Breast MRI during Neoadjuvant Chemotherapy: Lack of Background Parenchymal Enhancement Suppression and Inferior Treatment Response.

Background Suppression of background parenchymal enhancement (BPE) is commonly observed after neoadjuvant chemotherapy (NAC) at contrast-enhanced breast MRI. It was hypothesized that nonsuppressed BPE may be associated with inferior response to NAC. Purpose To investigate the relationship between lack of BPE suppression and pathologic response. Materials and Methods A retrospective review was performed for women with menopausal status data who were treated for breast cancer by one of 10 drug arms (standard NAC with or without experimental agents) between May 2010 and November 2016 in the Investigation of Serial Studies to Predict Your Therapeutic Response with Imaging and Molecular Analysis 2, or I-SPY 2 TRIAL (NCT01042379). Patients underwent MRI at four points: before treatment (T0), early treatment (T1), interregimen (T2), and before surgery (T3). BPE was quantitatively measured by using automated fibroglandular tissue segmentation. To test the hypothesis effectively, a subset of examinations with BPE with high-quality segmentation was selected. BPE change from T0 was defined as suppressed or nonsuppressed for each point. The Fisher exact test and the Z tests of proportions with Yates continuity correction were used to examine the relationship between BPE suppression and pathologic complete response (pCR) in hormone receptor (HR)-positive and HR-negative cohorts. Results A total of 3528 MRI scans from 882 patients (mean age, 48 years ± 10 [standard deviation]) were reviewed and the subset of patients with high-quality BPE segmentation was determined (T1, 433 patients; T2, 396 patients; T3, 380 patients). In the HR-positive cohort, an association between lack of BPE suppression and lower pCR rate was detected at T2 (nonsuppressed vs suppressed, 11.8% [six of 51] vs 28.9% [50 of 173]; difference, 17.1% [95% CI: 4.7, 29.5]; P = .02) and T3 (nonsuppressed vs suppressed, 5.3% [two of 38] vs 27.4% [48 of 175]; difference, 22.2% [95% CI: 10.9, 33.5]; P = .003). In the HR-negative cohort, patients with nonsuppressed BPE had lower estimated pCR rate at all points, but the P values for the association were all greater than .05. Conclusions In hormone receptor-positive breast cancer, lack of background parenchymal enhancement suppression may indicate inferior treatment response. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Philpotts in this issue.

Contrast-Enhanced Mammography for Newly Diagnosed Breast Cancer in Women With Breast Augmentation: Preliminary Findings.

In 17 women with newly diagnosed breast cancer who underwent contrast-enhanced mammography (CEM) and MRI, both modalities were found to be concordant for the index cancer. In six of the 17 women, CEM showed an additional lesion that was confirmed by MRI. Of these six additional lesions, three were multifocal, one was multicentric, and two were contralateral; two of the six were malignant. MRI did not identify any additional cancers that were not identified on CEM. CEM may have a role in women with breast augmentation and either a contraindication or limited access to MRI.

Initial Experience of Tomosynthesis-Guided Vacuum-Assisted Biopsies of Tomosynthesis-Detected (2D Mammography and Ultrasound Occult) Architectural Distortions.

OBJECTIVE: As experience and aptitude in digital breast tomosynthesis (DBT) have increased, radiologists are seeing more areas of architectural distortion (AD) on DBT images compared with standard 2D mammograms. The purpose of this study is to report our experience using tomosynthesis-guided vacuum-assisted biopsies (VABs) for ADs that were occult at 2D mammography and ultrasound and to analyze the positive predictive value for malignancy. MATERIALS AND METHODS: We performed a retrospective review of 34 DBT-detected ADs that were occult at mammography and ultrasound. RESULTS: We found a positive predictive value of 26% (nine malignancies in 34 lesions). Eight of the malignancies were invasive and one was ductal carcinoma in situ. The invasive cancers were grade 1 (4/8; 50%), grade 2 (2/8; 25%), or grade 3 (1/8; 13%); information about one invasive cancer was not available. The mean size of the invasive cancers at pathologic examination was 7.5 mm (range, 6-30 mm). CONCLUSION: Tomosynthesis-guided VAB is a feasible method to sample ADs that are occult at 2D mammography and ultrasound. Tomosynthesis-guided VAB is a minimally invasive method that detected a significant number of carcinomas, most of which were grade 1 cancers. Further studies are needed.

Contrast-enhanced Digital Mammography: A Single-Institution Experience of the First 208 Cases.

Contrast-enhanced digital mammography (CEDM) is the only imaging modality that provides both (a) a high-resolution, low-energy image comparable to that of digital mammography and (b) a contrast-enhanced image similar to that of magnetic resonance imaging. We report the initial 208 CEDM examinations performed for various clinical indications and provide illustrative case examples. Given its success in recent studies and our experience of CEDM primarily as a diagnostic adjunct, CEDM can potentially improve breast cancer detection by combining the low-cost conclusions of screening mammography with the high sensitivity of magnetic resonance imaging.

Clinical and self breast examination remain important in the era of modern screening.

BACKGROUND: Breast cancer screening recommendations are in flux. We reviewed the methods of detecting newly diagnosed breast neoplasms at our institution. METHODS: A retrospective review of patients stratified by age was performed to compare mammography with self- (SBE) and clinical (CBE) breast examination methods of cancer detection from 2005 to 2009. RESULTS: We identified 782 patients. Patients aged <50 years were more likely to present with palpable disease (P < 0.001). Overall, 75% of patients had a mammogram within 24 months. There was a higher incidence of Tis tumors and lower incidence of T1 tumors if patients had mammography performed within 12 months versus 13-24 months (P < 0.01); tumor size, hormonal status, and lymph node (LN) status were comparable between these two groups. Patients diagnosed by SBE/CBE who had mammography performed within 12 months versus 13-24 months did not differ statistically according to tumor characteristics. In the screened cohort (mammography within 24 months), the majority of patients (64%) were diagnosed by mammography. Cancers detected by SBE/CBE were larger tumors (2.4 vs. 1.3 cm), higher grade, more frequently ER- (29 vs. 16%), triple-negative (21 vs. 10%), and lymph node-positive (39 vs. 18%; all P ≤ 0.01). There were no statistically significant differences in tumor size, T stage, or hormonal status in patients who had analog versus digital mammography. CONCLUSIONS: Whereas the majority of patients had image-detected breast cancer, a significant number of image-screened patients presented with palpable disease, which were more aggressive cancers. Until imaging techniques are refined, SBE and CBE remain important for breast cancer diagnosis.

Atypical ductal hyperplasia on core biopsy: an automatic trigger for excisional biopsy?

INTRODUCTION: Excisional biopsy is currently recommended for atypical ductal hyperplasia (ADH) diagnosed on core needle breast biopsy (CNB), due to risk of upstaging to invasive or in situ carcinoma (DCIS). The study goal was to identify patients who may potentially forego excisional biopsy if the risk of upstaging is low. METHODS: We conducted a retrospective review of patients diagnosed with ADH on CNB who underwent excisional biopsy at one institution (5/2000-5/2011). We evaluated the upstaging rate and clinicopathologic factors associated with increased upstaging risk. RESULTS: A total of 114 cases of ADH were diagnosed on CNB. The median patient age was 64 years. On mammography, a mass/density/area of distortion was present in 23 % of cases; calcifications were present in 77 %. Most biopsies (79 %) were performed stereotactically. Twenty lesions (18 %) were upstaged to infiltrating carcinoma (5 %) or DCIS (13 %). Residual ADH was present in 43 biopsies (38 %). On univariate analysis, significant variables associated with upstaging included age >50 years, a mass lesion on mammography, and shorter length of biopsy core (p < 0.05). No patient ≤50 years of age was upstaged. Three patients who were not upstaged (3 %) developed ipsilateral disease (2 DCIS and 1 infiltrating ductal carcinoma) at a median time of 37 months. CONCLUSIONS: The rate of upstaging when ADH is diagnosed on CNB at our institution is 18 %, and routine excisional biopsy is currently recommended for all patients. However, patients <50 years old with focal atypia only and no residual calcifications postbiopsy may represent a low-risk group who could potentially avoid excisional biopsy.

Contrast Enhanced Mammography in Routine Clinical Practice: Frequency and Malignancy Rates of Enhancing Otherwise Occult Findings.

BACKGROUND: In routine clinical practice, contrast-enhanced mammography (CEM) examinations identify enhancing findings seen only on subtraction images that have no low-energy mammographic or sonographic correlate. The purpose of this study is to report the frequency and malignancy rates of enhancing findings seen only on subtraction images in a tertiary care breast imaging practice. MATERIALS AND METHODS: Consecutive review of CEM exams from December 2015 to May 2020. Chi square tests were used to determine associations between cancer diagnosis and clinical characteristics of enhancing findings seen only on subtraction images, P < .05 indicating a statistically significant difference. RESULTS: Four percent (100/2464) of CEM examinations identified 108 enhancing findings seen only on subtraction images. Twenty of those CEM enhancing findings were directly managed as a multifocal disease. Of those further evaluated with MR, 23% (19/78) with associated MR correlates were treated surgically as presumed multicentric or multifocal disease following multidisciplinary review. The remaining 76% (59/78) of enhancing findings were seen only on subtraction images, these included: 20% (12/59) and downgraded to benign on MR 80% (47/59) with suspicious findings which underwent MR vacuum assisted breast biopsy yielding: 26% (12/47) malignancy, 9% (4/47) high risk, and 66% (31/47) benign diagnoses. CONCLUSION: Enhancing findings seen on subtraction only CEM images are seen in 4% of cases in clinical practice. MR correlation can help characterize CEM findings to: (1) avoid unnecessary biopsy for benign findings, and (2) guide tissue sampling or empiric surgical planning for suspicious findings.

Radioactive seed localization for nonpalpable breast lesions: review of 1,000 consecutive procedures at a single institution.

INTRODUCTION: Radioactive seed localization (RSL) is an alternative to wire localization for nonpalpable breast lesions, with reported lower rates of positive surgical margins. METHODS: A retrospective review of all consecutive RSL procedures performed at a single institution from 01/2003 through 10/2010 was conducted. RESULTS: One thousand RSL breast procedures were performed in 978 patients. Indications for RSL included invasive carcinoma (52%), in situ carcinoma (22%), atypical hyperplasia (11%), and suspicious percutaneous biopsy findings (15%). A total of 1,148 seeds were deployed using image guidance, with 76% placed ≥1 day before surgery. Most procedures (86%) utilized one seed. A negative margin was achieved at the first operation in 97% of patients with invasive carcinoma and 97% of patients with ductal carcinoma in situ (DCIS). An additional 9% of patients with invasive carcinoma and 19% of patients with DCIS had close (≤2 mm) margins, and underwent re-excision. Sentinel lymph node biopsy was successfully performed in 99.8% of cases. Adverse events included 3 seeds (0.3%) not deployed correctly on first attempt and 30 seeds (2.6%) displaced from the breast specimen during excision of the targeted lesion. All seeds were successfully retrieved, with no radiation safety concerns. Local recurrence rates were 0.9% for invasive breast cancer and 3% for DCIS after mean follow-up of 33 months. There was no evidence of a learning curve. CONCLUSIONS: RSL is a safe, effective procedure that is easy to learn, with a low incidence of positive/close margins. RSL should be considered as the method of choice for localization of nonpalpable breast lesions.

Use of preoperative magnetic resonance imaging for invasive lobular cancer: good, better, but maybe not the best?

BACKGROUND: Invasive lobular cancer (ILC) of the breast is difficult to diagnose clinically and radiologically. It is hoped that preoperative magnetic resonance imaging (MRI) can improve evaluation of extent of disease. METHODS: Patients diagnosed with ILC at a single institution from 2001 to 2008 who underwent clinical breast examination (CBE), mammography, ultrasound, and MRI were studied retrospectively. Concordance between tumor size on imaging/CBE and pathologic size was defined as size within ± 0.5 cm. Pearson correlation coefficients (R) were calculated for each modality. Local recurrence and re-excision rates were compared with those patients with ILC who did not undergo preoperative MRI. RESULTS: Seventy patients with ILC had all imaging modalities, including CBE, performed preoperatively. The sensitivity for detection of ILC by MRI was 99%. MRI-based tumor size was concordant with pathologic tumor size in 56% of tumors. MRI overestimated tumor size by >0.5 cm in 31% of tumors. Correlation of tumor size on imaging with final pathology was better for MRI (R = 0.75) than for mammography (R = 0.65), CBE (R = 0.63), or ultrasound (R = 0.45, all P < 0.01). Preoperative MRI was associated with lower reoperation rates for close/positive margins (P > 0.05). CONCLUSIONS: For ILC, MRI has better sensitivity of detection and correlation with tumor size at pathology than CBE, mammography, or ultrasound. However, 31% of cases are overestimated by MRI, and correlation remains only at 0.75. The select use of MRI for preoperative estimation of tumor size in ILC is supported by our data, but the need for improvement and refinement of imaging remains.

Role of imaging in breast cancer detection.

This article reviews the role of imaging (i.e., mammography, ultrasound, magnetic resonance imaging) in breast cancer detection. Screening and diagnostic indications are outlined for each modality. New mammography screening guidelines are discussed, and risk factors for breast cancer are included.

Predicting breast cancer response to neoadjuvant treatment using multi-feature MRI: results from the I-SPY 2 TRIAL.

Dynamic contrast-enhanced (DCE) MRI provides both morphological and functional information regarding breast tumor response to neoadjuvant chemotherapy (NAC). The purpose of this retrospective study is to test if prediction models combining multiple MRI features outperform models with single features. Four features were quantitatively calculated in each MRI exam: functional tumor volume, longest diameter, sphericity, and contralateral background parenchymal enhancement. Logistic regression analysis was used to study the relationship between MRI variables and pathologic complete response (pCR). Predictive performance was estimated using the area under the receiver operating characteristic curve (AUC). The full cohort was stratified by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status (positive or negative). A total of 384 patients (median age: 49 y/o) were included. Results showed analysis with combined features achieved higher AUCs than analysis with any feature alone. AUCs estimated for the combined versus highest AUCs among single features were 0.81 (95% confidence interval [CI]: 0.76, 0.86) versus 0.79 (95% CI: 0.73, 0.85) in the full cohort, 0.83 (95% CI: 0.77, 0.92) versus 0.73 (95% CI: 0.61, 0.84) in HR-positive/HER2-negative, 0.88 (95% CI: 0.79, 0.97) versus 0.78 (95% CI: 0.63, 0.89) in HR-positive/HER2-positive, 0.83 (95% CI not available) versus 0.75 (95% CI: 0.46, 0.81) in HR-negative/HER2-positive, and 0.82 (95% CI: 0.74, 0.91) versus 0.75 (95% CI: 0.64, 0.83) in triple negatives. Multi-feature MRI analysis improved pCR prediction over analysis of any individual feature that we examined. Additionally, the improvements in prediction were more notable when analysis was conducted according to cancer subtype.

Operative outcomes of conventional specimen radiography versus in-operating room specimen radiography in radioactive seed-localized segmental mastectomies.

INTRODUCTION: In-operating room specimen radiography (ORSR) has not been studied among women undergoing radioactive seed localization (RSL) for breast cancer surgery and had the potential to decrease operative time and perhaps improve intraoperative margin management. METHODS: One hundred consecutive RSL segmental mastectomies among 98 patients using ORSR were compared to 100 consecutive segmental mastectomies among 98 patients utilizing conventional radiography (CSR) prior to the initiation of ORSR from December 2013 to January 2015 after radioactive seed localization. Final pathologic margins were considered to be 10 mm for all cases of no residual disease after biopsy or neoadjuvant therapy, but such patients were excluded from analyses involving tumor size. All patients' specimens were subjected to intraoperative pathologic consultation in addition to ORSR or CSR. RESULTS: The median age of the cohort was 65 years (range 36-97), and the median tumor size was 1 cm. There were no differences between the ORSR and CSR groups in age, tumor size, percentage of cases with only DCIS, and percentage of cases with microcalcifications. The ORSR group had a statistically significant lower BMI. Mean operative time from cut-to-close was not significantly different (ORSR 77 min, SD 24.8 vs CSR 76 min, SD 24.8, p = 0.75). There was no statistical difference in mean closest final pathologic margin (4.99 mm, SD 3.3 vs 4.88 mm, SD 3.5, p = 0.9). The percentage undergoing intraoperative margin re-excision (ORSR 40%, CR 47%, p = 0.31) and the mean total number of margins excised intraoperatively (ORSR 0.9, CR 1.0 p = 0.65) were similar. The rate of any margin <2 mm was 14% vs 12% for ORSR and CR, respectively (p = 0.64). The mean specimen volume for ORSR was 76cm3 (SD 101.8) vs 90cm3 (SD 61.2) for CSR; this difference was not statistically significant (p = 0.25). The mean ratio of segmental mastectomy volume to maximum tumor diameter was less for ORSR (82.7cm2 vs 139.4cm2, p = 0.014). CONCLUSION: ORSR for RSL breast surgery, in the setting of routine intraoperative pathology consultation, does not significantly impact operative time, the rate or number of additional intraoperative margins excised, the number of reoperations for margins, or the width of final pathological margins. ORSR was associated with a decrease in the volume of segmental mastectomies relative to the tumor diameter.

Validation study of a modern treatment algorithm for nipple discharge.

BACKGROUND: Nipple discharge occurs in 2% to 5% of women. We evaluated the effectiveness of a previously proposed treatment algorithm for these patients. METHODS: Patients with pathologic nipple discharge and a negative mammogram and subareolar ultrasound were offered follow-up from 2005 to 2011 according to the algorithm. RESULTS: A total of 192 patients, mean age 56 years, were studied. Risk of carcinoma among the entire cohort was 5%. Breast surgeon was consulted for 142 (74%) patients: 48 (34%) underwent initial subareolar excision and 94 (66%) were clinically followed. The rate of carcinoma was 17% (8/48) after initial subareolar excision, 0% (0/13) for those without imaging abnormalities, 23% (8/35) with imaging abnormalities, and 1% (1/94) with clinical follow-up. Of patients who underwent follow-up, 21% (n = 20) underwent subareolar excision because of imaging abnormality (n = 1, 1%) or persistent discharge (n = 19, 20%). Most patients had ductal carcinoma in situ (n = 5, 56%). CONCLUSIONS: Patients with nipple discharge can be prospectively identified based on radiographic findings and clinical examination for safe clinical follow-up. Most will have resolution avoiding a surgical procedure.

Papillary lesions on core breast biopsy: excisional biopsy for all patients?

Excisional biopsy has been recommended for papillary lesions diagnosed on core needle biopsy (CNB) because a significant proportion of cases are upstaged to in situ/invasive cancer after surgical excision. The study goals were to identify patients at lowest risk of upstaging in whom excisional biopsy may potentially be avoided. We retrospectively evaluated 46 patients with a papillary lesion on CNB. Six patients were upstaged overall (13%), to intraductal papillary carcinoma (7%), invasive papillary carcinoma (4%), and mixed invasive ductal/lobular carcinoma (2%). The upstaging rate for patients with atypia on CNB was higher than for patients without atypia (33 vs 3%, P = 0.011). No patient younger than 65 years was upstaged to in situ or invasive carcinoma, and the mean lesion size was also higher among patients who were upstaged (P > 0.05). Patients younger than 65 years with small papillary lesions lacking atypia on CNB may therefore represent a low-risk group that may be offered close clinical and radiologic follow-up.

Is there concordance of invasive breast cancer pathologic tumor size with magnetic resonance imaging?

BACKGROUND: In the era of breast conservation therapy, preoperative imaging is imperative in planning a single definitive surgical treatment. METHODS: We performed a retrospective review of a prospectively collected database of patients treated at a single institution for invasive breast cancer over 5 years. Clinical and pathologic variables were analyzed with respect to magnetic resonance imaging (MRI) and pathologic tumor size using analysis of variance F tests and chi-square tests. RESULTS: Of 190 patients, 53% had concordance of MRI and pathologic cancer size within .5 cm. MRI overestimated 33% and underestimated 15% of tumors. Neoadjuvant chemotherapy and lymph node status were associated with discordance. Among tumors overestimated by MRI, 65% had additional significant findings in the breast tissue around the main lesion: satellite lesions, ductal carcinoma in situ, and/or lymphovascular invasion. CONCLUSIONS: Breast MRI is concordant with pathologic tumor size within .5 cm among 53% of patients. Most patients with tumors overestimated by MRI have significant findings in the surrounding breast tissue, the excision of which would be expected to benefit the patient.

Scientific Presentation Award: The impact of magnetic resonance imaging on surgical treatment of invasive breast cancer.

BACKGROUND: The purpose of this study was to examine the relationship between magnetic resonance imaging (MRI) and surgical treatment of invasive breast cancer (IBC). METHOD: The IBC patients treated from January 2003-June 2008 were reviewed by a single institution. RESULTS: A total of 814 patients were treated, out of which 562 (69%) underwent breast conservation therapy (BCT), 151 (19%) chose mastectomy alone (M), and 101 (12%) chose mastectomy with reconstruction (M+ R). The mean age was comparatively low in M + R patients (P

Does magnetic resonance imaging accurately predict residual disease in breast cancer?

BACKGROUND: The accuracy of magnetic resonance imaging (MRI) in identifying residual disease after breast conservation therapy (BCT) is unclear. METHOD: Review of an institutional database identified patients with positive or close (