Magnetic resonance imaging (MRI) evaluation of residual breast tissue following mastectomy and reconstruction with silicone implants

Risk factors for residual fibroglandular breast tissue following a mastectomy - an overview and retrospective cohort study

BACKGROUND

Residual fibroglandular breast tissue (RFGT) following a mastectomy is associated with the remaining of occult breast cancer at the time of mastectomy as well as an increased local recurrence risk thereafter. Despite its oncologic implications, data on measures to prevent RFGT are lacking. Therefore, in a first step knowledge of risk factors for RFGT is of uttermost importance in order to allow identification of patients at risk and subsequently adaption of the surgical treatment and potentially prevention of RFGT a priori.

METHODS

We performed a systematic literature review in PubMed using the MESH terms [residual fibroglandular breast tissue], [residual breast tissue], [mastectomy] and [risk factor] followed by a retrospective data analysis including all patients with a mastectomy treated at the Department of Obstetrics and Gynecology of the Medical University of Vienna, Austria, between 01.01.2015 and 26.02.2020 in order to identify risk factors of RFGT following a mastectomy. The primary aim of the study was to assess a potential difference in RFGT volume between the different types of mastectomy. The secondary objectives of the study were to identify other potential risk factors for RFGT as well as to compare the skin and subcutaneous fat tissue thickness pre- to postoperatively.

RESULTS

Significantly higher RFGT volumes were observed following a nipple-sparing mastectomy (NSM) compared to a skin-sparing mastectomy (SSM) and radical mastectomy (RME) (p < .001). Furthermore, RFGT volume was significantly associated with the variables: reconstruction (p = .012), acellular dermal matrix (ADM) or mesh (p = .031), patient age (p = .022), preoperative fibroglandular tissue (FGT) volume (p = .012) and preoperative whole breast volume (including the skin envelope and nipple-areola-complex) (p = .030). The reduction in the postoperative compared to preoperative skin envelope thickness measured medially and laterally reached statistical significance in the NSM-cohort (medial p < .001, lateral p = .001) and showed a numerical difference in the RME and SSM-cohort.

CONCLUSION

Mastectomy type, reconstruction, ADM or mesh, patient age, preoperative FGT volume and whole breast volume were identified as risk factors for RFGT in univariable analysis. The observed reduction in the post- compared to preoperative skin envelope thickness should be avoided considering the known associated increase in risk for ischemic complications.

A BRILLIANT-BRCA study: residual breast tissue after mastectomy and reconstruction

INTRODUCTION

Different types of mastectomies leave different amounts of residual breast tissue. The significance of the residual breast volume (RBV) is not clear. Therefore, we developed an MRI tool that allows to easily assess the RBV. In this study we evaluated factors associated with RBV after skin or nipple sparing mastectomy (SSM/NSM) in breast cancer BRCA pathogenic variant (PV) carriers who underwent both therapeutic and risk reducing SSM/NSM and its relation to breast cancer outcomes using an innovative MRI-based tool.

METHODS

Data of breast cancer BRCA PV who were treated between 2006 and 2020 were retrieved from of the oncogenetics unit databases. Only patients who underwent SSM/NSM and had a postoperative breast MRI available for analysis were included. Data collected included demographics, clinicopathological features, and outcomes. The MRI tool was developed by a breast cancer imaging laboratory. A logistic regression test and 95% confidence interval (CI) were used to assess the associated risk of increased RBV. A forward stepwise linear regression was used to correlate tumour-patient specific factors and RBV, and a Kaplan-Meier curve to show the probability of locoregional relapse.

RESULTS

A total of 84 patients undergoing 89 mastectomies were included. At a median follow-up of 98 months, 5 local, 2 regional, and 4 distant recurrences were observed. RBV was not significantly related with breast cancer outcomes (p value = NS). A higher body mass index (BMI) was associated with a higher RBV (p < 0.0001). A larger number of involved axillary nodes was associated with a smaller RBV (p = 0.025). The RBV on the risk-reducing mastectomy side was significantly higher compared to the breast cancer side (p value = 0.007). Local recurrences occurred in the vicinity of the primary tumour.

Residual fibroglandular breast tissue after mastectomy is associated with an increased risk of a local recurrence or a new primary breast cancer"

BACKGROUND

Residual fibroglandular breast tissue (RFGT) following a mastectomy has been claimed to be associated with the occurrence of an in-breast local recurrence (IBLR) or new primary tumor (NP). Yet, scientific evidence proving this assumption is lacking. The primary aim of the study was to verify whether RFGT following a mastectomy is a risk factor for an IBLR or NP.

METHODS

This retrospective analysis included all patients that underwent a mastectomy and were followed up at the Department of Obstetrics and Gynecology of the Medical University of Vienna between 01.01.2015 and 26.02.2020. RFGT volume (assessed on magnetic resonance imaging) was correlated with the prevalence of an IBLR and a NP.

RESULTS

A total of 105 patients (126 breasts) following a therapeutic mastectomy were included. After a mean follow-up of 46.0 months an IBLR had occurred in 17 breasts and a NP in 1 breast. A significant difference in RFGT volume was observed between the disease-free cohort and the subgroup with an IBLR or NP (p = .017). A RFGT volume of ≥ 1153 mm³ increased the risk by the factor 3.57 [95%CI 1.27; 10.03].

CONCLUSIONS

RFGT volume is associated with an increased risk for an IBLR or NP.

Factors Influencing Residual Glandular Breast Tissue after Risk-Reducing Mastectomy in Genetically Predisposed Individuals Detected by MRI Mammography

PURPOSE

This study seeks to evaluate MR imaging morphological factors and other covariates that influence the presence of residual glandular tissue after risk-reducing mastectomy in patients with a familial predisposition.

METHODS

We analyzed women of a high-risk collective with pathogenic mutation (BRCA1 (n = 49), BRCA2 (n = 24), or further mutation (n = 9)). A total of 117 breasts were analyzed, 63 left and 54 right, from a cohort of 81 patients, who were on average 40 years old. The mean follow-up was 63 months (range 12-180 months, SD = 39.67). Retrospective analysis of MR imaging data from 2006-2022 of patients of a high-risk collective (all carriers of a pathogenic mutation) with contralateral (RRCM) or bilateral risk-reducing mastectomy (RRBM) was performed. In the image data the remaining skin flap thickness by distance measurements at eight equally distributed, clockwise points and the retromamillary area, as well as by volumetry of each breast, was elected. Residual glandular tissue was also volumetrized. In addition, patient-related covariates were recorded and their influence on postoperative residual glandular tissue and skin flap thickness was analyzed by uni- and multivariate regressions.

RESULTS

A significant association with postoperative residual glandular tissue was shown in multivariate analysis for the independent variables breast density, skin flap mean, and surgical method (all p-values < 0.01). A negatively significant association could be seen for the variables preoperative breast volume (p-values < 0.01) and surgeon experience (most p-values < 0.05-<0.1).

CONCLUSION

Postoperative residual glandular tissue is an important tool for quantifying the risk of developing breast cancer after risk-reducing mastectomy. Different effects on residual glandular tissue were shown for the independent variables breast density, skin flap, surgical method, preoperative breast volume, and surgeon experience, so these should be considered in future surgical procedures preoperatively as well as postoperatively. Breast MRI has proven to be a suitable method to analyze the skin flap as well as the RGT.

The PreQ-20 TRIAL: A prospective cohort study of the oncologic safety, quality of life and cosmetic outcomes of patients undergoing prepectoral breast reconstruction

Background

Mastectomy currently constitutes a necessary surgical procedure in the oncologic setting and in the context of high risk. Prepectoral breast reconstruction (PBR) has been proposed as a surgical alternative to retropectoral techniques by providing less postoperative morbidity and a better cosmetic result. However, there is a lack of prospective studies that have evaluated its safety and patient-reported satisfaction.

Methods

We conducted a prospective cohort study to assess the safety, quality of life and cosmetic sequelae of PBR in women with breast cancer and high risk. The study’s main objective is to assess the safety of PBR in terms of postsurgical complications and the feasibility of reconstruction (loss of implants). The secondary objectives are to evaluate oncologic safety (local relapses, residual glandular tissue) and to identify factors related to quality of life and cosmetic sequelae. The evaluation of residual tissue will be conducted by MRI 12 to 18 months after the surgery, and the quality-of-life assessment will be performed using the Breast-Q questionnaire. An initial patient evaluation will be conducted 12–18 months after the surgery, and a second evaluation will be performed at 5 years. The estimated sample size is 81 patients.

Discussion

The PreQ-20 study will analyze the impact of PBR on 3 separate measures: safety, quality of life and cosmetic sequelae. Unlike other studies that analyzed these three measures jointly for women with breast cancer and high risk, this study will individualize the results for these 2 patient groups. This differentiation is necessary from the methodological point of view, given that the 2 patient groups have separate clinical and emotional implications. The assessment of these groups will focus on the following aspects: postoperative complications, local relapses, evaluation of residual glandular tissue and incidence rate of primary tumors in the same, the cosmetic sequelae and the satisfaction and the quality-of-life assessment by the patients.

Trial registration

ClinicalTrials.gov: NCT04642508.

Pregnancy induced hyperplasia of residual breast tissue following risk reducing contralateral mastectomy - simply interesting or a clinically important observation

After a diagnosis of breast cancer women with increased genetic risk often have a risk reducing contralateral mastectomy, and may opt for a nipple or skin sparing mastectomy with immediate reconstruction. A variable amount of residual breast tissue remains which may substantially increase in volume during pregnancy. Whether this increases later risk of breast cancer is unknown. We describe the clinical details of 3 patients with a history of unilateral breast cancer, including 2 with a BRCA mutation, who developed hyperplasia of residual breast tissue in the 3rd trimester of a later pregnancy. They all had a delayed contralateral risk reducing skin sparing mastectomy and immediate reconstruction. Pregnancy occurred some years later. We summarise their management, review the literature and raise questions for discussion. All developed prominent hyperplasia of breast tissue in the 3rd trimester that was clinically obvious asymmetrical breast swelling in the reconstructed contralateral breast. MRI demonstrated substantial breast tissue. The risk of breast cancer, particularly in those at high genetic risk developing in the residual breast tissue is unknown but in view of the volume, breast tissue was excised postpartum. This phenomenon of pregnancy induced hyperplasia of breast tissue after risk reducing mastectomy is not well described .There is residual breast tissue following a risk reducing subcutaneous mastectomy. The risk factors include age and skin flap thickness. MRI can demonstrate the residual breast tissue. Pregnancy induced hyperplasia of residual breast tissue may occur after risk reducing mastectomy with a hypothetical increased risk of subsequent breast cancer.

Clinical and MRI Evaluation of Silicone Gel Implants with RFID-M Traceability System: A Prospective Controlled Cohort Study Related to Safety and Image Quality in MRI Follow-Up

BACKGROUND

SmoothSilk implants (SSI) are the first generation of implants to incorporate a radio-frequency identification device (RFID-M), a non-invasive traceability system. Although the RFID-M is considered compatible with magnetic resonance imaging (MRI), the size of the artifact and its influence on breast tissue vary. This prospective study assessed safety and MRI issues in a cohort of breast reconstruction patients.

METHODS

Forty-four SSI were used for breast reconstruction in patients undergoing treatment for breast cancer. All patients were evaluated for magnetic field interactions, MRI-related heating and artifacts in a 1.5-T MRI unit using standard T1/T2-weighted sequences utilized in clinical assessment of breast tissue/implants.

RESULTS

Mean patient age was 41.5 years (27-53ys) and body mass index was 28+-6.44 kg/m². In 18/22 patients (81.8%), mastectomies were unilateral. No patients reported local heat/discomfort. All implants showed RFID-M-related artifacts with an estimated mean volume in T1 of 42.9cm³ (26.2-63.6cm³; SD±8.6 and 95% CI, 40.37-45.45) and in T2 of 60.5cm³ (35.4-97.2cm³; SD±14.7 and 95% CI, 56.29-65.01). Artifact volume was smaller in T1 than in T2, to a statistically significant degree (p <0.001). There were no statistically significant differences in artifact volume according to surgical indication, breast side or implant volume. There were 4/44 (9%) cases of minor rotation (<45°). In all cases, adequate analysis of the breast tissue was performed.

CONCLUSIONS

The results demonstrate that SSI with RFID-M technology presented an artifact volume of 42.9cm³ and 60.5cm³ in T1 and T2 images, respectively. Our findings provide detailed information on the quality and location of MRI artifacts in a reconstructed cohort which can help guide clinical decision-making for patients. To our knowledge, this is the first time RFID-M breast implants have been prospectively evaluated for clinical and MRI issues in a cohort of reconstructive patients.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Post-mastectomy surveillance of BRCA1/BRCA2 mutation carriers: Outcomes from a specialized clinic for high-risk breast cancer patients

Female BRCA1/BRCA2 mutation carriers may elect bilateral risk-reducing mastectomy. There is a paucity of data on yield of imaging surveillance after risk-reducing mastectomy. This retrospective study focused on female BRCA1/BRCA2 mutation carriers who underwent bilateral mastectomy either as primary preventative, or as secondary preventative, after breast cancer diagnosis. All participants underwent breast imaging at 6- to 12-month intervals after mastectomy. Data on subsequent breast cancer diagnosis and timing were collected and compared between the groups. Overall, 184 female mutation carriers (134 BRCA1, 45 BRCA2, 5 both BRCA genes) underwent bilateral mastectomy after initial breast cancer diagnosis, between April 1, 2009 and August 31, 2018. During a mean follow-up of 6.2 ± 4.2 years, 13 (7.06%) were diagnosed with breast cancer; 12 ipsilateral (range: 0.4-28.8 years) and 1 contralateral breast cancer, 15.9 years after surgery. On the contrary, among asymptomatic BRCA1 (n = 40) and BRCA2 (n = 13) mutation carriers who underwent primary risk-reducing mastectomy (mean age at surgery 39.5 ± 8.4 years); none has developed breast cancer after a mean follow-up of 5.4 ± 3.4 years. BRCA1/BRCA2 mutation carriers with prior disease who underwent risk-reducing mastectomy after breast cancer diagnosis are still prone for developing ipsi or contralateral breast cancer, and therefore may benefit from continues clinical and imaging surveillance, unlike BRCA1/BRCA2 mutation carriers who undergo primary preventative bilateral mastectomy.

A multidisciplinary view of mastectomy and breast reconstruction: Understanding the challenges

The current review paper was written in collaboration with breast cancer surgeons from the European Breast Cancer Research Association of Surgical Trialists (EUBREAST), a breast pathologist from the Danish Breast Cancer Group (DBCG), and representatives from the European SocieTy for Radiotherapy & Oncology (ESTRO) breast cancer course. Herein we summarize the different mastectomies and reconstruction procedures and define high-risk anatomical areas for breast cancer recurrences, to further specify the challenges in the surgical procedure, histopathological evaluation, and target volumes in case of postmastectomy irradiation, as recommended by the ESTRO guidelines according to the surgical procedure. The paper has original figures and illustrations for all disciplines for in-depth understanding of the differences between the procedures.

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Mastectomy techniques and reconstruction evolved to improve cosmetic outcomes.

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Different techniques maybe associated with different amount of residual breast tissue.

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More data is needed to estimate who are the patients at risk for residual disease or recurrence.

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Multidisciplinary work needed to individualise treatment for optimal oncological outcomes while maintaining the significant improvements in achieving better cosmesis for these patients.

Locoregional Treatments and Ipsilateral Breast Cancer Recurrence Rates in BRCA1/2 Mutation Carriers

PURPOSE

There is a paucity of data on the rates of ipsilateral breast tumor recurrence (IBTR) in BRCA1/2-associated breast cancer (BC). Scarcer yet are outcomes data in BRCA1/2 mutation carriers in the setting of newer mastectomy techniques, such as skin-sparing mastectomies (SSM) and nipple-sparing mastectomies (NSM).

METHODS

Data were extracted from the medical records of BRCA1/2 carriers who were diagnosed with BC and treated at a single institution between 2006 and 2020. The data extracted included patient demographics, tumor characteristics, disease stage, surgical treatment, use of radiation therapy (RT), and disease outcome.

RESULTS

Overall, 255 BC patients with BRCA1/2 germline mutations were identified. Of these, 128 (50.2%) underwent a mastectomy (SSM or NSM in 82% of them), 76 (59.4%) without postmastectomy RT (non-PMRT) and 52 (40.6%) with PMRT, whereas 127 (49.8%) elected for breast-conserving treatment (BCT). The non-PMRT group had earlier disease stages (82.3% were Tis and T1N0) compared with the PMRT and BCT groups (3.6% and 48.1%, respectively; P < .05). The IBTR cumulative rate was 9 of 76 (11.8%) in the non-PMRT cohort compared with 0 of 52 in the PMRT group (P = .01) and 6 of 127 (4.7%) in the BCT group (P = .06). The cumulative incidences of IBTR at 5 and 10 years were 9.8% and 27.4%, respectively, in the non-PMRT group versus 2% and 11.3%, respectively, in the BCT group (P = .0183). No significant difference in overall survival was observed at the time of follow-up.

CONCLUSIONS

BRCA1/2 mutation carriers treated with mastectomy without PMRT had higher rates of IBTR than those who underwent mastectomy and PMRT or BCT, despite earlier stages of disease. The safety of SSM/NSM should be evaluated in a prospective trial.

Spatial location of local recurrences after mastectomy: a systematic review

PURPOSE

We performed a systematic review to document the spatial location of local recurrences (LR) after mastectomy.

METHODS

A PubMed search was conducted in August 2019 for the following terms: breast [Title/Abstract] AND cancer [Title/Abstract] AND recurrence [Title/Abstract] AND mastectomy [Title/Abstract]. The search was filtered for English language. Exclusion criteria included studies that did not specify the LR location or studies reporting LR associated with inflammatory breast cancer, or other breast cancers such as phyllodes tumours, lymphoma or associated with sarcoma/angiosarcoma.

RESULTS

A total of 3922 titles were identified, of which 21 publications were eligible for inclusion in the final analysis. A total of 6901 mastectomy patients were included (range 25-1694). The mean LR proportion was 3.5%. Among the total of 351 LR lesions, 81.8% were in the subcutaneous tissue and the skin, while 16% were pectoral muscle recurrences.

CONCLUSION

Local recurrences are mostly located within the subcutaneous tissue and the skin, assumed to result from unrecognized/subclinical tumour foci left behind after mastectomy, surgical implantation of tumour cells in the wound/scar and/or tumour emboli within the subcutaneous lymphatics. Pectoral muscle recurrences are less frequent and may be attributed to residual disease along the posterior surgical margin and/or lymphatic involvement.

The Attachments of the Breast to the Chest Wall: A Dissection Study

BACKGROUND

The anatomical descriptions of the attachments of the female breast to the chest wall vary in their structure, location, and terminology within the published literature.

METHODS

A dissection study of the attachments of the breast to the chest wall was conducted on 18 female embalmed breasts in the coronal (n = 15) and sagittal planes (n = 3).

RESULTS

Perimeter, posterior wall, and horizontal septum attachments were observed. The perimeter along its entire length was attached to the chest wall. Regional and anatomical variation was observed in this structure and location. Sharp dissection was required to remove it from the chest wall, in contrast to the blunt dissection required to remove the posterior wall and horizontal septum attachments.

CONCLUSIONS

The breast attaches to the chest wall along its entire perimeter, posterior wall, and horizontal septum, with the perimeter functioning as the primary anchor of the breast to the chest wall. The structure of the perimeter attachment is both periosteal and fascial and requires sharp dissection to remove it from the chest wall. The fascial structures of the posterior wall and horizontal septum require blunt dissection only. The structure of the perimeter has regional variation, and its location on the chest wall has anatomical variation. Detailed anatomical descriptions and illustrations are supported by photographic evidence of cadaver dissections in two planes. Clinical and anatomical terminology are linked, with clinical implications for medical anatomy education, breast modeling, and breast surgery.

Residual Glandular Breast Tissue After Mastectomy: A Systematic Review

BACKGROUND

The goal of mastectomy is remove all of the glandular breast tissue (BGT) without compromising skin flaps viability. The purpose of this systematic review was to localize and/or estimate the amount of residual BGT (rBGT) after mastectomy and to identify factors that could be related to rBGT and/or residual disease.

METHODS

We conducted a PubMed search. The report was subdivided according to the method used to evaluate the presence of rBGT. A total of 16 publications were included in our final report. Two main methods for identifying rBGT included imaging (i.e., MRI scan) and histological evaluation at the time of mastectomy.

RESULTS

The rate of rBGT was reported in up to 100% of the patients and was found to be associated mainly with the type of surgical resection, indication, and surgeon's expertise. Residual breast tissue can be found in all areas of the remaining chest wall, mostly in the skin-flaps, and more frequently underneath the nipple-areola complex.

Winter is over: The use of Artificial Intelligence to individualise radiation therapy for breast cancer

Artificial intelligence demonstrated its value for automated contouring of organs at risk and target volumes as well as for auto-planning of radiation dose distributions in terms of saving time, increasing consistency, and improving dose-volumes parameters. Future developments include incorporating dose/outcome data to optimise dose distributions with optimal coverage of the high-risk areas, while at the same time limiting doses to low-risk areas. An infinite gradient of volumes and doses to deliver spatially-adjusted radiation can be generated, allowing to avoid unnecessary radiation to organs at risk. Therefore, data about patient-, tumour-, and treatment-related factors have to be combined with dose distributions and outcome-containing databases.

Residual glandular tissue (RGT) in BRCA1/2 germline mutation carriers with unilateral and bilateral prophylactic mastectomies

BACKGROUND

Prophylactic mastectomy (PME) is increasingly performed in women carrying deleterious BRCA1 and BRCA2 germline mutations. The oncologic risk resulting from residual fibroglandular tissue (RGT) is unknown.

METHODS

All women who had received a mastectomy and at least one postoperative breast MRI, between 2006 and 2016 were extracted from the register of the Center for Hereditary Breast and Ovarian Cancer Cologne (CHBOC). The index MRI was evaluated in terms of basic clinical data and the morphological criteria of RGT. The RGT volume was measured in diameter and was semi-automatically evaluated using software.

RESULTS

We identified 169 women carrying BRCA1/2 mutations who underwent prophylactic and curative mastectomy: a total of 338 breasts. RGT was found in 128 of the 338 breasts (37.9%). 68 of the 128 breasts (53.1%) were related to bilateral PME, 37 (28.9%) to unilateral PME and 23 (18.0%) to curative mastectomy. RGT was predominantly unifocal and located in the retroareolar breast region. RGT was observed more often after bilateral PME (p < 0.0001). In this subgroup, the nipple-sparing mastectomy dominated (108 of 136, 79.4%), in contrast to 23 standard mastectomies (23 of 94, 24.5%) in the subgroup of curative mastectomy (23%). There was a trend towards higher amounts of RGT in surgical units with fewer mastectomies performed. During follow-up, two breast cancers were detected after bilateral and unilateral PME, respectively.

CONCLUSIONS

Our results suggest that the indication for surgery and in particular the selected surgical procedure affect the surgical outcome with respect to RGT. Oncological safety should not be neglected, especially in the high-risk group of BRCA1/2 mutation carriers.