Perforator versus Non-Perforator Flap-Based Vulvoperineal Reconstruction-A Systematic Review and Meta-Analysis.

BACKGROUND: Patients with advanced vulvoperineal cancer require a multidisciplinary treatment approach to ensure oncological safety, timely recovery, and the highest possible quality of life (QoL). Reconstructions in this region often lead to complications, affecting approximately 30% of patients. Flap design has evolved towards perforator-based approaches to reduce functional deficits and (donor site) complications, since they allow for the preservation of relevant anatomical structures. Next to their greater surgical challenge in elevation, their superiority over non-perforator-based approaches is still debated. METHODS: To compare outcomes between perforator and non-perforator flaps in female vulvoperineal reconstruction, we conducted a systematic review of English-language studies published after 1980, including randomized controlled trials, cohort studies, and case series. Data on demographics and surgical outcomes were extracted and classified using the Clavien-Dindo classification. We used a random-effects meta-analysis to derive a pooled estimate of complication frequency (%) in patients who received at least one perforator flap and in patients who received non-perforator flaps. RESULTS: Among 2576 screened studies, 49 met our inclusion criteria, encompassing 1840 patients. The overall short-term surgical complication rate was comparable in patients receiving a perforator (n = 276) or a non-perforator flap (n = 1564) reconstruction (p* > 0.05). There was a tendency towards fewer complications when using perforator flaps. The assessment of patients' QoL was scarce. CONCLUSIONS: Vulvoperineal reconstruction using perforator flaps shows promising results compared with non-perforator flaps. There is a need for the assessment of its long-term outcomes and for a systematic evaluation of patient QoL to further demonstrate its benefit for affected patients.

Improving quality of life after breast cancer: a comparison of two microsurgical treatment options for breast cancer-related lymphedema (BCRL).

PURPOSE: Vascularized lymph node transfer (VLNT) entails the autologous relocation of lymph nodes to a lymphedematous region of the body, whereas lymphaticovenous anastomosis (LVA) creates a direct bypass between the lymphatic and venous system. Both techniques are meant to lastingly bolster the local lymphatic drainage capacity. This study compared safety and effectiveness of VLNT and LVA in patients with chronic breast cancer related lymphedema (BCRL). METHODS: A retrospective cohort study was conducted using data from our encrypted database composed of patients with chronic BCRL who were treated with either VLNT or LVA and had a minimum follow-up of two years. Patient-specific variables analyzed included pre- and postoperative arm circumferences, lymphedema stages and postoperative complications. RESULTS: A total of 105 patients met the inclusion criteria, of which 96 patients demonstrated a complete follow-up period of two years. The VLNT group displayed larger preoperative circumferential measurements, evident in both in the isolated examination of the affected arm, as well as when adjusted for the contralateral unaffected arm. Significant reduction in arm volume was achieved by both groups. However, VLNT demonstrated superior relative reduction rates than LVA, neutralizing any significant arm size disparities after 24 months. Surgery duration was slightly longer for VLNT than LVA. Postoperative complications, predominantly minor, were exclusively observed in the VLNT group. CONCLUSIONS: Both VLNT and LVA offer significant improvement for patients suffering from chronic BCRL. VLNT shows an even greater potential for improvement in more severe cases of BCRL, but involves a higher risk for (mostly minor) complications.

Melanoma Clonal Heterogeneity Leads to Secondary Resistance after Adoptive Cell Therapy with Tumor-Infiltrating Lymphocytes.

Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TIL) is effective in patients with melanoma, although long-term responses seem restricted in patients who have complete remissions. Many patients develop secondary resistance to TIL-ACT but the involved mechanisms are unclear. In this study, we describe a case of secondary resistance to TIL-ACT possibly due to intratumoral heterogeneity and selection of a resistant tumor cell clone by the transferred T cells. To the best our knowledge, this is the first case of clonal selection of a pre-existing nondominant tumor cell clone; this report demonstrates the mechanism involved in secondary resistance to TIL-ACT that can potentially change current clinical practice because it advocates for T-cell collection from multiple tumor sites and analysis of tumor heterogeneity before treatment with TIL-ACT.

Impact of adjuvant radiochemotherapy on free flap volume in head and neck reconstruction: A systematic review and meta-analysis.

BACKGROUND: Limited data exist regarding the effect of adjuvant radiochemotherapy on free flap volume in head and neck reconstruction. However, an adequate free flap volume is an important predictor of functional and patient-reported outcomes in head and neck reconstruction. METHODS: A systematic review of Medline, Embase, and the Cochrane Central Register of Controlled Trials was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A total of 6710 abstracts were screened, and 36 full-text papers were reviewed. Nineteen studies met the inclusion criteria and were used to extract data for this analysis. RESULTS: A meta-analysis of 14 two-arm studies comparing the impact of adjuvant radiotherapy versus no adjuvant radiotherapy was performed. The main analysis revealed that 6 months postoperatively, irradiated flaps showed a significant reduction of volume (average, 9.4%) compared to nonirradiated flaps. The average interpolated pooled flap volumes 6 months postoperatively were 76.4% in irradiated flaps and 81.8% in nonirradiated flaps. After a median postoperative follow-up of 12 months, the total flap volume was 62.6% for irradiated flaps and 76% for nonirradiated flaps. Four studies reported that chemotherapy had no significant impact on free flap volume. CONCLUSIONS: Compared to nonirradiated flaps, irradiated flaps were significantly reduced in volume (range, 5% to 15.5%). Clinicians should take this into account when planning the surgical reconstruction of head and neck defects. Conducting large-scale prospective studies with standardized protocols and well-defined follow-up measurements could contribute to defining the ideal, personalized free flap volume for optimal function and patient-reported outcomes.

Detection of N-glycolyl-neuraminic acid-containing glycolipids in human skin.

Humans lack the enzyme that produces the sialic acid N-glycolyl neuraminic acid (Neu5Gc), but several lines of evidence have shown that Neu5Gc can be taken up by mammalian food sources and replace the common human sialic acid N-acetyl neuraminic acid (Neu5Ac) in glycans. Cancer tissue has been shown to have increased the presence of Neu5Gc and Neu5Gc-containing glycolipids such as the ganglioside GM3, which have been proposed as tumor-specific antigens for antibody treatment. Here, we show that a previously described antibody against Neu5Gc-GM3 is binding to Neu5GC-containing gangliosides and is strongly staining different cancer tissues. However, we also found a strong intracellular staining of keratinocytes of healthy skin. We confirmed this staining on freshly isolated keratinocytes by flow cytometry and detected Neu5Gc by mass spectrometry. This finding implicates that non-human Neu5Gc can be incorporated into gangliosides in human skin, and this should be taken into consideration when targeting Neu5Gc-containing gangliosides for cancer immunotherapy.

Harnessing human adipose-derived stromal cell chondrogenesis in vitro for enhanced endochondral ossification.

Endochondral ossification (ECO), the major ossification process during embryogenesis and bone repair, involves the formation of a cartilaginous template remodelled into a functional bone organ. Adipose-derived stromal cells (ASC), non-skeletal multipotent progenitors from the stromal vascular fraction (SVF) of human adipose tissue, were shown to recapitulate ECO and generate bone organs in vivo when primed into a hypertrophic cartilage tissue (HCT) in vitro. However, the reproducibility of ECO was limited and the major triggers remain unknown. We studied the effect of the expansion of cells and maturation of HCT on the induction of the ECO process. SVF cells or expanded ASC were seeded onto collagen sponges, cultured in chondrogenic medium for 3-6 weeks and implanted ectopically in nude mice to evaluate their bone-forming capacities. SVF cells from all tested donors formed mature HCT in 3 weeks whereas ASC needed 4-5 weeks. A longer induction increased the degree of maturation of the HCT, with a gradually denser cartilaginous matrix and increased mineralization. This degree of maturation was highly predictive of their bone-forming capacity in vivo, with ECO achieved only for an intermediate maturation degree. In parallel, expanding ASC also resulted in an enrichment of the stromal fraction characterized by a rapid change of their proteomic profile from a quiescent to a proliferative state. Inducing quiescence rescued their chondrogenic potential. Our findings emphasize the role of monolayer expansion and chondrogenic maturation degree of ASC on ECO and provides a simple, yet reproducible and effective approach for bone formation to be tested in specific clinical models.

Guideline adherence to statin therapy and association with short-term and long-term cardiac complications following noncardiac surgery: A cohort study.

BACKGROUND: Peri-operative complications are common and associated with high morbidity and mortality. Optimising the use of statins might be of important benefit in peri-operative care and reduce morbidity and mortality. OBJECTIVE: To evaluate adherence to current guideline recommendations regarding statin therapy and its association with peri-operative and long-term cardiac complications. DESIGN: Prospective cohort study. SETTING: Multicentre study with enrolment from October 2014 to February 2018. PATIENTS: Eight thousand one hundred and sixteen high-risk inpatients undergoing major noncardiac surgery who were eligible for the institutional peri-operative myocardial injury/infarction (PMI) active surveillance and response program. MAIN OUTCOME MEASURES: Class I indications for statin therapy were derived from the current ESC Clinical Practice Guidelines during the time of enrolment. PMI was prospectively defined as an absolute increase in cTn concentration of the 99th percentile in healthy individuals above the preoperative concentration within the first three postoperative days. Long-term cardiac complications included cardiovascular death and spontaneous myocardial infarction (MI) within 120 days. RESULTS: The mean age was 73.7 years; 45.2% were women. Four thousand two hundred and twenty-seven of 8116 patients (52.1%) had a class I indication for statin therapy. Of these, 2440 of 4227 patients (57.7%) were on statins preoperatively. Adherence to statins was lower in women than in men (46.9 versus 63.9%, P  < 0.001). PMI due to type 1 myocardial infarction/injury (T1MI; n  = 42), or likely type 2 MI (lT2MI; n  = 466) occurred in 508 of 4170 (12.2%) patients. The weighted odds ratio in patients on statin therapy was 1.15 [95% confidence interval (CI) 1.01 to 1.31, P  = 0.036]. During the 120-day follow-up, 192 patients (4.6%) suffered cardiovascular death and spontaneous MI. After multivariable adjustment, preoperative use of statins was associated with reduced risk; weighted hazard ratio 0.59 (95% CI 0.41 to 0.86, P  = 0.006). CONCLUSION: Adherence to guideline-recommended statin therapy was suboptimal, particularly in women. Statin use was associated with an increased risk of PMI due to T1MI and lT2MI but reduced risk of cardiovascular death and spontaneous MI within 120 days. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02573532.

Minimal-Invasive Mitral Valve Repair after Breast Augmentation.

Minimal-invasive mitral valve surgery after breast augmentation is an ongoing interdisciplinary challenge. Notably, the perioperative explantation of the breast implant, as reported in most cases, is of questionable benefit. We herein report on successful minimal-invasive mitral valve repair after subpectoral breast augmentation with perioperative preservation of the breast implant in situ.

Human epidermis organotypic cultures, a reproducible system recapitulating the epidermis in vitro.

The translatability of research is highly dependent on models that recapitulate human tissues and organs. Here, we describe a procedure for the generation of human epidermis organotypic cultures (HEOCs) from primary keratinocytes isolated from foreskin and adult skin as well as from an immortalized keratinocyte cell line (KerTr). We tested several media conditions to develop a defined HEOC growing and expansion media. We characterized the HEOCs and show that in optimal culture conditions they express the proliferation marker Ki67, the basement membrane protein collagen 17 (col17) and the epidermal differentiation markers keratin 15 (K15), keratin 14 (K14), keratin 5 (K5), keratin 10 (K10), keratin 1 (K1), transglutaminase 1 (TGM1), transglutaminase 3 (TGM3) and filaggrin (FLG). Thus, they recapitulate the human epidermis and are stratified from the basal layer to the stratum corneum. These HEOC can be generated reproducibly on a large scale, making it an invaluable model for screening therapeutic compounds and also for the study of pathologies affecting the epidermis.

Long-term outcomes of perioperative myocardial infarction/injury after non-cardiac surgery.

AIMS: Perioperative myocardial infarction/injury (PMI) following non-cardiac surgery is a frequent cardiac complication. Better understanding of the underlying aetiologies and outcomes is urgently needed. METHODS AND RESULTS: Aetiologies of PMIs detected within an active surveillance and response programme were centrally adjudicated by two independent physicians based on all information obtained during clinically indicated PMI work-up including cardiac imaging among consecutive high-risk patients undergoing major non-cardiac surgery in a prospective multicentre study. PMI aetiologies were hierarchically classified into 'extra-cardiac' if caused by a primarily extra-cardiac disease such as severe sepsis or pulmonary embolism; and 'cardiac', further subtyped into type 1 myocardial infarction (T1MI), tachyarrhythmia, acute heart failure (AHF), or likely type 2 myocardial infarction (lT2MI). Major adverse cardiac events (MACEs) including acute myocardial infarction, AHF (both only from day 3 to avoid inclusion bias), life-threatening arrhythmia, and cardiovascular death as well as all-cause death were assessed during 1-year follow-up. Among 7754 patients (age 45-98 years, 45% women), PMI occurred in 1016 (13.1%). At least one MACE occurred in 684/7754 patients (8.8%) and 818/7754 patients died (10.5%) within 1 year. Outcomes differed starkly according to aetiology: in patients with extra-cardiac PMI, T1MI, tachyarrhythmia, AHF, and lT2MI 51%, 41%, 57%, 64%, and 25% had MACE, and 38%, 27%, 40%, 49%, and 17% patients died within 1 year, respectively, compared to 7% and 9% in patients without PMI. These associations persisted in multivariable analysis. CONCLUSION: At 1 year, most PMI aetiologies have unacceptably high rates of MACE and all-cause death, highlighting the urgent need for more intensive treatments. STUDY REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02573532.

The impact of neoadjuvant systemic treatment on postoperative complications in breast cancer surgery.

PURPOSE: The aim of the study was to analyze the impact of neoadjuvant systemic treatment (NST) on postoperative complications and the beginning of adjuvant treatment. METHODS: This study includes data from a prospectively maintained database including patients with breast cancer (BC) stage I-IV with or without NST undergoing breast cancer surgery between January 2010 and September 2021. RESULTS: Out of 517 enrolled patients, 77 received NST, 440 had primary breast surgery. After NST patients underwent surgery after a meantime of 34 days (26.5-40 days). No statistical significance could be found comparing the complication grading according to the Clavien Dindo classification. The complications were most frequently rated as grade 3b. There were no complications with grade 4 or higher. When differentiating into short and long-term, the overall rate of short-term complications was 20.3% with no significant difference between the two groups (20.8% vs. 20.2%). Regarding long-term complications, there was more impairment of shoulder mobility (26.0% vs. 9.5%, p ≤ 0.001) and chronic pain (42.9% vs. 28.6%, p ≤ 0.016) for patients with NST. The beginning of the administration of the adjuvant treatment was comparable in both groups (46.3 days vs. 50.5 days). CONCLUSION: In our cohort, complications between both groups were comparable according to Clavien Dindo. This study shows that NST has no negative impact on postoperative short-term complications and most importantly did not lead to a delay of the beginning of adjuvant treatment. Therefore, NST can be safely admitted, even when followed by extensive breast reconstruction surgery.

Combining reconstructive and ablative surgical treatment of chronic breast cancer-related lymphedema (BCRL): safe and effective.

PURPOSE: We investigated whether a one-stage combination of vascularized lymph node transfer (VLNT) with water jet-assisted liposuction (WAL) can be safely performed and results in improved patient outcomes such as a greater reduction in arm volume when treating chronic breast cancer-related lymphedema (BCRL). METHODS: In this retrospective cohort study, we included all patients from our encrypted lymphedema database treated for chronic BCRL with VLNT or VLNT + WAL who had a minimum follow-up of two years. We analyzed patient-specific variables including arm circumferences as well as patient-reported outcomes before and after surgery as well as surgery time, surgery-related complications and patient satisfaction. RESULTS: Only the mean preoperative differences of the circumferences between the lymphedematous and the unaffected arm in individual patients showed a statistically significant difference between treatment groups (p < 0.05). Indeed, patients treated with VLNT + WAL had consistently larger differences in individual sets of arms and therefore more pronounced chronic BCRL. The mean surgery time was significantly longer in the VLNT + WAL group (p < 0.05). Complications were seldom and similar in both groups. Using a numeric rating scale, the level of patient satisfaction following treatment did not differ significantly between groups (p = 0.323). CONCLUSIONS: Our findings suggest that a one-stage combination of VLNT with WAL does not result in more complications even though it also entails a longer surgery time. This is acceptable as secondary interventions resulting in overall longer surgery times and higher costs can be avoided. A one-stage combination might be especially favourable for patients suffering from more severe chronic BCRL.

Impact of Adjuvant Radiotherapy on Free Flap Volume in Autologous Breast Reconstruction: A Scoping Review.

In autologous breast reconstruction, a sufficient flap volume is fundamental to restore breast shape and ensure an aesthetic outcome. After mastectomy, postoperative irradiation is regularly indicated in the oncological treatment algorithm. When administering radiation therapy after autologous reconstruction, the tissue transferred is inherently irradiated. Although there is evidence that points to a reduction in flap volume after adjuvant radiotherapy, the data have been contradicting and inconclusive. To address this anecdotal evidence, we performed a scoping review of the current literature that addresses the effect of radiotherapy on breast flap volume. Six two-armed studies, comprising a total of 462 patients, reported on the effect of adjuvant radiotherapy on free flap volume changes. Of those, two studies found a significant negative impact of radiotherapy on free flap volume, while the other four studies did not. Reported flap volume changes ranged from no change to a reduction of 26.2%, measured up to two years postoperatively. The selected studies contain varying patient numbers, follow-up timepoints, types of flaps, and measuring methods, contributing to a relatively high heterogeneity. While we present some evidence suggesting a significant impact of adjuvant radiotherapy on breast flap volume, future studies are needed to further investigate this potential correlation.

The impact of delayed wound healing on patient-reported outcomes after breast cancer surgery.

PURPOSE: Postoperative complications after breast cancer surgery may be associated with decreased quality of life. It remains unclear whether oncoplastic breast-conserving surgery or mastectomy with reconstruction lead to more postoperative complications than conventional breast surgery (CBS). As delayed wound healing (DWH) is one of the most frequent minor complications, we sought to investigate the significance of DWH for patient-reported outcomes after oncoplastic, reconstructive, and CBS. METHODS: Our study is a retrospective cohort study of consecutive patients with stage I-II breast cancer who underwent oncoplastic or CBS performed by three breast surgeons at a single tertiary referral hospital from June 2011 until May 2019. Patient-reported outcomes were evaluated postoperatively using the BREAST-Q questionnaire. Comparisons were made between patients with and without DWH. RESULTS: A total of 229 patients who met the inclusion criteria and 28 (12%) of them developed DWH, 27/158 (17%) in the oncoplastic breast-conserving surgery and reconstruction group and 1/71 (1%) in the CBS group. The mean time from surgery to BREAST-Q assessment was comparable in both groups (29 months in the DWH vs. 33 months in the normal wound healing group). No statistically significant difference for any BREAST-Q scale was detected between patients with and without DWH. This includes physical (p = 0.183), psychosocial (p = 0.489), sexual well-being (p = 0.895), and satisfaction with breasts (p = 0.068). CONCLUSION: Our study confirms that oncoplastic breast-conserving surgery and mastectomy with reconstruction lead to significantly more DWH than CBS. However, neither quality of life nor patient-reported outcomes following state-of-the-art reconstructive or oncoplastic breast-conserving surgery at a specialized center seem to be compromised.

Brustrekonstruktion ­ der Einfluss des Verfahrens auf die Lebensqualität.

English Breast cancer and the surgical procedures associated with it have a major impact on the quality of life of affected patients. Research shows that the loss of the breast and the associated change in body image have a major impact on the female self-image for many women. This has a strong negative impact on the quality of life of those affected. With modern clinical outcome research including treatment results from the patient's perspective in the form of patient-reported outcome measures (PROMs), the satisfaction and quality of life of those affected can be measured, analysed and compared. This review examines the extent to which breast reconstruction improves the quality of life for many women and how the different reconstruction methods vary in their impact on quality of life and satisfaction. In addition, the review discusses the importance of standardised recording and analysis of PROMs in combination with objective clinical data and their integration into the treatment process, and it demonstrates implementation options. Such systematic recording of PROMs enables the creation of databases and registers, the evaluation of which provides information that can be used for scientific and clinical purposes. Based on these research results, prognostic models can be created and treatment results can be examined in comparative studies facilitating clinical decision-making and quality controls.

Comparison of patient-reported outcomes among different types of oncoplastic breast surgery procedures.

BACKGROUND: This study aims to compare patient-reported outcomes (PROs) after different types of oncoplastic surgery (OPS) procedures and correlate the results with previously published normative data from women with no prior history of breast cancer (BC) and breast surgery. METHODS: Cross-sectional study of patients with stage I-II BC undergoing a specific selection of OPS procedures from 04/2012 to 12/2018 by three breast surgeons at a single tertiary referral hospital in Switzerland. PROs were evaluated using the postoperative BREAST-Q questionnaire. RESULTS: One hundred twenty-seven patients met the inclusion criteria and were surveyed. All OPS techniques achieved comparably elevated scores in satisfaction with breasts, psychosocial, and sexual well-being. Compared to normative data of healthy women, all OPS groups postoperatively achieved significantly better satisfaction with breasts, psychosocial, and sexual well-being. CONCLUSION: This study shows high PROs across all types of OPS, which were superior to normative data from healthy women. Our findings confirm that OPS is associated with high quality of life and patient satisfaction.

The double S technique to achieve aesthetic flat closure after conventional mastectomy.

BACKGROUND: Lateral excess tissue after mastectomy is a frequent problem, which should be included into preoperative planning. Women with lateral tissue abundance are frequently impaired cosmetically and functionally. We suggest a novel oncoplastic mastectomy technique to eliminate the above mentioned. METHODS: Surgical technique Two small horizontal lines are drawn, one line above and one line below the Nipple Areola Complex. These lines should represent the possible skin excision and allow tight skin closure. Consecutively, two ending points of the incision are planned, one close to the xyphoid area and the other one in the anterior axillary line. These points are then interconnected in an s-shaped manner to form a double s-shaped skin excision. RESULTS: The double S-shaped technique is an easy reproducible technique which not only allows good access to the lateral side of the mastectomy, but also and mainly the reduction of lateral fat and skin. CONCLUSION: The double S mastectomy allows for simultaneous removal of access in the axillary region, eliminating skin, and fat as needed and preventing the lateral dog ear.

Impact of Oncoplastic Breast Surgery on Rate of Complications, Time to Adjuvant Treatment, and Risk of Recurrence.

BACKGROUND: The aim of this study was to compare the risk of complications and recurrence between oncoplastic and conventional breast surgery. METHODS: This is a retrospective analysis of a consecutive series of 436 patients with stage I-III breast cancer who underwent surgery at the University Hospital of Basel between 2011 and 2018. RESULTS: The nipple/skin-sparing mastectomy (NSM/SSM) group showed significantly more delayed wound healing (32.7 vs. 5.8%, p < 0.001) and skin necrosis (13.9 vs. 1.9%, p = 0.020) compared to conventional mastectomy (CM), which corresponded to significantly higher odds of short-term complications (OR 2.34, 95% CI 1.02-5.35, p = 0.044). The incidence rate of long-term morbidity in oncoplastic breast-conserving surgery (OBCS) was significantly higher compared to conventional breast-conserving surgery (CBCS; 25.5 vs. 11.3 per 100 patient years [PY], p < 0.001), in particular concerning chronic pain (13.3 vs. 6.6, p = 0.011) and lymphedema (4.1 vs. 0.4, p = 0.003). Seroma as a long-term morbidity occurred more often in the CM group compared to the NSM/SSM group (5.8 vs. 0.5 per 100 PY, p = 0.004). Patients received adjuvant treatment earlier after CM compared to NSM/SSM (HR 1.83, 95% CI 1.05-3.19, p = 0.034). There were no significant differences in the incidence of positive margins nor in the odds of recurrence after OBCS versus CBCS and after NSM/SSM versus CM. CONCLUSIONS: Even though the present study confirmed expected differences in complications and morbidity, it suggested that oncoplastic surgery is oncologically safe. Patients undergoing NSM/SSM should be followed closely to allow early detection and treatment of frequently associated complications and ensure timely start of adjuvant therapy.

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.