Can preoperative 3-T MRI predict nipple–areolar complex involvement in patients with breast cancer?

A Nomogram Based on Conventional and Contrast-Enhanced Ultrasound for Pre-operative Prediction of Nipple-Areola Complex Involvement in Breast Cancer: A Prospective Study

OBJECTIVE

Accurately predicting nipple-areola complex (NAC) involvement in breast cancer is essential for identifying eligible patients for a nipple-sparing mastectomy. This study was aimed at developing a pre-operative nomogram for NAC involvement in breast cancer using conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS).

METHODS

All patients with primary breast cancer confirmed by pre-operative biopsy underwent US and CEUS examinations. Post-operative pathology was used as the gold standard in assessing NAC involvement. Lasso regression was used to select the predictors most associated with NAC involvement. A nomogram was constructed to calculate the diagnostic efficacy. The data were internally verified with 500 bootstrapped replications, and a calibration curve was generated to validate the predictive capability.

RESULTS

Seventy-six patients with primary breast cancer were included in this study, which included 16 patients (21.1%) with NAC involvement and 60 patients (78.9%) without NAC involvement. Among the 23 features of US and CEUS, Lasso regression selected one US feature and two CEUS features, namely, ductal echo extending from the lesion, ductal enhancement extending to the nipple and focal nipple enhancement. A nomogram was constructed, and the results revealed that the area under the curve, sensitivity, specificity and accuracy were 0.891, 81.3%, 86.7% and 85.5%, respectively. The calibration curve exhibited good consistency between the predicted probability and the actual probability.

CONCLUSION

The nomogram developed based on US and CEUS had good performance in predicting NAC involvement in breast cancer before surgery, which may facilitate the selection of suitable patients for NAC preservation with greater oncological safety.

Intraoperative Examination of Retro-Areolar Margin is not Routinely Necessary During Nipple-Sparing Mastectomy for Cancer

BACKGROUND

Intraoperative examination of retro-areolar margin (IERM) often is used during nipple-sparing mastectomy (NSM) for cancer, but there is no robust data regarding its real advantage.

METHODS

Consecutive patients undergoing NSM for cancer with omission of IERM according to institutional protocols from 2016 to 2021 were retrospectively analyzed. The decision to maintain or remove the Nipple-Areola Complex (NAC) after definitive pathology was taken at the multidisciplinary meeting.

RESULTS

Among 162 women operated in the study period, the presence of neoplastic cells within 2 mm from the inked retroareolar margin (RAM) was detected at permanent pathology in 17 cases (10.5%). Nipple-Areola-Complex (NAC) was removed postoperatively in five patients (3%) for margins <1 mm, the other 12 were observed, whereas postoperative NAC necrosis required surgical removal in additional five cases (3%). The NAC was thus preserved in 152 of 162 patients (94%). At multivariate analysis, RAM ≤2 mm was associated with radiological tumor-to-nipple distance less than or equal to 1 cm (p = 0.04) and Ki67 label index ≥ 20 (p = 0.04), whereas multifocality/multicentricity showed a trend towards significance (p = 0.07). At a median follow-up of 46 months, five locoregional relapses occurred (3%), only one of them involving the NAC (0, 6%). Locoregional relapse and overall survival for patients with RAM > or < 2 mm were not different.

CONCLUSIONS

IERM is not routinely necessary during NSM for cancer, because its omission is associated with a very low return to the operating room, it is oncologically safe, and associated pitfalls are avoided. Further studies are necessary to confirm these findings.

Diagnostic Accuracy of Magnetic Resonance Imaging Features and Tumor-to-Nipple Distance for the Nipple-Areolar Complex Involvement of Breast Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review and meta-analysis evaluated the accuracy of preoperative breast magnetic resonance imaging (MRI) features and tumor-to-nipple distance (TND) for diagnosing occult nipple-areolar complex (NAC) involvement in breast cancer.

MATERIALS AND METHODS

The MEDLINE, Embase, and Cochrane databases were searched for articles published until March 20, 2022, excluding studies of patients with clinically evident NAC involvement or those treated with neoadjuvant chemotherapy. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Two reviewers independently evaluated studies that reported the diagnostic performance of MRI imaging features such as continuity to the NAC, unilateral NAC enhancement, non-mass enhancement (NME) type, mass size (> 20 mm), and TND. Summary estimates of the sensitivity and specificity curves and the summary receiver operating characteristic (SROC) curve of the MRI features for NAC involvement were calculated using random-effects models. We also calculated the TND cutoffs required to achieve predetermined specificity values.

RESULTS

Fifteen studies (n = 4002 breast lesions) were analyzed. The pooled sensitivity and specificity (with 95% confidence intervals) for NAC involvement diagnosis were 71% (58-81) and 94% (91-96), respectively, for continuity to the NAC; 58% (45-70) and 97% (95-99), respectively, for unilateral NAC enhancement; 55% (46-64) and 83% (75-88), respectively, for NME type; and 88% (68-96) and 58% (40-75), respectively, for mass size (> 20 mm). TND had an area under the SROC curve of 0.799 for NAC involvement. A TND of 11.5 mm achieved a predetermined specificity of 85% with a sensitivity of 64%, and a TND of 12.3 mm yielded a predetermined specificity of 83% with a sensitivity of 65%.

CONCLUSION

Continuity to the NAC and unilateral NAC enhancement may help predict occult NAC involvement in breast cancer. To achieve the desired diagnostic performance with TND, a suitable cutoff value should be considered.

MRI Breast: Current Imaging Trends, Clinical Applications, and Future Research Directions

Magnetic Resonance Imaging (MRI) is the most sensitive and advanced imaging technique in diagnosing breast cancer and is essential in improving cancer detection, lesion characterization, and determining therapy response. In addition to the dynamic contrast-enhanced (DCE) technique, functional techniques such as magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI), diffusion kurtosis imaging (DKI), and intravoxel incoherent motion (IVIM) further characterize and differentiate benign and malignant lesions thus, improving diagnostic accuracy. There is now an increasing clinical usage of MRI breast, including screening in high risk and supplementary screening tools in average-risk patients. MRI is becoming imperative in assisting breast surgeons in planning breast-conserving surgery for preoperative local staging and evaluation of neoadjuvant chemotherapy response. Other clinical applications for MRI breast include occult breast cancer detection, investigation of nipple discharge, and breast implant assessment. There is now an abundance of research publications on MRI Breast with several areas that still remain to be explored. This review gives a comprehensive overview of the clinical trends of MRI breast with emphasis on imaging features and interpretation using conventional and advanced techniques. In addition, future research areas in MRI breast include developing techniques to make MRI more accessible and costeffective for screening. The abbreviated MRI breast procedure and an area of focused research in the enhancement of radiologists' work with artificial intelligence have high impact for the future in MRI Breast.

Nipple-sparing Mastectomy: What the Radiologist Should Know

Nipple-sparing mastectomy (NSM) is increasingly offered to patients undergoing treatment of breast cancer and prophylaxis treatment for reduction of breast cancer risk. NSM is considered oncologically safe for appropriately selected patients and is associated with improved cosmetic outcomes and quality of life. Accepted indications for NSM have expanded in recent years, and currently only inflammatory breast cancer or malignancy involving the nipple is considered an absolute contraindication. Neoplasms close to and involving the nipple areolar complex are common, and cancer of the lactiferous ducts can spread to the nipple. Therefore, accurate determination of nipple involvement at imaging examinations is critical to identifying appropriate candidates for NSM and preventing local recurrence. Multiple imaging features have been described as predictors of nipple involvement, with tumor to nipple distance, enhancement between the index malignancy and the nipple, and nipple retraction demonstrating the highest predictive values. These features can be assessed at multimodality breast imaging, particularly at breast MRI, which demonstrates high specificity and negative predictive value for determining nipple involvement in malignancy. Online supplemental material is available for this article. ^©RSNA, 2022.

Prediction of nipple-areolar complex involvement by breast cancer: role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)

Background

Skin-sparing and nipple-sparing mastectomies were considered as alternative techniques for modified radical mastectomy. In patients who are candidates for nipple-sparing mastectomy, preoperative assessment of the nipple-areolar complex (NAC) is essential for adequate surgical planning. Breast MRI is highly sensitive for cancer detection and has an important role in disease staging. The aim of this study was to estimate the role of DCE-MRI in predicting malignant NAC invasion by underlying breast cancer and assess the best predictors on MRI that can suspect malignant NAC invasion.

Results

Out of the 125 patients with breast cancer, 33 patients (26.4%) showed malignant NAC invasion. On basis of multivariate analysis, abnormal nipple enhancement, tumor nipple enhancement, tumor nipple distance ≤ 2 cm, and abnormal and asymmetric nipple morphology were all significant predictors of malignant NAC invasion (P < 0.001) with abnormal unilateral nipple enhancement as the most important independent MRI predictor of malignant NAC invasion (odds ratio = 61.07, 95% CI 12.81–291.22, P < 0.001). When combining more than positive suspicious MRI features, DCE-MRI had 66.6% sensitivity, 76% specificity, 50% PPV, 86.4% NPV, and 73.6% accuracy in prediction of malignant NAC invasion.

Conclusion

DCE-MRI could predict malignant NAC invasion with abnormal unilateral nipple enhancement as the most important independent MRI predictor.

Comparison of the Magnetic Resonance Imaging Findings of Paget's Disease of the Breast and Malignant Tumor Invasion of the Nipple-Areola Complex

Objective

We aimed to investigate the distinction between Paget's disease of the breast (PDB) and malignant tumor invasion of nipple-areolar complex (MTION) with Magnetic resonance imaging (MRI) findings without the need for skin punch biopsy.

Materials and Methods

MRI findings of 16 patients with pathologically proven PDB and 11 patients with pathologically proven MTION were reviewed retrospectively. MRI images were assessed for nipple morphological changes; areolar-periareolar skin changes; thickness, classification, and kinetic characteristics of the nipple-areolar complex (NAC) enhancement; morphological pattern, size, and pathological diagnosis of concomitant malignant lesions; kinetic characteristics of the concomitant malignant lesions enhancement; continuity of enhancement between the nipple and closest concomitant malignant lesion; similarity of enhancement kinetics of the NAC and concomitant malignant lesions; and nipple-to-malignant lesion distance in both patient groups.

Results

Areolar-periareolar skin thickening was statistically different between the patient groups. Enhancement kinetic pattern was classified as persistent in four patients with MTION and plateau in seven patients with PDB. Moreover, NAC enhancement kinetic characteristics were statistically different between the groups. Invasive ductal carcinoma was detected in three patients with PDB and five patients with MTION. A statistically significant difference in malignant lesion pathological types was detected between the patient groups.

Conclusion

The significant MRI findings in patients with MTION diagnosed as invasive ductal carcinoma were areolar-periareolar skin thickening and asymmetric NAC enhancement with persistent kinetics pattern. In patients diagnosed with ductal carcinoma in situ, a plateau pattern of asymmetric NAC enhancement without any areolar-periareolar skin changes on MRI may indicate PDB.

MIP image derived from abbreviated breast MRI: potential to reduce unnecessary sub-nipple biopsies during nipple-sparing mastectomy for breast cancer

OBJECTIVE

To determine the value of a maximum-intensity projection (MIP) image derived from abbreviated breast MRI for excluding occult nipple-areolar complex (NAC) involvement in patients with breast cancer.

METHODS

This prospective study included breast cancer patients with clinically normal NACs between April 2016 and May 2019. Abbreviated breast MRI was performed, and an MIP image was generated for each patient. MIP images were examined for the following features: asymmetric nipple enhancement, tumor-nipple distance (TND), tumor diameter, lesion type, location, and multifocality. Independent predictive MIP features for occult NAC involvement were identified by univariable and multivariable logistic regression analyses. Models based on independent predictive MIP features were developed, and their diagnostic performances were evaluated using ROC analysis. The utility of an MIP image for excluding occult NAC involvement was assessed by considering NPVs across patient subgroups.

RESULTS

Eight hundred forty-three patients (67 NAC-positive and 776 NAC-negative) were enrolled. On MIP images, asymmetric nipple enhancement (odds ratio, 6.098; p < 0.001) and TND (odds ratio, 0.564; p = 0.003) were independent predictors of occult NAC involvement. A parallel test model of "asymmetric nipple enhancement or TND ≤ 15 mm" yielded the highest AUC value (0.838) among prediction models. The NPV of MIP images for excluding occult NAC involvement was 99.5%, which was applicable across various patient subgroups.

CONCLUSIONS

A single MIP image derived from abbreviated breast MRI has utility for excluding occult NAC involvement in breast cancer patients and reducing the number of unnecessary sub-nipple biopsies in nipple-sparing mastectomy.

KEY POINTS

• On MIP images derived from abbreviated breast MRI, asymmetric nipple enhancement and tumor-nipple distance were independent predictors for occult nipple involvement in patients with breast cancer. • Negative findings on MIP image can help select patients at minimal risk of occult nipple involvement, for whom unnecessary intraoperative sub-nipple biopsies in nipple-sparing mastectomy can be omitted.

A novel MRI-based predictive index can identify patients suitable for preservation of the nipple-areola complex in breast reconstructive surgery

INTRODUCTION

Accurately predicting nipple-areola complex (NAC) involvement in breast cancer is necessary for identifying patients who may be candidates for a nipple-sparing mastectomy. Although multiple risk factors are indicated in the guidelines, it is difficult to predict NAC involvement (NAC-i) preoperatively even if these factors are evaluated individually. This study aimed to develop a more accurate and practical preoperative NAC-i prediction model using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

All tumors in 252 patients were evaluated using postcontrast T1-weighted subtraction on MRI.

RESULTS

The receiver operating characteristic curves identified cut-off values for tumor size and tumor-to-nipple distance (TND) as 4 cm and 1.2 cm, respectively. Multivariate analysis demonstrated that TND (p < 0.001), ductal enhancement extending to the nipple (DEEN) (p < 0.001), and nipple enhancement (NE) (p = 0.005) were independent clinical risk factors for pathological NAC-i. A formula was constructed using odds ratios for these three independent preoperative risk factors in multivariate analysis: the MRI-based NAC-i predictive index (mNACPI) = TND × 4 + DEEN × 3 + NE × 1. A total score of ≤4 points was defined as low risk and ≥5 points as high risk. NAC-i rates were 2.4% in the low-risk group and 89.4% in the high-risk group; a significant correlation was observed between the risk group and permanent pathological NAC-i (p < 0.001). Assuming that the NAC was preserved in low-risk patients and resected in high-risk patients, NAC-i was verified using the mNACPI.

CONCLUSION

mNACPI may contribute greatly to the improvement of selecting suitable patients for NAC preservation in breast reconstructive surgery while maintaining oncological safety.

Role of diffusion-weighted imaging in prediction of nipple-areolar complex invasion by breast cancer

THE AIM OF THIS WORK

The aim of this work was to estimate the role of diffusion-weighted imaging (DWI) in predicting malignant invasion of the nipple-areolar complex (NAC) by underlying breast cancer.

MATERIAL AND METHODS

This prospective study included 70 female patients with breast cancer with a mean age of 45.8 years (range: 28-68). DWI of the breast was done for all patients. Apparent diffusion coefficient (ADC) maps were automatically constructed. The mean ADC values of NAC were independently measured by two observers who are experts in breast imaging and correlated with the results of histopathological examinations.

RESULTS

Both observers found a significantly lower ADC value of malignant NAC invasion (n = 18) when compared with free NAC (n = 52), with mean ADC value for malignant NAC invasion was 0.86 ± 0.35 × 10^-3 mm²/s and 0.84 ± 0.08 × 10^-3 mm²/s for observer one and two respectively versus mean ADC value of 1.34 ± 0.25 × 10^-3 mm²/s and 1.4 ± 0.26 × 10^-3 mm²/s for free NAC by observer one and two respectively (P-value =0.001). Observer one found that a cutoff ADC value of 1.05 × 0^-3 mm²/s can predict malignant NAC invasion with 0.975 AUC, 92.8% accuracy, 94.4% sensitivity, and 92.3% specificity. Observer two found that a cutoff ADC value of 0.95 × 10^-3 mm²/s can predict malignant NAC invasion with 0.992 AUC, 95.7% accuracy, 88.9% sensitivity, and 98.1% specificity.

CONCLUSION

DWI can predict malignant NAC invasion in patients with breast cancer.

Use of preoperative mammography, ultrasonography, and MRI to predict nipple areolar complex involvement in breast cancer

OBJECTIVE

To identify the predictive factors of cancer invading into the nipple.

METHODS

Patients with breast cancer undergoing mastectomy between May 2009 and March 2019 were reviewed retrospectively. Of these, those with breast cancer within 2 cm of the nipple areolar complex on ultrasonography were included in this study. Clinicopathological data of the primary tumor and imaging findings from mammography, ultrasonography, and MRI were compared between cases with and without nipple involvement by cancer.

RESULTS

In total, 156 of the 821 patients identified were included in the analysis. Of them, 29 had nipple involvement by cancer. Univariate analysis revealed that the following imaging results were significantly associated with nipple involvement: perineural invasion, lymphovascular invasion, lymph node metastasis; relation type between the tumor and the nipple on ultrasonography; periareolar skin thickening on mammography; and short tumor-nipple distance, continuous enhancement between the nipple and tumor, skin enhancement, and nipple enhancement on MRI. However, on multivariate logistic regression analysis, only invasion type of tumor on ultrasonography and nipple enhancement and short tumor-nipple distance on MRI were significantly correlated with nipple involvement by cancer.

CONCLUSION

Imaging findings on preoperative mammography, ultrasonography and MRI are effective predictors for nipple involvement by cancer.

ADVANCES IN KNOWLEDGE

Preoperative mammography, ultrasonography, and MRI help predict nipple involvement by breast cancer.

Clinical value of delayed 18F-FDG PET/CT for predicting nipple-areolar complex involvement in breast cancer: A comparison with clinical symptoms and breast MRI

Objective

We aimed to evaluate the predictive value of delayed ¹⁸F-FDG PET/CT for identifying malignancies involved in the nipple-areolar complex (NAC) in comparison with clinical symptoms and breast MRI.

Methods

We enrolled 90 patients who underwent preoperative delayed ¹⁸F-FDG PET/CT and MRI between October 2015 and May 2017. We calculated the NAC-Standardized uptake value ratio (SUVR) using the following formula: maximum SUV (SUV_max) of the NAC in the malignant breast /SUV_max of the NAC in the contralateral normal breast on early (NAC-SUVR_early) and delayed (NAC-SUVR_delay) phase images. MRI was used to measure the distance between the tumor and NAC and to analyze NAC enhancement patterns. Univariate and multivariate analyses were performed to identify significant predictive factors for NAC involvement.

Results

Seventeen patients were confirmed to have pathologic NAC involvement. NAC symptoms (p = 0.009), tumor multiplicity (p = 0.006), NAC-SUVR_delay (> 1.23, p = 0.007), and MRI-based tumor-to-NAC distance (≤ 22.0 mm, p = 0.003) were independent predictive factors for NAC involvement. Ten of 76 patients with no clinical NAC symptoms had NAC malignancy. Tumor multiplicity (p = 0.009), tumor-to-NAC distance (≤ 20.0 mm, p = 0.014)), and NAC-SUVR_delay (> 1.23, p = 0.018) had independent predictive value for NAC involvement.

Conclusions

Delayed ¹⁸F-FDG PET/CT is a useful modality for predicting NAC involvement in breast cancer patients whether or not NAC symptoms are present.

Role of breast magnetic resonance imaging in predicting malignant invasion of the nipple-areolar complex: Potential predictors and reliability between inter-observers

In this study, we assessed the diagnostic accuracy of breast magnetic resonance imaging (MRI) for evaluation of malignant invasion of the nipple-areolar complex (NAC).Patients with primary operable breast cancer who underwent preoperative breast MRI and received surgery during January 2011 to December 2013 were collected. The accuracy and potential factors of MRI in predicting nipple invasion were evaluated by comparing preoperative MRI with postoperative histopathologic findings. The consistency of interobservers' variances across different radiologists was also compared.Totally, 704 patients were enrolled in this study, and 56 (8%) patients have pathologic NAC invasion. Several MRI factors were potential predictors of nipple invasion. Only unilateral nipple enhancement on MRI was the most significant independent predictor of NAC involvement in multivariate analysis. The statistical measures, such as sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the accuracy of breast MRI were 71.4%, 81.6%, 25.2%, 97.1%, and 80.8%, respectively, in one investigator and 78.6%, 88.1%, 36.4%, 97.9%, and 87.4%, respectively, in the other investigator.MR images showed acceptable accuracy and impressive NPV, but low PPV in evaluation of malignant NAC invasion preoperatively. MRI finding of unilateral nipple enhancement was the most significant predictor of NAC involvement.

Takeaways from Pre-Contrast T1 and T2 Breast Magnetic Resonance Imaging in Women with Recently Diagnosed Breast Cancer

Background

Dynamic contrast-enhanced magnetic resonance imaging (DCE - MRI) has been widely used in the management of breast cancer, and its diagnostic value in breast imaging has been demonstrated. There have only been a few reports regarding the usefulness of pre-contrast imaging. Knowledge about clinically significant findings of preoperative, pre-contrast T1 and T2 MR images will allow more accurate decisions regarding patient treatment and management.

Objectives

The aim of this study was to evaluate the clinically significant findings of preoperative, pre-contrast T1 and T2 MR images in recently diagnosed breast cancer patients.

Patients and Methods

We analyzed 390 preoperative 3-T MRIs of recently diagnosed breast cancer patients in whom the diagnosis was confirmed by a core needle biopsy.

Results

MRI findings that were correlated with post-core needle-biopsy changes were observed in 27.9% of the pre-contrast T1 and T2 MRIs (n = 109/390). Two of 35 cases that had a subareolar ductal high signal area on the pre-contrast T1 were confirmed by surgery as having nipple-areolar complex involvement.

Conclusion

A subareolar ductal high signal area on a pre-contrast T1 MRI must be carefully assessed in combination with dynamic, contrast-enhanced images for proper surgical management.