HER2 copy number determination in breast cancer using the highly sensitive droplet digital PCR method.

Human epidermal growth factor receptor 2 (HER)-positive breast cancer (BC) is characterized by an aggressive clinical course. In the case of HER2 overexpression/amplification, patients benefit from HER2-targeting therapies. Standardized diagnostic HER2 assessment includes immunohistochemistry (IHC) and/or in situ hybridization (ISH). The aim of this study was to compare this "gold standard" with the Droplet Digital™ polymerase chain reaction (ddPCR), a method that allows sensitive and precise detection of copy number variations (CNV) in FFPE (formalin-fixed, paraffin-embedded) DNA samples. Partitioning of the PCR reaction into 20,000 droplets enables a precise quantitative "CN" discrimination also in heterogeneous samples. FFPE breast cancer samples (n = 170) with routinely assessed HER2 status by IHC/ISH were retrospectively analyzed using the ddPCR CNV ERBB2 assay. Comparison of HER2 status assessment by the two methods revealed concordant results in 92.9% (158/170) of the cases. Discrepant cases were verified and interpreted. For ddPCR, a cut off value of 3 HER2 copies was set to distinguish between HER2-negative and HER2-positive BC. Results obtained with the ddPCR CNV ERBB2 assay were consistent and reproducible, and serial dilutions demonstrated a high stability and sensitivity of the method. The ddPCR CNV ERBB2 assay may be a specific and convenient tool to quantify HER2 copy numbers in BC samples. In our study, this method showed high reproducibility in accuracy of HER2 assessment compared to IHC/ISH analysis.

Trends in use of neoadjuvant systemic therapy in patients with clinically node-positive breast cancer in Europe: prospective TAXIS study (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101).

PURPOSE: The aim of this study was to evaluate clinical practice heterogeneity in use of neoadjuvant systemic therapy (NST) for patients with clinically node-positive breast cancer in Europe. METHODS: The study was preplanned in the international multicenter phase-III OPBC-03/TAXIS trial (ClinicalTrials.gov Identifier: NCT03513614) to include the first 500 randomized patients with confirmed nodal disease at the time of surgery. The TAXIS study's pragmatic design allowed both the neoadjuvant and adjuvant setting according to the preferences of the local investigators who were encouraged to register eligible patients consecutively. RESULTS: A total of 500 patients were included at 44 breast centers in six European countries from August 2018 to June 2022, 165 (33%) of whom underwent NST. Median age was 57 years (interquartile range [IQR], 48-69). Most patients were postmenopausal (68.4%) with grade 2 and 3 hormonal receptor-positive and human epidermal growth factor receptor 2-negative breast cancer with a median tumor size of 28 mm (IQR 20-40). The use of NST varied significantly across the countries (p < 0.001). Austria (55.2%) and Switzerland (35.8%) had the highest percentage of patients undergoing NST and Hungary (18.2%) the lowest. The administration of NST increased significantly over the years (OR 1.42; p < 0.001) and more than doubled from 20 to 46.7% between 2018 and 2022. CONCLUSION: Substantial heterogeneity in the use of NST with HR+/HER2-breast cancer exists in Europe. While stringent guidelines are available for its use in triple-negative and HER2+ breast cancer, there is a need for the development of and adherence to well-defined recommendations for HR+/HER2-breast cancer.

Axillary lymph node status and invasive lobular breast cancer : Analysis of the Clinical Tumor Register of the AGO Austria.

BACKGROUND: Invasive lobular carcinoma (ILC) represents the second most common type of invasive breast cancer (BC). Although ILC generally have good prognostic properties (positive estrogen receptor, ER, low tumor grade), they are generally diagnosed at a more advanced stage. The data on the axillary lymph node status in ILC compared to invasive ductal carcinoma (IDC) are considered controversial. Therefore, the aim of this study was to compare the pathological node stage (pN) between ILC and IDC in an Austria-wide register. METHODS: Data of the Clinical Tumor Register (Klinisches TumorRegister, KTR) of the Austrian Association for Gynecological Oncology (AGO) were retrospectively analyzed. Patients with primary early BC, invasive lobular or ductal, diagnosed between January 2014 and December 2018, and primary surgery were included. A total of 2127 tumors were evaluated and compared in 2 groups, ILC n = 303, IDC n = 1824. RESULTS: A total of 2095 patients were analyzed in the study. In the multivariate analysis, pN2 and pN3 were observed significantly more frequently in ILC compared with IDC (odds ratio, OR 1.93; 95% confidence interval, CI 1.19-3.14; p = 0.008 and OR 3.22; 95% CI: 1.47-7.03; p = 0.003; respectively). Other factors associated with ILC were tumor grades 2 and 3, positive ER, and pathological tumor stage (pT) 2 and pT3. In contrast, concomitant ductal carcinoma in situ, overexpression of the human epidermal growth factor receptor 2 (HER2), and a moderate and high proliferation rate (Ki67) were found less frequently in ILC. CONCLUSION: The data show an increased risk of extensive axillary lymph node metastasis (pN2/3) in ILC.

Patient-reported outcomes for the Intergroup Sentinel Mamma study (INSEMA): A randomised trial with persistent impact of axillary surgery on arm and breast symptoms in patients with early breast cancer.

Background: In clinically node-negative breast cancer patients, the INSEMA trial (NCT02466737) assessed the non-inferiority of avoiding sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND). Here we present patient-reported outcomes (PROs) as a secondary endpoint. Methods: PROs were assessed for patients with no axillary surgery, SLNB alone, and ALND. Quality of life (QoL) questionnaire EORTC QLQ-C30 and its breast cancer module (BR23) were used at baseline (pre-surgery) and 1, 3, 6, 12, and 18 months after surgery. The QoL scores were compared using repeated measures mixed models based on the safety set. Findings: Between 2015 and 2019, 5502 patients were recruited for the first randomization, and 5154 were included in the intent-to-treat set (4124 SLNB versus 1030 no SLNB). In the case of one to three macrometastases after SLNB, 485 patients underwent second randomization (242 SLNB alone versus 243 ALND). Questionnaire completion response remained high throughout the trial: over 70% at all time points for the first randomization. There were significant differences for the BRBS (breast symptoms) and BRAS (arm symptoms) scores favoring the no SLNB group in all post-baseline assessments. Patients in the SLNB group showed significantly and clinically relevant higher scores for BRAS (differences in mean values ≥5.0 points at all times), including pain, arm swelling, and impaired mobility in all postoperative visits, with the highest difference at one month after surgery. Scoring of the QLQ-C30 questionnaire revealed no relevant differences between the treatment groups, although some comparisons were statistically significant. Interpretation: This is one of the first randomized trials investigating the omission of SLNB in clinically node-negative patients and the first to report comprehensive QoL data. Patients with no SLNB benefitted regarding arm symptoms/functioning, while no relevant differences in other scales were seen. Funding: Supported by German Cancer Aid (Deutsche Krebshilfe, Bonn, Germany), Grant No. 110580 and Grant No. 70110580 to University Medicine Rostock.

Oncoplastic breast consortium recommendations for mastectomy and whole breast reconstruction in the setting of post-mastectomy radiation therapy.

AIM: Demand for nipple- and skin- sparing mastectomy (NSM/SSM) with immediate breast reconstruction (BR) has increased at the same time as indications for post-mastectomy radiation therapy (PMRT) have broadened. The aim of the Oncoplastic Breast Consortium initiative was to address relevant questions arising with this clinically challenging scenario. METHODS: A large global panel of oncologic, oncoplastic and reconstructive breast surgeons, patient advocates and radiation oncologists developed recommendations for clinical practice in an iterative process based on the principles of Delphi methodology. RESULTS: The panel agreed that surgical technique for NSM/SSM should not be formally modified when PMRT is planned with preference for autologous over implant-based BR due to lower risk of long-term complications and support for immediate and delayed-immediate reconstructive approaches. Nevertheless, it was strongly believed that PMRT is not an absolute contraindication for implant-based or other types of BR, but no specific recommendations regarding implant positioning, use of mesh or timing were made due to absence of high-quality evidence. The panel endorsed use of patient-reported outcomes in clinical practice. It was acknowledged that the shape and size of reconstructed breasts can hinder radiotherapy planning and attention to details of PMRT techniques is important in determining aesthetic outcomes after immediate BR. CONCLUSIONS: The panel endorsed the need for prospective, ideally randomised phase III studies and for surgical and radiation oncology teams to work together for determination of optimal sequencing and techniques for PMRT for each patient in the context of BR.

Transferring MINDACT to Daily Routine: Implementation of the 70-Gene Signature in Luminal Early Breast Cancer - Results from a Prospective Registry of the Austrian Group Medical Tumor Therapy (AGMT).

Background: For hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative early breast cancer (EBC), adjuvant chemotherapy (ACT) is recommended in the case of high-risk features only. The MINDACT trial showed that patients with high clinical risk (CR) but low genomic risk (GR) defined by the 70-gene signature (MammaPrint®; 70-GS) did not benefit from ACT. In this registry, we investigated the frequency and feasibility of 70-GS and concurrent 80-gene subtyping (BluePrint®) use in HR-positive, HER2-negative EBC. Furthermore, we recorded the frequency of ACT recommendation and the adherence to it when the "MINDACT strategy" was used. Methods: This prospective registry included patients from 2 Austrian cancer centers. Similar to MINDACT, a modified version of Adjuvant!Online was used to determine CR, and 70-GC was used to determine GR in high-CR patients. ACT was recommended to patients with high CR and high GR. Results: Of 224 enrolled patients, 76 (33.9%) had high CR and 67 (88.2%) received genomic testing. Of those, 43 (64.2%) were classified as low and 24 (35.8%) as high GR, respectively. All 24 patients with high CR and GR (10.7% of all patients) received the recommendation for ACT, but ACT was started in only 15 patients (62.5%). The median time from surgery to the start of ACT was 45 days (range 32-68), and the median time from test decision to the test result was 15 days (range 9-56). Conclusion: We showed that the results of the MINDACT trial are reproducible in an Austrian population. Incorporating 70-GS into the daily clinical routine is feasible and mostly accepted by physicians for the guidance of treatment recommendations.

Hypofractionated Whole Breast Irradiation and Boost-IOERT in Early Stage Breast Cancer (HIOB): First Clinical Results of a Prospective Multicenter Trial (NCT01343459).

Background and purpose: To investigate intraoperative electron radiation therapy (IOERT) as a tumor bed boost during breast conserving surgery (BCS) followed by hypofractionated whole breast irradiation (HWBI) on age-correlated in-breast recurrence (IBR) rates in patients with low- to high-risk invasive breast cancer. Material and methods: BCS and IOERT (11.1 Gy) preceded a HWBI (40.5 Gy) in 15 fractions. Five-year IBR-rates were compared by a sequential ratio test (SQRT) with best evidences in three age groups (35−40 y and 41−50 y: 3.6%, >50 y: 2%) in a prospective single arm design. Null hypothesis (H0) was defined to undershoot these benchmarks for proof of superiority. Results: Of 1445 enrolled patients, 326 met exclusion criteria, leaving 1119 as eligible for analysis. After a median follow-up of 50 months (range 0.7−104), we detected two local recurrences, both in the age group >50 y. With no observed IBR, superiority was demonstrated for the patient groups 41−50 and >50 y, respectively. For the youngest group (35−40 y), no appropriate statistical evaluation was yet possible due to insufficient recruitment. Conclusions: In terms of five-year IBR-rates, Boost-IOERT followed by HWBI has been demonstrated to be superior in patients older than 50 and in the age group 41−50 when compared to best published evidence until 2010.

Tailored axillary surgery in patients with clinically node-positive breast cancer: Pre-planned feasibility substudy of TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101).

AIM: We developed tailored axillary surgery (TAS) to reduce the axillary tumor volume in patients with clinically node-positive breast cancer to the point where radiotherapy can control it. The aim of this study was to quantify the extent of tumor load reduction achieved by TAS. METHODS: International multicenter prospective study embedded in a randomized trial. TAS is a novel pragmatic concept for axillary surgery de-escalation that combines palpation-guided removal of suspicious nodes with the sentinel procedure and, optionally, imaging-guided localization. Pre-specified study endpoints quantified surgical extent and reduction of tumor load. RESULTS: A total of 296 patients were included at 28 sites in four European countries, 125 (42.2%) of whom underwent neoadjuvant chemotherapy (NACT) and 71 (24.0%) achieved nodal pathologic complete response. Axillary metastases were detectable only by imaging in 145 (49.0%) patients. They were palpable in 151 (51.0%) patients, of whom 63 underwent NACT and 21 had residual palpable disease after NACT. TAS removed the biopsied and clipped node in 279 (94.3%) patients. In 225 patients with nodal disease at the time of surgery, TAS removed a median of five (IQR 3-7) nodes, two (IQR 1-4) of which were positive. Of these 225 patients, 100 underwent ALND after TAS, which removed a median of 14 (IQR 10-17) additional nodes and revealed additional positive nodes in 70/100 (70%) of patients. False-negative rate of TAS in patients who underwent subsequent ALND was 2.6%. CONCLUSIONS: TAS selectively reduced the tumor load in the axilla and remained much less radical than ALND.

Prepectoral versus subpectoral implant-based breast reconstruction after skin-sparing mastectomy or nipple-sparing mastectomy (OPBC-02/ PREPEC): a pragmatic, multicentre, randomised, superiority trial.

INTRODUCTION: The emphasis on aesthetic outcomes and quality of life (QoL) has motivated surgeons to develop skin-sparing or nipple-sparing mastectomy (SSM/ NSM) for breast cancer treatment or prevention. During the same operation, a so-called immediate breast reconstruction is performed. The breast can be reconstructed by positioning of a breast implant above (prepectoral) or below (subpectoral) the pectoralis major muscle or by using the patients' own tissue (autologous reconstruction). The optimal positioning of the implant prepectoral or subpectoral is currently not clear. Subpectoral implant-based breast reconstruction (IBBR) is still standard care in many countries, but prepectoral IBBR is increasingly performed. This heterogeneity in breast reconstruction practice is calling for randomised clinical trials (RCTs) to guide treatment decisions. METHODS AND ANALYSIS: International, pragmatic, multicentre, randomised, superiority trial. The primary objective of this trial is to test whether prepectoral IBBR provides better QoL with respect to long-term (24 months) physical well-being (chest) compared with subpectoral IBBR for patients undergoing SSM or NSM for prevention or treatment of breast cancer. Secondary objectives will compare prepectoral versus subpectoral IBBR in terms of safety, QoL and patient satisfaction, aesthetic outcomes and burden on patients. Total number of patients to be included: 372 (186 per arm). ETHICS AND DISSEMINATION: This study will be conducted in compliance with the Declaration of Helsinki. Ethical approval has been obtained for the lead investigator's site by the Ethics Committee 'Ethikkommission Nordwest- und Zentralschweiz' (2020-00256, 26 March 2020). The results of this study will be published in a peer-reviewed medical journal, independent of the results, following the Consolidated Standards of Reporting Trials standards for RCTs and good publication practice. Metadata describing the type, size and content of the datasets will be shared along with the study protocol and case report forms on public repositories adhering to the FAIR (Findability, Accessibility, Interoperability, and Reuse) principles. TRIAL REGISTRATION NUMBER: NCT04293146.

Hsa-miR-375/RASD1 Signaling May Predict Local Control in Early Breast Cancer.

BACKGROUND: In order to characterize the various subtypes of breast cancer more precisely and improve patients selection for breast conserving therapy (BCT), molecular profiling has gained importance over the past two decades. MicroRNAs, which are small non-coding RNAs, can potentially regulate numerous downstream target molecules and thereby interfere in carcinogenesis and treatment response via multiple pathways. The aim of the current two-phase study was to investigate whether hsa-miR-375-signaling through RASD1 could predict local control (LC) in early breast cancer. RESULTS: The patient and treatment characteristics of 81 individuals were similarly distributed between relapse (n = 27) and control groups (n = 54). In the pilot phase, the primary tumors of 28 patients were analyzed with microarray technology. Of the more than 70,000 genes on the chip, 104 potential hsa-miR-375 target molecules were found to have a lower expression level in relapse patients compared to controls (p-value < 0.2). For RASD1, a hsa-miR-375 binding site was predicted by an in silico search in five mRNA-miRNA databases and mechanistically proven in previous pre-clinical studies. Its expression levels were markedly lower in relapse patients than in controls (p-value of 0.058). In a second phase, this finding could be validated in an independent set of 53 patients using ddPCR. Patients with enhanced levels of hsa-miR-375 compared to RASD1 had a higher probability of local relapse than those with the inverse expression pattern of the two markers (log-rank test, p-value = 0.069). CONCLUSION: This two-phase study demonstrates that hsa-miR-375/RASD1 signaling is able to predict local control in early breast cancer patients, which-to our knowledge-is the first clinical report on a miR combined with one of its downstream target proteins predicting LC in breast cancer.

A novel humanized mouse model to study the function of human cutaneous memory T cells in vivo in human skin.

Human skin contains a population of memory T cells that supports tissue homeostasis and provides protective immunity. The study of human memory T cells is often restricted to in vitro studies and to human PBMC serving as primary cell source. Because the tissue environment impacts the phenotype and function of memory T cells, it is crucial to study these cells within their tissue. Here we utilized immunodeficient NOD-scid IL2rγnull (NSG) mice that carried in vivo-generated engineered human skin (ES). ES was generated from human keratinocytes and fibroblasts and was initially devoid of skin-resident immune cells. Upon adoptive transfer of human PBMC, this reductionist system allowed us to study human T cell recruitment from a circulating pool of T cells into non-inflamed human skin in vivo. Circulating human memory T cells preferentially infiltrated ES and showed diverse functional profiles of T cells found in fresh human skin. The chemokine and cytokine microenvironment of ES closely resembled that of non-inflamed human skin. Upon entering the ES T cells assumed a resident memory T cell-like phenotype in the absence of infection, and a proportion of these cutaneous T cells can be locally activated upon injection of monocyte derived dendritic cells (moDCs) that presented Candida albicans. Interestingly, we found that CD69+ memory T cells produced higher levels of effector cytokines in response to Candida albicans, compared to CD69- T cells. Overall, this model has broad utility in many areas of human skin immunology research, including the study of immune-mediated skin diseases.

Central Review of Radiation Therapy Planning Among Patients with Breast-Conserving Surgery: Results from a Quality Assurance Process Integrated into the INSEMA Trial.

PURPOSE: After publication of the radiation field design in the American College of Surgeons Oncology Group Z0011 trial, a radiation therapy quality assurance review was integrated into the Intergroup-Sentinel-Mamma (INSEMA) trial. We aimed to investigate the role of patient characteristics, extent of axillary surgery, and radiation techniques for dose distribution in ipsilateral axillary levels. METHODS AND MATERIALS: INSEMA (NCT02466737) has randomized 5542 patients who underwent breast-conserving surgery. Of these, 276 patients from 108 radiation therapy facilities were included in the central review, using the planning records of the first 3 patients treated at each site. RESULTS: Of the 276 patients, 41 had major deviations (ie, no axillary contouring or submission of insufficient records) leading to exclusion. A total of 235 (85.1%) radiation therapy planning records were delineated according to the INSEMA protocol, including 9 (3.8%) cases with minor deviations. At least 25% of INSEMA patients were unintentionally treated with ≥95% of the prescribed breast radiation dose in axillary level I. Approximately 50% of patients were irradiated with a median radiation dose of more than 85% of prescription dose in level I. Irradiated volumes and applied doses were significantly lower in levels II and III compared with level I. However, 25% of patients still received a median radiation dose of ≥75% of prescription dose to level II. Subgroup analysis revealed a significant association between incidental radiation dose in the axilla and obesity. Younger age, boost application, and fractionation schedule showed no impact on axillary dose distribution. CONCLUSIONS: Assuming ≥80% of prescribed breast dose as the optimal dose for curative radiation of low-volume disease in axillary lymph nodes, at least 50% of reviewed INSEMA patients received an adequate dose in level I, even with contemporary 3-dimensional techniques. Dose coverage was much less in axillary levels II and III, and far below therapeutically relevant doses.

Complication rates among women undergoing preventive mastectomy: An Austrian registry.

Germline variations in the BRCA-1 and BRCA-2 genes are associated with an increased risk of breast cancer. These variants are found in 5% of all breast cancer cases. Prophylactic mastectomy is the most effective risk-reducing method and shows high rates of patient satisfaction and acceptance. We established a registry of Austrian BRCA-1 and BRCA-2 mutation carriers who had undergone mastectomy for oncologic or prophylactic reasons. Data were collected on the type of operation, complications, and type of reconstructive surgery for patients between 2014 and 2017. The complication rate in patients with nipple-sparing mastectomy was significantly lower (23.1%) than in those with other types of mastectomies (60.7%; P = .005). In patients with implant-based breast reconstruction, subpectoral placement was associated with a significantly higher rate of complications than prepectoral placement (P = .025). Median implant volume was 350 cc (range: 155-650 cc), and a 100-cc increase was associated with doubling of the odds of a complication (regression coefficient = 0.007); based on this finding, some surgeons may decide on using smaller implants. In summary, we identified significant associations between the risk of complications and surgical characteristics, and found host factors like diabetes, BMI, and smoking among Austrian patients with BRCA-1 and BRCA-2 variants.

Toxicity and cosmetic outcome after hypofractionated whole breast irradiation and boost-IOERT in early stage breast cancer (HIOB): First results of a prospective multicenter trial (NCT01343459).

BACKGROUND AND PURPOSE: To assess the role of intraoperative radiation with electrons (IOERT) as tumor bed boost followed by hypofractionated whole breast irradiation (HWBI) after breast conserving surgery (BCS) of patients with low to intermediate risk breast cancer focusing on acute/late toxicity and cosmetic outcome. MATERIAL AND METHODS: In 2011, a prospective multicenter trial (NCT01343459) was started. Treatment consisted of BCS, IOERT (11.1 Gy) and HWBI (40.5 Gy in 15 fractions). In a single-arm design, 5-year IBR-rates are benchmarked by a sequential ratio test (SQRT) against best published evidences in 3 age groups (35-40 y, 41-50 y, >50 y). Acute/late toxicity and cosmesis were evaluated by validated scorings systems. RESULTS: Of 627 eligible patients, 44 were excluded, leaving 583 to analyze. After a median follow-up (FUP) of 45 months (range 0-74), for acute effects CTCAE-score 0/1 was noted in 91% (end of HWBI) and 92% (4 weeks later), respectively. Late toxicity Grading 0/1 (mean values, ranges) by LENT-SOMA criteria were observed in 92.7% (89-97.3) at 4/5 months, rising to 96.5% (91-100) at 6 years post HWBI. Baseline cosmesis after wound healing prior to HWBI was scored as excellent/good in 86% of cases by subjective (patient) and in 74% by objective (doctor) assessment with no impairment thereafter. CONCLUSIONS: Acute and late treatment tolerance of a combined Boost-IOERT/HWBI regimen is excellent in short/mid-term assessment. Postoperative cosmetic appearance is not impaired after 3 years FUP.

Prepectoral direct-to-implant breast reconstruction with complete ADM or synthetic mesh coverage - 36-Months follow-up in 200 reconstructed breasts.

BACKGROUND: Prepectoral implant placement is an innovative option for breast reconstruction, due to multiple advantages over subpectoral implant placement. The adoption of various ADMs and meshes supports the utilization of the prepectoral technique. METHODS: 200 breasts were reconstructed with prepectoral implant placement after nipple-sparing mastectomy in a one-stage direct-to-implant procedure. The implants were completely covered and fixed with porcine ADMs (Strattice™ or Artia™), or with synthetic meshes (TIGR®). The pectoralis major muscle was not detached at all and kept intact entirely. RESULTS: Minor complications included minimal nipple necrosis without further intervention and complete healing in 14 breasts (7.0%). Major complications comprised implant loss due to skin necrosis and wound infection in 7 breasts (3.5%), and hematoma with revision surgery in 8 breasts (4.0%). At a mean follow-up of 36 months cosmetic results were excellent and good in 180 breasts (90.0%), sufficient in 13 breasts (6.5%) and insufficient in 7 breasts (3.5%). Breast animation deformity and implant displacement could not be observed, while implant rotation was documented in 5 breasts (2.5%). Capsular contractures grade III or IV could not be observed neither in patients with previous radiotherapy nor in patients with radiotherapy to the reconstructed breast. CONCLUSIONS: The single-stage direct-to-implant prepectoral implant placement after NSM with complete coverage of the implant with ADM or synthetic mesh represents a novel and feasible technique for breast reconstruction. This technique provides an alternative to the subpectoral implant placement with excellent cosmetic results avoiding the disadvantages of the subpectoral implant placement.

Prepectoral implant-based breast reconstruction: a joint consensus guide from UK, European and USA breast and plastic reconstructive surgeons.

Advances in implantable biologic and synthetic products over the last decade have enabled surgeons to replace traditional submuscular implant-based breast reconstruction techniques with a prepectoral or muscle-sparing technique. Prepectoral breast reconstruction is becoming increasingly popular among surgeons and patients due to the preservation of normal chest wall anatomy, with the restoration of body image with minimal morbidity. In this article, we have described a guide to prepectoral or muscle-sparing breast reconstruction with a particular emphasis on patient selection, technique and postoperative outcomes. Hence, a joint consensus guide from European and USA breast and plastic reconstructive surgeons has been agreed, and a crowd-writing method has been adopted to produce this guide.