Impact of doxorubicin-loaded ferritin nanocages (FerOX) vs. free doxorubicin on T lymphocytes: a translational clinical study on breast cancer patients undergoing neoadjuvant chemotherapy.

Despite the advent of numerous targeted therapies in clinical practice, anthracyclines, including doxorubicin (DOX), continue to play a pivotal role in breast cancer (BC) treatment. DOX directly disrupts DNA replication, demonstrating remarkable efficacy against BC cells. However, its non-specificity toward cancer cells leads to significant side effects, limiting its clinical utility. Interestingly, DOX can also enhance the antitumor immune response by promoting immunogenic cell death in BC cells, thereby facilitating the presentation of tumor antigens to the adaptive immune system. However, the generation of an adaptive immune response involves highly proliferative processes, which may be adversely affected by DOX-induced cytotoxicity. Therefore, understanding the impact of DOX on dividing T cells becomes crucial, to deepen our understanding and potentially devise strategies to shield anti-tumor immunity from DOX-induced toxicity. Our investigation focused on studying DOX uptake and its effects on human lymphocytes. We collected lymphocytes from healthy donors and BC patients undergoing neoadjuvant chemotherapy (NAC). Notably, patient-derived peripheral blood mononuclear cells (PBMC) promptly internalized DOX when incubated in vitro or isolated immediately after NAC. These DOX-treated PBMCs exhibited significant proliferative impairment compared to untreated cells or those isolated before treatment initiation. Intriguingly, among diverse lymphocyte sub-populations, CD8 + T cells exhibited the highest uptake of DOX. To address this concern, we explored a novel DOX formulation encapsulated in ferritin nanocages (FerOX). FerOX specifically targets tumors and effectively eradicates BC both in vitro and in vivo. Remarkably, only T cells treated with FerOX exhibited reduced DOX internalization, potentially minimizing cytotoxic effects on adaptive immunity.Our findings underscore the importance of optimizing DOX delivery to enhance its antitumor efficacy while minimizing adverse effects, highlighting the pivotal role played by FerOX in mitigating DOX-induced toxicity towards T-cells, thereby positioning it as a promising DOX formulation. This study contributes valuable insights to modern cancer therapy and immunomodulation.

In Vitro Immunoreactivity Evaluation of H-Ferritin-Based Nanodrugs.

Biological nanoparticles, such as proteins and extracellular vesicles, are rapidly growing as nanobased drug-delivery agents due to their biocompatibility, high loading efficiency, and bioavailability. However, most of the candidates emerging preclinically hardly confirm their potential when entering clinical trials. Among other reasons, this is due to the low control of synthesis processes and the limited characterization of their potential immunoreactivity profiles. Here, we propose a combined method that allow us to fully characterize H-ferritin nanoparticles' immunoreactivity during their production, purification, endotoxin removal, and drug loading. H-Ferritin is an extremely interesting nanocage that is being under evaluation for cancer therapy due to its innate cancer tropism, favorable size, and high stability. However, being a recombinant protein, its immunoreactivity should be carefully evaluated preclinically to enable further clinical translation. Surprisingly, this aspect is often underestimated by the scientific community. By measuring proinflammatory cytokine release as a function of endotoxin content, we found that even removing all pyrogenic contaminants from the nanocage, a mild immunoreactivity was still left. When we further purified H-ferritin by loading doxorubicin through a highly standardized loading method, proinflammatory cytokine release was eliminated. This confirmed the safety of H-ferritin nanocages to be used for drug delivery in cancer therapy. Our approach demonstrated that when evaluating the safety of nanodrugs, a combined analysis of acute toxicity and immunoreactivity is necessary to guarantee the safety of newly developed products and to unveil their real translational potential.

Ferritin nanoconjugates guide trastuzumab brain delivery to promote an antitumor response in murine HER2 + breast cancer brain metastasis.

Brain metastasis (BM) represents a clinical challenge for patients with advanced HER2 + breast cancer (BC). The monoclonal anti-HER2 antibody trastuzumab (TZ) improves survival of BC patients, but it has low central nervous system penetrance, being ineffective in treating BM. Previous studies showed that ferritin nanoparticles (HFn) may cross the blood brain barrier (BBB) through binding to the transferrin receptor 1 (TfR1). However, whether this has efficacy in promoting the trans-BBB delivery of TZ and combating BC BM was not studied yet. Here, we investigated the potential of HFn to drive TZ brain delivery and promote a targeted antitumor response in a murine model of BC BM established by stereotaxic injection of engineered BC cells overexpressing human HER2. HFn were covalently conjugated with TZ to obtain a nanoconjugate endowed with HER2 and TfR1 targeting specificity (H-TZ). H-TZ efficiently achieved TZ brain delivery upon intraperitoneal injection and triggered stable targeting of cancer cells. Treatment with H-TZ plus docetaxel significantly reduced tumor growth and shaped a protective brain microenvironment by engaging macrophage activation toward cancer cells. H-TZ-based treatment also avoided TZ-associated cardiotoxicity by preventing drug accumulation in the heart and did not induce any other major side effects when combined with docetaxel. These results provided in vivo demonstration of the pharmacological potential of H-TZ, able to tackle BC BM in combination with docetaxel. Indeed, upon systemic administration, the nanoconjugate guides TZ brain accumulation, reduces BM growth and limits side effects in off-target organs, thus showing promise for the management of HER2 + BC metastatic to the brain.

Extensive Intraductal Component in Breast Cancer: What Role in Disease-Free Survival?

INTRODUCTION: Extensive intraductal component (EIC) associated to early breast cancer could increase the risk locoregional recurrence, but its impact on distant metastases is still unclear. The aim of the present study was to assess the role of EIC on 5-year survival outcomes in patients affected by early breast cancer treated with breast-conserving surgery. METHODS: A total of 414 consecutive patients with a minimum follow-up of 60 mo were collected from January 2007 to December 2015. Disease-free survival (DFS), distant metastasis-free survival (DMFS), and locoregional recurrence-free survival at 5 y were assessed considering the presence or absence of EIC and other clinical and pathological features. RESULTS: Absence of EIC was independently associated with worse 5-year DFS (hazard ratio [HR] 1.68, P = 0.008) and 5-year DMFS (HR 1.93, P = 0.007), whereas 5-year locoregional recurrence-free survival was not affected (HR 1.50, P = 0.16). Five-year DFS was increased by EIC in T1 patients (P = 0.03) but not in T2 stage. Moreover, EIC was associated to better DFS in G2 (P = 0.03) and G3 patients (P = 0.01) but not in G1 cases. CONCLUSIONS: Our results suggest that EIC is independently correlated with increased 5-year DFS and in particular with 5-year DMFS.

Determination of the quality of lipoproteins by Raman spectroscopy in obese and healthy subjects.

Lipoproteins (LPs) are multimolecular complexes of lipids and proteins responsible for transporting fatty acids, cholesterol, and micronutrients (carotenoids) through the body. The quantification of triglycerides and cholesterol carried by lipoproteins is a leading clinical parameter to assess the increased risk of cardiovascular events. However, in recent times, the study of the overall "quality" of lipoproteins, defined by their biochemical composition and oxidation state, has emerged as necessary to improve the definition of the cardiovascular risk. In this work, we present Raman spectroscopy (RS) as an effective method to immediately detect the functional groups relative to the principal biochemical components and the level of unsaturated lipids present in LPs. Furthermore, we show how RS can reveal the differences in the biochemical composition and oxidation state of LPs extracted from a cohort of obese patients (Ob) and a control group of healthy subjects (HC). In particular, RS revealed how low-density lipoproteins (LDLs) from obese patients are enriched in triglycerides and more oxidized than those from the control group, while high-density lipoproteins (HDLs) from Ob patients were depleted in cholesterol and phospholipids. RS analysis also allowed the study of the relationship between the levels of carotenoids present in the different classes of LPs highlighting how this parameter depends on the disease severity. Overall, these results demonstrated that RS is a viable approach for quickly and effectively gaining information on LPs' biochemical composition and oxidation state, providing an immediate measure of their quality. Besides, RS further proved the role of LPs in obesity and metabolic dysfunctions.

Fast quantification of extracellular vesicles levels in early breast cancer patients by Single Molecule Detection Array (SiMoA).

PURPOSE: Preliminary reports suggest that extracellular vesicles (EVs) might be a promising biomarker for breast cancer (BC). However, the quantification of plasmatic levels of EVs is a complex task. To overcome these limitations, we developed a new, fast, and easy to use assay for the quantification of EVs directly in plasma based on the use of Single-Molecule Array (SiMoA). METHODS: By using SiMoA to identify CD9+/CD63+ EVs, we analyzed plasma samples of 181 subjects (95 BC and 86 healthy controls, HC). A calibration curve, made of a serial dilution of lyophilized standards from human plasma, was used in each run to ensure the obtainment of quantitative results from the assay. In a subgroup of patients, EVs concentrations were estimated in plasma before and after 30 days from cancer surgery. Additional information on the size of EVs were also acquired using a Nanosight system to obtain a clearer understanding of the mechanism underlying the releases of EVs associated with the presence of cancer. RESULTS: The measured levels of EVs resulted significantly higher in BC patients (median values 1179.1 ng/µl vs 613.0 ng/µl, p < 0.0001). ROC curve was used to define the optimal cut-off level of the test at 1034.5 ng/µl with an AUC of 0.75 [95% CI 0.68-0.82]. EVs plasmatic concentrations significantly decreased after cancer surgery compared to baseline values (p = 0.014). No correlation was found between EVs concentration and clinical features of BC. CONCLUSION: SiMoA assay allows plasmatic EVs levels detection directly without any prior processing. EVs levels are significantly higher in BC patients and significantly decreases after cancer surgery.

Bisdemethoxycurcumin (BDC)-Loaded H-Ferritin-Nanocages Mediate the Regulation of Inflammation in Alzheimer's Disease Patients.

BACKGROUND: Bisdemethoxycurcumin (BDC) might be an inflammation inhibitor in Alzheimer's Disease (AD). However, BDC is almost insoluble in water, poorly absorbed by the organism, and degrades rapidly. We thus developed a new nanoformulation of BDC based on H-Ferritin nanocages (BDC-HFn). METHODS: We tested the BDC-HFn solubility, stability, and ability to cross a blood-brain barrier (BBB) model. We tested the effect of BDC-HFn on AD and control (CTR) PBMCs to evaluate the transcriptomic profile by RNA-seq. RESULTS: We developed a nanoformulation with a diameter of 12 nm to improve the solubility and stability. The comparison of the transcriptomics analyses between AD patients before and after BDC-HFn treatment showed a major number of DEG (2517). The pathway analysis showed that chemokines and macrophages activation differed between AD patients and controls after BDC-HFn treatment. BDC-HFn binds endothelial cells from the cerebral cortex and crosses through a BBB in vitro model. CONCLUSIONS: Our data showed how BDC-Hfn could improve the stability of BDC. Significant differences in genes associated with inflammation between the same patients before and after BDC-Hfn treatment have been found. Inflammatory genes that are upregulated between AD and CTR after BDC-HFn treatment are converted and downregulated, suggesting a possible therapeutic approach.

Stable and scalable SERS tags conjugated with neutravidin for the detection of fibroblast activation protein (FAP) in primary fibroblasts.

SERS tags are a class of nanoparticles with great potential in advanced imaging experiments. The preparation of SERS tags however is complex, as they suffer from the high variability of the SERS signals observed even at the slightest sign of aggregation. Here, we developed a method for the preparation of SERS tags based on the use of gold nanostars conjugated with neutravidin. The SERS tags here obtained are extremely stable in all biological buffers commonly employed and can be prepared at a relatively large scale in very mild conditions. The obtained SERS tags have been used to monitor the expression of fibroblast activation protein alpha (FAP) on the membrane of primary fibroblasts obtained from patients affected by Crohn's disease. The SERS tags allowed the unambiguous identification of FAP on the surface of cells thus suggesting the feasibility of semi-quantitative analysis of the target protein. Moreover, the use of the neutravidin-biotin system allows to apply the SERS tags for any other marker detection, for example, different cancer cell types, simply by changing the biotinylated antibody chosen in the analysis.

Tumor Accumulation and Off-Target Biodistribution of an Indocyanine-Green Fluorescent Nanotracer: An Ex Vivo Study on an Orthotopic Murine Model of Breast Cancer.

Indocyanine green (ICG) is a near infrared fluorescent tracer used in image-guided surgery to assist surgeons during resection. Despite appearing as a very promising tool for surgical oncology, its employment in this area is limited to lymph node mapping or to laparoscopic surgery, as it lacks tumor targeting specificity. Recently, a nanoformulation of this dye has been proposed with the aim toward tumor targeting specificity in order to expand its employment in surgical oncology. This nanosystem is constituted by 24 monomers of H-Ferritin (HFn), which self-assemble into a spherical cage structure enclosing the indocyanine green fluorescent tracer. These HFn nanocages were demonstrated to display tumor homing due to the specific interaction between the HFn nanocage and transferrin receptor 1, which is overexpressed in most tumor tissues. Here, we provide an ex vivo detailed comparison between the biodistribution of this nanotracer and free ICG, combining the results obtained with the Karl Storz endoscope that is currently used in clinical practice and the quantification of the ICG signal derived from the fluorescence imaging system IVIS Lumina II. These insights demonstrate the suitability of this novel HFn-based nanosystem in fluorescence-guided oncological surgery.

Lipofilling in Breast Oncological Surgery: A Safe Opportunity or Risk for Cancer Recurrence?

Lipofilling (LF) is a largely employed technique in reconstructive and esthetic breast surgery. Over the years, it has demonstrated to be extremely useful for treatment of soft tissue defects after demolitive or conservative breast cancer surgery and different procedures have been developed to improve the survival of transplanted fat graft. The regenerative potential of LF is attributed to the multipotent stem cells found in large quantity in adipose tissue. However, a growing body of pre-clinical evidence shows that adipocytes and adipose-derived stromal cells may have pro-tumorigenic potential. Despite no clear indication from clinical studies has demonstrated an increased risk of cancer recurrence upon LF, these observations challenge the oncologic safety of the procedure. This review aims to provide an updated overview of both the clinical and the pre-clinical indications to the suitability and safety of LF in breast oncological surgery. Cellular and molecular players in the crosstalk between adipose tissue and cancer are described, and heterogeneous contradictory results are discussed, highlighting that important issues still remain to be solved to get a clear understanding of LF safety in breast cancer patients.

Raman spectroscopy reveals biochemical differences in plasma derived extracellular vesicles from sporadic Amyotrophic Lateral Sclerosis patients.

Sporadic amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease for which there is no validated blood based biomarker. Extracellular vesicles (EVs) have the potential to solve this unmet clinical need. However, due to their heterogeneity and complex chemical composition, EVs are difficult to study. Raman spectroscopy (RS) is an optical method that seems particularly well suited to address this task. In fact, RS provides an overview of the biochemical composition of EVs quickly and virtually without any sample preparation. In this work, we studied by RS small extracellular vesicles (sEVs), large extracellular vesicles (lEVs) and blood plasma of sporadic ALS patients and of a matched cohort of healthy controls. The obtained results highlighted lEVs as a particularly promising biomarker for ALS. In fact, their Raman spectra show that sporadic ALS patients have a different lipid content and less intense bands relative to the aromatic amino acid phenylalanine.

Fibroblasts in the Tumor Microenvironment.

The implications of a tumor microenvironment in cancer initiation and progression have drawn interest in recent years. Within the tumor stroma, fibroblasts represent a predominant cell type and are responsible for the majority of extracellular components within the tumor microenvironment, such as matrix and soluble factors. A switch from quiescent fibroblasts to cancer-associated fibroblasts triggers a large variety of pro-tumorigenic signals that support tumor progression and shape the surrounding pathological stroma, with the remodeling of tissue architecture and repression of the local immune response. The heterogeneous nature of cancer-associated fibroblasts and their multiple functions are subject of active research as they could represent promising targets for cutting-edge therapeutic approaches to cancer and the tumor microenvironment.

Radio-guided and clip-guided preoperative localization for malignant microcalcifications offer similar performances in breast-conserving surgery.

Obtaining a tailored breast resection is challenging in microcalcifications detected on screening mammography, and an accurate localization is required. The aim of this study was to compare the efficacy of radio-guided localization (ROLL) versus ultrasound localization of a titanium clip with collagen (TCC) in terms of clear margins, re-intervention rates, excess of resected breast tissue, and operative times in pure malignant microcalcifications detected on screening mammography. Two hundred and twenty-one consecutive patients with malignant microcalcifications detected on screening mammography from a tertiary breast unit were reviewed: 177 patients were localized by TCC and 44 patients by stereotactic ROLL. A propensity score-matched analysis was performed, followed by a logistic regression model, to avoid selection bias. Adequacy of resection was expressed as the calculated resection ratio considering lesion size. No differences were found in clear margins with ROLL versus TCC (77.3% vs 81.8%, adjusted OR 2, P = 0.27). Re-operation rates were similar, being 11.3% with ROLL and 7.4% with TCC (P = 0.627). Mean resection volume was 46.2 cm3 with ROLL versus 54.2 cm3 with TCC (P = 0.222). Adjusted mean calculated resection ratio was 1.8 with ROLL and 2.1 with TCC (P = 0.38). Surgery time was longer with TCC compared to ROLL (69.6 vs 52.7 minutes, P < 0.0001). ROLL and TCC are equally effective to excise malignant microcalcifications with clear margins, providing similar re-intervention rates and resection volumes.

Nano-Strategies to Target Breast Cancer-Associated Fibroblasts: Rearranging the Tumor Microenvironment to Achieve Antitumor Efficacy.

Cancer-associated fibroblasts (CAF) are the most abundant cells of the tumor stroma and they critically influence cancer growth through control of the surrounding tumor microenvironment (TME). CAF-orchestrated reactive stroma, composed of pro-tumorigenic cytokines and growth factors, matrix components, neovessels, and deregulated immune cells, is associated with poor prognosis in multiple carcinomas, including breast cancer. Therefore, beyond cancer cells killing, researchers are currently focusing on TME as strategy to fight breast cancer. In recent years, nanomedicine has provided a number of smart delivery systems based on active targeting of breast CAF and immune-mediated overcome of chemoresistance. Many efforts have been made both to eradicate breast CAF and to reshape their identity and function. Nano-strategies for CAF targeting profoundly contribute to enhance chemosensitivity of breast tumors, enabling access of cytotoxic T-cells and reducing immunosuppressive signals. TME rearrangement also includes reorganization of the extracellular matrix to enhance permeability to chemotherapeutics, and nano-systems for smart coupling of chemo- and immune-therapy, by increasing immunogenicity and stimulating antitumor immunity. The present paper reviews the current state-of-the-art on nano-strategies to target breast CAF and TME. Finally, we consider and discuss future translational perspectives of proposed nano-strategies for clinical application in breast cancer.

Half-Chain Cetuximab Nanoconjugates Allow Multitarget Therapy of Triple Negative Breast Cancer.

The use of therapeutic monoclonal antibodies (mAbs) has revolutionized cancer treatment. The conjugation of mAbs to nanoparticles has been broadly exploited to improve the targeting efficiency of drug nanocarriers taking advantage of high binding efficacy and target selectivity of antibodies for specific cell receptors. However, the therapeutic implications of nanoconjugation have been poorly considered. In this study, half-chain fragments of the anti-EGFR mAb cetuximab were conjugated to colloidal nanoparticles originating stable nanoconjugates that were investigated as surrogates of therapeutic mAbs in triple negative breast cancer (TNBC). Three TNBC cell lines were selected according to EGFR expression, which regulates activation of MAPK/ERK and PI3K/Akt pathways, and to distinctive molecular profiling including KRAS, PTEN, and BRCA1 mutations normally associated with diverse sensitivity to treatment with cetuximab. The molecular mechanisms of action of nanoconjugated half-chain mAb, including cell targeting, interference with downstream signaling pathways, proliferation, cell cycle, and apoptosis, along with triggering of ADCC response, were investigated in detail in sensitive and resistant TNBC cells. We found that half-chain mAb nanoconjugation was able to enhance the therapeutic efficacy and improve the target selectivity against sensitive, but unexpectedly also resistant, TNBC cells. Viability assays and signaling transduction modulation suggested a role of BRCA1 mutation in TNBC resistance to cetuximab alone, whereas its effect could be circumvented using half-chain cetuximab nanoconjugates, suggesting that nanoconjugation not only improved the antibody activity but also exerted different mechanisms of action. Our results provide robust evidence of the potential of half-chain antibody nanoconjugates in the treatment of TNBC, which could offer a new paradigm for therapeutic antibody administration, potentially allowing improved curative efficiency and reduced minimal effective dosages in both sensitive and resistant tumors.

A Novel Indocyanine Green Fluorescence-Guided Video-Assisted Technique for Sentinel Node Biopsy in Breast Cancer.

BACKGROUND: The equipment to detect indocyanine green (ICG) fluorescence for sentinel lymph node (SLN) biopsy in breast cancer is not widely accessible nor optimal. The fluorescence appears as a poorly defined white shine on a black background, and dimmed lighting is required. The aim of this study was to assess the feasibility, accuracy and healthcare costs of a novel approach for SLN biopsy by a video-assisted ICG-guided technique. METHODS: The technique for detecting SLN was radioisotope (RI) in 194 cases, video-assisted ICG-guided in 70 cases and a combined method in 71 cases. In the video-assisted ICG group, a full HD laparoscopic system equipped with xenon lamps was used for a laser-free detection of ICG within a colored and magnified high-resolution image. RESULTS: Detection of ICG fluorescence using a laparoscope with a near-infrared filter provided a highly defined and colored image during SLN biopsy. SLN was identified in 100% of patients in all groups. Multiple SLNs were identified in 0.5% of RI patients, in 12.9% of ICG patients and in 14.1% of ICG + RI patients (p < 0.0001). In ICG + RI group, 95.1% of lymph nodes were radioactive and 92.7% were fluorescent. Operative times and healthcare costs were equivalent between groups. CONCLUSIONS: Video-assisted ICG-guided technique is a feasible and surgeon-friendly method for SLN biopsy, with equivalent efficacy compared to RI, providing an accurate staging of the axilla.

Sentinel node biopsy in ductal carcinoma in situ of the breast: Never justified?

Sentinel lymph node biopsy for ductal carcinoma in situ (DCIS) of the breast is not standard of care. However, nodal involvement for DCIS patients is reported. Aim of our study was to identify preoperative features predictive of nodal involvement in DCIS patients. We have retrospectively reviewed 175 patients with a preoperative diagnosis of DCIS following a vacuum-assisted breast biopsy, and undergoing surgery with sentinel node biopsy. Variables distribution was compared between patients upstaged to invasive cancer at final pathology and patients with a confirmed DCIS, and between positive vs negative sentinel node patients. Univariate and multivariate analyses were performed for risk of a positive node. Lymph node biopsy was positive in 13 (7.4%) patients, with 8 (61.5%) macrometastases and 5 (38.5%) micrometastases. In these patients, Breast Imaging Reporting and Data System (BI-RADS) index >4 (OR 4.69, 95% CI 1.282-17.224, P = .02), lesion extension ≥20 mm (OR 4.25, 95% CI 1.255-14.447, P = .02), multifocal disease (OR 4.12, 95% CI 0.987-17.174, P = .05), comedo type (OR 3.54, 95% CI 1.044-11.969, P = .04), and upstaging (OR 4.56, 95% CI 1.080-19.249, P = .04) were all predictive of nodal involvement, although upstaging could not be predicted preoperatively. By multivariate analysis, the only independent factor predictive for positive sentinel node was multifocal disease (OR 5.14, 95% CI 1.015-26.066, P < .05). A preoperative diagnosis of DCIS, also including advanced biopsy systems such as vacuum-assisted breast biopsy, may be not always sufficient to exclude patients from sentinel node biopsy. DCIS patients with associated BI-RADS >4, lesion extension ≥20 mm, comedo type, and above all multifocal disease should be considered for axillary evaluation.

Cavity Shaving Reduces Involved Margins and Reinterventions Without Increasing Costs in Breast-Conserving Surgery: A Propensity Score-Matched Study.

BACKGROUND: Currently, reinterventions for involved margins after breast-conserving surgery remain common. The aim of this study was to assess the capability of the cavity shave margins (CSM) technique to reduce positive margin rates and reoperations compared with simple lumpectomy (SL). The impact of CSM on the various biological portraits of breast cancer and costs were also investigated. METHODS: A retrospective review of 976 consecutive patients from a single center was performed; 164 patients underwent SL and 812 received CSM. All patients were treated with an oncoplastic approach. and involved margins and reoperations were compared for each group. To avoid selection bias, propensity score-matched analysis was performed before applying a logistic regression model. Main outcomes were reanalyzed for each biological portrait, and surgery and hospitalization costs for SL and CSM were compared. RESULTS: Clear margins were found in 98.3% of patients in the CSM group versus 74.4% of patients in the SL group (p < 0.001). The reoperation rate was 18.9% in the SL group and 1.9% in the CSM group (p < 0.001). After propensity score-matched logistic regression, odds ratio (OR) for positive final margin status was 6.2 (95% confidence interval [CI] 2.85-13.46; p < 0.001) without CSM, while OR for reintervention was 5.46 (95% CI 2.21-13.46; p < 0.001). CSM significantly reduced positive margins and reexcisions for Luminal A, Luminal B, and triple-negative breast cancers (p < 0.001, p < 0.001, and p = 0.0137, respectively). SL had higher global costs compared with CSM: €193,630.6 versus €177,830 for 100 treated patients (p = 0.009). CONCLUSIONS: CSM reduces reexcisions, mainly in luminal breast cancers, without increasing costs.

RPTPα controls epithelial adherens junctions, linking E-cadherin engagement to c-Src-mediated phosphorylation of cortactin.

Epithelial junctions are fundamental determinants of tissue organization, subject to regulation by tyrosine phosphorylation. Homophilic binding of E-cadherin activates tyrosine kinases, such as Src, that control junctional integrity. Protein tyrosine phosphatases (PTPs) also contribute to cadherin-based adhesion and signaling, but little is known about their specific identity or functions at epithelial junctions. Here, we report that the receptor PTP RPTPα (human gene name PTPRA) is recruited to epithelial adherens junctions at the time of cell-cell contact, where it is in molecular proximity to E-cadherin. RPTPα is required for appropriate cadherin-dependent adhesion and for cyst architecture in three-dimensional culture. Loss of RPTPα impairs adherens junction integrity, as manifested by defective E-cadherin accumulation and peri-junctional F-actin density. These effects correlate with a role for RPTPα in cellular (c)-Src activation at sites of E-cadherin engagement. Mechanistically, RPTPα is required for appropriate tyrosine phosphorylation of cortactin, a major Src substrate and a cytoskeletal actin organizer. Expression of a phosphomimetic cortactin mutant in RPTPα-depleted cells partially rescues F-actin and E-cadherin accumulation at intercellular contacts. These findings indicate that RPTPα controls cadherin-mediated signaling by linking homophilic E-cadherin engagement to cortactin tyrosine phosphorylation through c-Src.