (p=.003); node size was ≤2.0 cm in 65.6% for lobular carcinoma versus 47.3% for ductal carcinoma (p=.03); morphology was type III/IV (diffuse cortical thickening without hilar mass effect) rather than type V/VI (marked cortical thickening with hilar mass effect) in 68.9% for lobular carcinoma versus 28.8% for ductal carcinoma (p<.001). Interreader agreement assessment for morphology exhibited kappa coefficient of 0.63 (95% CI, 0.54-0.73). Conclusion: US detects a lower percentage of nodal metastases in lobular than ductal carcinoma. Nodal metastases in lobular carcinoma more commonly show diffuse cortical thickening and with less hilar mass effect. Clinical Impact: A lower threshold may be warranted to recommend biopsy of suspicious axillary nodes detected on US in patients with lobular carcinoma.

The selective use of preoperative MRI in the staging of breast cancer: a single-institution experience

INTRODUCTION

Routine use of preoperative breast magnetic resonance imaging (MRI) for loco-regional staging of breast cancer remains controversial. At Counties Manukau District Health Board (CMDHB), preoperative breast MRI is used selectively within a multidisciplinary setting. The purpose of this study is to determine the accuracy of selective use of preoperative MRI in staging loco-regional disease and how it has impacted our clinical practice.

METHODS

Patients who received preoperative MRI at CMDHB between October 2015 and October 2018 were identified on a prospective database. The decision to offer MRI was made by multidisciplinary consensus. Patient data were collected retrospectively from clinical, imaging and histology records. The accuracy of MRI was determined by comparing it against histology as gold standard, and its potential contribution to treatment decisions and treatment delay was determined by clinical record review.

RESULTS

Ninety-two patients received preoperative MRI. Additional foci of cancer were identified in ten patients (11%). Sixteen patients (17%) required additional biopsies. In fourteen patients (15%), MRI identified more extensive disease than conventional imaging prompting a change of surgical management. This 'upstaging' was confirmed histologically in twelve (13%). In one (1%) patient, MRI incorrectly 'downstaged' disease, but it did not alter the management. No patients experienced a delay in treatment due to MRI.

CONCLUSION

A selective, considered use of preoperative MRI within a multidisciplinary setting at our local institution results in more biopsies but with an acceptable risk-benefit ratio. It provides accurate staging to aid treatment decisions without resulting in a delay in treatment.

Accuracy of Preoperative Breast MRI Versus Conventional Imaging in Measuring Pathologic Extent of Invasive Lobular Carcinoma

OBJECTIVE

To determine whether invasive lobular carcinoma (ILC) extent is more accurately depicted with preoperative MRI (pMRI) than conventional imaging (mammography and/or ultrasound).

METHODS

After IRB approval, we retrospectively identified women with pMRIs (February 2005 to January 2014) to evaluate pure ILC excluding those with ipsilateral pMRI BI-RADS 4 or 5 findings or who had neoadjuvant chemotherapy. Agreement between imaging and pathology sizes was summarized using Bland-Altman plots, absolute and percent differences, and the intraclass correlation coefficient (ICC). Rates of underestimation and overestimation were evaluated and their associations with clinical features were explored.

RESULTS

Among the 56 women included, pMRI demonstrated better agreement with pathology than conventional imaging by mean absolute difference (1.6 mm versus -7.8 mm, P < 0.001), percent difference (10.3% versus -16.4%, P < 0.001), and ICC (0.88 versus 0.61, P = 0.019). Conventional imaging more frequently underestimated ILC span than pMRI using a 5 mm difference threshold (24/56 (43%) versus 10/56 (18%), P < 0.001), a 25% threshold (19/53 (36%) versus 10/53 (19%), P = 0.035), and T category change (17/56 (30%) versus 7/56 (13%), P = 0.006). Imaging-pathology size concordance was greater for MRI-described solitary masses than other lesions for both MRI and conventional imaging (P < 0.05). Variability of conventional imaging was lower for patients ≥ the median age of 62 years than for younger patients (SD: 12 mm versus 22 mm, P = 0.012).

CONCLUSION

MRI depicts pure ILC more accurately than conventional imaging and may have particular value for younger women.

Accuracy of breast MRI in evaluating nodal status after neoadjuvant therapy in invasive lobular carcinoma

Neoadjuvant therapy in breast cancer can downstage axillary lymph nodes and reduce extent of axillary surgery. As such, accurate determination of nodal status after neoadjuvant therapy and before surgery impacts surgical management. There are scarce data on the diagnostic accuracy of breast magnetic resonance imaging (MRI) for nodal evaluation after neoadjuvant therapy in patients with invasive lobular carcinoma (ILC), a diffusely growing tumor type. We retrospectively analyzed patients with stage 1–3 ILC who underwent pre-operative breast MRI after either neoadjuvant chemotherapy or endocrine therapy at our institution between 2006 and 2019. Two breast radiologists reviewed MRIs and evaluated axillary nodes for suspicious features. All patients underwent either sentinel node biopsy or axillary dissection. We evaluated sensitivity, specificity, negative and positive predictive values, and overall accuracy of the post-treatment breast MRI in predicting pathologic nodal status. Of 79 patients, 58.2% received neoadjuvant chemotherapy and 41.8% neoadjuvant endocrine therapy. The sensitivity and negative predictive value of MRI were significantly higher in the neoadjuvant endocrine therapy cohort than in the neoadjuvant chemotherapy cohort (66.7 vs. 37.9%, p = 0.012 and 70.6 vs. 40%, p = 0.007, respectively), while overall accuracy was similar. Upstaging from clinically node negative to pathologically node positive occurred in 28.0 and 41.7%, respectively. In clinically node positive patients, those with an abnormal post-treatment MRI had a significantly higher proportion of patients with ≥4 positive nodes on pathology compared to those with a normal MRI (61.1 versus 16.7%, p = 0.034). Overall, accuracy of breast MRI for predicting nodal status after neoadjuvant therapy in ILC was low in both chemotherapy and endocrine therapy cohorts. However, post-treatment breast MRI may help identify patients with a high burden of nodal disease (≥4 positive nodes), which could impact pre-operative systemic therapy decisions. Further studies are needed to assess other imaging modalities to evaluate for nodal disease following neoadjuvant therapy and to improve clinical staging in patients with ILC.

A nomogram for determining the disease-specific survival in invasive lobular carcinoma of the breast: A population study

We aimed to establish and validate a nomogram for predicting the disease-specific survival of invasive lobular carcinoma (ILC) patients.The Surveillance, Epidemiology, and End Results program database was used to identify ILC from 2010 to 2015, in which the data was extracted from 18 registries in the US. Multivariate Cox regression analysis was performed to identify independent prognostic factors and a nomogram was constructed to predict the 3-year and 5-year survival rates of ILC patients based on Cox regression. Predictive values were compared between the new model and the American Joint Committee on Cancer staging system using the concordance index, calibration plots, integrated discrimination improvement, net reclassification improvement, and decision-curve analyses.In total, 4155 patients were identified. After multivariate Cox regression analysis, nomogram was established based on a new model containing the predictive variables of age, the primary tumor site, histology grade, American Joint Committee on Cancer TNM (tumor node metastasis) stages II, III, and IV, breast cancer subtype, therapy modality (surgery and chemotherapy). The concordance index for the training and validation cohorts were higher for the new model (0.781 and 0.832, respectively) than for the old model (0.733 and 0.779). The new model had good performance in the calibration plots. Net reclassification improvement and integrated discrimination improvement were also improved. Finally, decision-curve analyses demonstrated that the nomogram was clinically useful.We have developed a reliable nomogram for determining the prognosis and treatment outcomes of ILC. The new model facilitates the choosing of superior medical examinations and the optimizing of therapeutic regimens with cooperation among oncologists.

Does the Addition of Breast MRI Add Value to the Diagnostic Workup of Invasive Lobular Carcinoma?

BACKGROUND

Invasive lobular carcinoma (ILC) has unique histologic growth pattern. Few studies have focused on the value of breast magnetic resonance imaging (MRI) specifically for ILC. We hypothesized that MRI adds value to the diagnostic workup in ILC by better defining the extent of disease and identifying additional foci of malignancy, which can change the surgical plan.

MATERIALS AND METHODS

This was a single-institution retrospective review of women diagnosed with ILC from 1/2012 to 7/2019 who underwent preoperative MRI. Patient, tumor characteristics, and initial surgical plan were reviewed. MRI had added value if ILC size correlated best to final pathologic size or if additional malignancy was identified. MRI was considered harmful if additional biopsies were benign or if the size was overestimated.

RESULTS

ILC was identified in 166 breasts in 165 women. Original surgical plan was for lumpectomy in 86 (52%), mastectomy in 49 (30%), and undecided in 31 (18%). MRI changed the plan in 25 (19%) with 24 (96%) changing from lumpectomy to mastectomy. Additional biopsy was performed in 28% after MRI, the majority (n = 41, 72%) were benign or high risk and 16 (28%) identified additional malignancy. MRI was not a better size estimate than mammogram/ultrasound. Re-excision rate after lumpectomy was 6.8% (5/73). MRI added value in 48 (28.9%) and was harmful in 48 (28.9%).

CONCLUSIONS

Using breast MRI in the diagnostic workup of ILC has both positive and negative implications on surgical treatment planning. A shared decision-making conversation is warranted before proceeding with MRI to maximize value and minimize harms associated with this diagnostic tool.

Predictive factors of major deviation (>20 mm) between lesion sizes measured by magnetic resonance imaging and histology for invasive lobular breast cancer

OBJECTIVE

To identify factors predictive of high discordance (>20 mm) between lesion sizes measured by magnetic resonance imaging (MRI) and histology for invasive lobular breast cancer.

MATERIALS AND METHODS

Data for all women with invasive lobular breast cancer (pure or associated with a component of invasive ductal carcinoma) between 1st January 2007 and 31st December 2016 were included in this study. Logistic regression analysis was performed to determine factors predictive of high discordance (underestimation/overestimation by >20 mm) between tumour sizes measured by MRI and histology for invasive lobular breast cancer.

RESULTS

For overestimation, significant factors on univariate analysis were: menopausal status [odds ratio (OR) 0.27, 95 % confidence interval (CI) 0.10-0.71]; p = 0.01], hormone receptor (HR) status (HR negative, OR 1.64, 95 % CI 0.27-9.89; HR positive, OR 0.64, 95 % CI 0.21-1.88; p = 0.09) and neoadjuvant chemotherapy (OR 10.33, 95 % CI 3.58-29.8; p < 0.001). On multivariate analysis, menopausal status and neoadjuvant chemotherapy were found to be independent predictive factors of overestimation. For underestimation, significant factors on univariate analysis were: histological size (OR 1.05, 95 % CI 1.02-1.08; p < 0.0001) and the presence of an in-situ component (OR 4.66, 95 % CI 1.01-21.5; p = 0.02). These two factors were independent predictive factors of underestimation.

CONCLUSION

Independent predictive factors of overestimation/underestimation (threshold 20 mm) of tumour sizes measured by MRI compared with histology for invasive lobular breast cancer were identified.

Measuring Tumor Extent Based on Subtypes Using Magnetic Resonance Imaging: Radiologic-Pathologic Discordance and High Positive Margin Rates in Breast Cancer

Purpose

We evaluated the clinical value of breast magnetic resonance imaging (MRI) in patients who underwent breast-conserving surgery (BCS). The degree of correlation between pathology size and MRI or ultrasonography (US) size was compared based on breast cancer subtypes. In addition, we investigated the positive margin rates.

Methods

Patients with invasive breast cancer who underwent preoperative breast MRI and US between 2011 and 2016 were included in the study. Lin's concordance correlation coefficient was used to measure the correlation between MRI or US andpathologic tumor extent. Tumor extent was defined as pathologic tumor size, including in situ carcinoma. Margin positivity was assessed based on frozen-section examination.

Results

A total of 516 patients with a single tumor who underwent BCS were included in the study. The correlation between pathologic size and MRI was significantly higher than that of US (r = 0.6975 vs. 0.6211, p = 0.001). The superiority of MRI over US in measuring the pathologic extent was only observed in triple-negative breast cancer (TNBC; r = 0.8089 vs. 0.6014, p < 0.001). The agreement between MRI or US and tumor extent was low for the human epidermal growth factor receptor 2 (HER2)-positive subtype (MRI: 0.5243, US: 0.4898). Moreover, the positive margin rate was higher in the HER2-positive subtype than in the others (luminal/HER2-negative: 11.6%, HER2-positive: 23.2%, TNBC: 17.8%, p = 0.019). The post hoc analysis showed that the HER2-positive subtype was more likely to show positive margins than the luminal/HER2-negative subtype (p = 0.007).

Conclusion

Breast MRI was superior to US in the preoperative assessment of the pathologic extent of tumor size; this was most evident in TNBC. For HER2-positive tumors, imaging-pathologic discordance resulted in higher positive margin rates than that with other subtypes.

[Predictive factors of concordance (5mm threshold) between MRI and histological sizes of invasive lobular breast cancer]

OBJECTIVE

The aim of this study was to search for predictive factors of concordance between MRI and histological sizes for invasive lobular breast cancer.

MATERIAL AND METHODS

All women managed for an invasive lobular breast cancer (pure or associated to a component of invasive ductal carcinoma) between 1st january 2007 and 31th december 2016 were included to the study. Univariable and multivariable analysis were performed to determine clinical or histological predictive factors of concordance between MRI and histological sizes for invasive lobular breast cancer (threshold 5mm).

RESULTS

During the study period 384 women were managed in our center for an invasive lobular carcinoma. We had access to the breast MRI of 246 of them. For a concordance witha threshold of 5mm, significant factors in univariate analysis were: menopausal status (OR 1.93[1.01-3.71], P=0.04), histological size (OR 0.97 [0.96-0.99], P<0.0001), lthe size of associated in situ component (OR 0.74 [0.32-1.71], P=0.01), multifocality (OR 0.56 [0.33-0.95] P=0.03) and the histological isolated invasive lobular carcinoma versus mixed ((OR 2.64 [1.01-6.91], P=0.03). In multivariate analysis, menopausal status, histological size and the histological isolated invasive lobular carcinoma versus mixed, were considered as independent predictive factors.

CONCLUSION

This work identified independent predictive factors of concordance between MRI and histological sizes for invasive lobular breast cancer (threshold 5mm).

Role of Magnetic Resonance Imaging in the Preoperative Staging and Work-Up of Patients Affected by Invasive Lobular Carcinoma or Invasive Ductolobular Carcinoma

Purpose

The prevalence of invasive lobular carcinoma (ILC), the second most common type of breast cancer, accounts for 5%-15% of all invasive breast cancer cases. Its histological feature to spread in rows of single cell layers explains why it often fails to form a palpable lesion and the lack of sensitivity of mammography and ultrasound (US) to detect it. It also has a higher incidence of multifocal, multicentric, and contralateral disease when compared to the other histological subtypes. The clinicopathologic features and outcomes of Invasive Ductolobular Carcinoma (IDLC) are very similar to the ILC. The purpose of our study is to assess the importance of MRI in the preoperative management and staging of patients affected by ILC or IDLC.

Materials and Methods

We identified women diagnosed with ILC or IDLC. We selected the patients who had preoperative breast MRI. For each patient we identified the areas of multifocal, multicentric, or contralateral disease not visible to standard exams and detected by preoperative MRI. We analyzed the potential correlation between additional cancer areas and histological cancer markers.

Results

Of the 155 women who met our inclusion criteria, 93 (60%) had additional cancer areas detected by MRI. In 61 women, 39,4% of the overall population, the additional cancer areas were confirmed by US/tomosynthesis second look and biopsy. Presurgical MRI staging changed surgical management in the 37,4% of the patients. Only six patients of the overall population needed a reoperation after the initial surgery. No statistically significant correlation was found between MRI overestimation and the presence of histological peritumoral vascular/linfatic invasion. No statistically significant correlation was found between additional cancer areas and histological cancer markers.

Conclusions

Our study suggests that MRI is an important tool in the preoperative management and staging of patients affected by lobular or ductolobular invasive carcinoma.

Does the use of pretreatment MRI change the management of patients with newly diagnosed breast cancer?

Breast MRI plays a critical role in the diagnosis and management of breast cancer. The purpose of this study is to evaluate the effect of preoperative breast MRI on the management of a large cohort of breast cancer patients at our institution. This study is a retrospective chart review of all newly diagnosed breast cancer patients who underwent preoperative breast MRI at our institution between January 1, 2004 and December 31, 2009. 1352 patients comprised the study population. 241 (17.8%) patients underwent a change in surgical management as a result of preoperative MRI. Patients with tumors in the lower inner quadrant and the central breast and those with pathology of invasive lobular carcinoma were significantly more likely to have their management changed by preoperative MRI. There was also a significant trend for larger tumors to be associated with a change in surgical management. No statistically significant association was found between breast density and change in management. This study supports the recommendation for the use of preoperative breast MRI in the majority of newly diagnosed breast cancer patients, especially those with larger tumors, pathology of invasive lobular carcinoma, and tumors in the lower inner quadrant. Preoperative breast MRI is a useful tool for the evaluation of additional disease that led to a change in the surgical management of 17.8% of patients.

Integrating anatomy, radiology, pathology, and surgery: An alternative approach in resecting multifocal and multicentric breast carcinoma

The sick lobe hypothesis provides the basis for a lobar approach in radiology, pathology, and surgical treatment of breast cancer. This approach aims to remove the tumor together with the surrounding field of genetic aberrations. Detailed preoperative lobar imaging that properly maps the disease and assesses its extent guides the parenchymal resection. Integration of our knowledge of breast anatomy and pathology with the results of preoperative radiological mapping is critical in assessing the eligibility of patients with multifocal and/or multicentric breast cancer for breast conservation treatment. Through an appropriately selected incision, a multisegment resection of the diseased lobe(s) is performed, which leaves the residual parenchyma in a formation that allows dovetailing of one part into the other, like the way pieces of a jigsaw puzzle fit together. Detailed pathologic analysis of the surgical specimen provides valuable feedback to the radiologist, establishes the completeness of surgical intervention, and generates predictive information for therapeutic decisions. Our approach is a step in continuous search for ideal tailored therapy to avoid under or over-treatment of breast cancer patients.

Relevance of breast MRI in determining the size and focality of invasive breast cancer treated by mastectomy: a prospective study

Background

The aim of this study was the evaluation of breast MRI in determining the size and focality of invasive non-metastatic breast cancers.

Methods

The prospective, single-centre study conducted in 2015 compared preoperative MRI with histological analysis of mastectomy.

Results

One hundred one mastectomies from 98 patients were extensively analysed. The rates of false-positive and false-negative MRI were 2 and 4% respectively. The sensitivity of breast MRI was 84.7% for the detection of all invasive foci, 69% for single foci and 65.7% for multiple foci. In the evaluation of tumour size, the Spearman rank correlation coefficient r between the sizes obtained by MRI and histology was 0.62. The MRI-based prediction of a complete response to neoadjuvant chemotherapy was 75%.

Discussion

MRI exhibits high sensitivity in the detection of invasive breast cancers. False positives were linked to the inflammatory nature of the tumour bed. False negatives were associated with small or low-grade tumours and their retro-areolar location. The size of T1 tumours was overestimated by an average of 7%, but MRI was the most efficient procedure. The sensitivity of MRI for the diagnosis of unifocal tumours was higher than that for multifocal sites. Our study confirmed the positive contribution of preoperative MRI for invasive lobular carcinomas and complete response predictions after neoadjuvant chemotherapy.