Treatment of Breast Cancer-Related Lymphedema with Adipose-Derived Regenerative Cells and Fat Grafts: A Feasibility and Safety Study

Breast fat grafting and cancer: a systematic review of the science behind enhancements and concerns

Background

Autologous fat transfer (AFT) is gaining popularity in breast surgery, offering a natural-looking and minimally invasive approach for augmentation, reconstruction, and contouring. However, concerns about its impact on breast cancer necessitate an understanding of the interplay between transplanted adipose-derived stem cells (ADSCs) and the breast tissue microenvironment. Renowned for regeneration, ADSCs raise questions about their role in cancer promotion. This systematic review delves into the complex relationship between AFT and breast cancer, exploring how ADSCs may influence development, growth, and metastasis.

Methods

A systematic search of electronic databases, including PubMed, Embase, and BVS was conducted to identify relevant studies. The search strategy employed a combination of keywords, including "breast augmentation", "fat grafting", "breast enhancement", "mammoplasty", "cancer", "neoplasm" and related terms. Two reviewers independently screened titles and abstracts. Full-text articles were then retrieved for further evaluation based on their potential contribution to the review objectives.

Results

Two hundred and forty records were identified. Among these, 104 duplicates were removed, resulting in 136 reports available for title and abstract screening. Subsequently, 54 papers were deemed potentially eligible for inclusion, and all reports were retrieved.

Conclusions

In vitro studies reveal ADSCs dual role in breast cancer, influencing proliferation, migration, and drug resistance through complex signaling pathways. Animal studies highlight distinct ADSC subpopulations impacting tumor growth via direct interactions and extracellular vesicle cargo. In vivo, ADSC-enriched fat grafting is generally safe, showing no increased cancer recurrence risk compared to other methods. Notably, cases of invasive breast carcinoma warrant special attention. ADSC-enriched fat grafts exhibit potential benefits in graft retention and survival rates. Despite promising evidence, further studies are needed to comprehensively understand the intricate relationship between ADSCs and breast cancer for optimized clinical applications and potential therapeutic innovations.

Safety and Potential Effect of Intrauterine Infusion of Autologous Adipose Tissue-Derived Regenerative Cells in Patients With Implantation Failure: A Pilot Study

BACKGROUND

Implantation failure due to thin endometrium has emerged as a major cause of infertility. In this study, we aimed to assess the safety and preliminary efficacy of adipose tissue-derived regenerative cells (ADRCs), a source of adipose-derived stem cells, in infertility patients with implantation failure.

METHODS

Five infertile women with implantation failure despite artificial reproductive technology were enrolled in this study and treated with ADRCs via the intrauterine route. The primary outcome was the incidence of adverse events. Additional outcomes were endometrial thickness after ADRC treatment and pregnancy success after embryo transfer.

RESULTS

There were no adverse events in any patient. There was no elevation of white blood cell count, C-reactive protein, or D-dimer levels. There was a significant difference in endometrial thickness in the secretory phase before versus after intrauterine transplantation of ADRCs (3.8 ± 1.3 mm versus 8.8 ± 2.8 mm, respectively; p<0.05). A gestational sac and fetal heartbeat were detected on transvaginal ultrasound in two of five patients.

CONCLUSION

Intrauterine infusion of autologous ADRCs is a simple and safe procedure that may ameliorate the endometrial microenvironment in infertile women with implantation failure.

[Research advances on stem cell-based treatments in animal studies and clinical trials of lymphedema]

Objective

To summarize the progress of the roles and mechanisms of various types of stem cell-based treatments and their combination therapies in both animal studies and clinical trials of lymphedema.

Methods

The literature on stem cell-based treatments for lymphedema in recent years at home and abroad was extensively reviewed, and the animal studies and clinical trials on different types of stem cells for lymphedema were summarized.

Results

Various types of stem cells have shown certain effects in animal studies and clinical trials on the treatment of lymphedema, mainly through local differentiation into lymphoid endothelial cells and paracrine cytokines with different functions. Current research focuses on two cell types, adipose derived stem cells and bone marrow mesenchymal stem cells, both of which have their own advantages and disadvantages, mainly reflected in the therapeutic effect of stem cells, the difficulty of obtaining stem cells and the content in vivo. In addition, stem cells can also play a synergistic role in combination with other treatments, such as conservative treatment, surgical intervention, cytokines, biological scaffolds, and so on. However, it is still limited to the basic research stage, and only a small number of studies have completed clinical trials.

Conclusion

Stem cells have great transformation potential in the treatment of lymphedema, but there is no unified standard in the selection of cell types, the amount of transplanted cells, and the timing of transplantation.

Progenitor Cell Sources for 3D Bioprinting of Lymphatic Vessels and Potential Clinical Application

The lymphatic system maintains tissue fluid homeostasis and it is involved in the transport of nutrients and immunosurveillance. It also plays a pivotal role in both pathological and regenerative processes. Lymphatic development in the embryo occurs by polarization and proliferation of lymphatic endothelial cells from the lymph sacs, that is, lymphangiogenesis. Alternatively, lymphvasculogenesis further contributes to the formation of lymphatic vessels. In adult tissues, lymphatic formation rarely occurs under physiological conditions, being restricted to pathological processes. In lymphvasculogenesis, progenitor cells seem to be a source of lymphatic vessels. Indeed, mesenchymal stem cells, adipose stem cells, endothelial progenitor cells, and colony-forming endothelial cells are able to promote lymphatic regeneration by different mechanisms, such as direct differentiation and paracrine effects. In this review, we summarize what is known on the diverse stem/progenitor cell niches available for the lymphatic system, emphasizing the potential that these cells hold for lymphatic tissue engineering through 3D bioprinting and their translation to clinical application.

Recent Advances in Therapeutic Modalities Against Breast Cancer-Related Lymphedema: Future Epigenetic Landscape

Background: Lymphedema is a significant postsurgical complication observed in the majority of breast cancer patients. These multifactorial etiopathogenesis have a significant role in the development of novel diagnostic/prognostic biomarkers and the development of novel therapies. This review aims to ascertain the epigenetic alterations that lead to breast cancer-related lymphedema (BCRL), multiple pathobiological events, and the underlying genetic predisposing factors, signaling cascades pertinent to the lapses in effective prognosis/diagnosis, and finally to develop a suitable therapeutic regimen. Methods and Results: We have performed a literature search in public databases such as PubMed, Medline, Google Scholar, National Library of Medicine and screened several published reports. Search words such as epigenetics to induce BCRL, prognosis/diagnosis, primary lymphedema, secondary lymphedema, genetic predisposing factors for BRCL, conventional therapies, and surgery were used in these databases. This review described several epigenetic-based predisposing factors and the pathophysiological consequences of BCRL, which affect the overall quality of life, and the interplay of these events could foster the progression of lymphedema in breast cancer survivors. Prognosis/diagnostic and therapy lapses for treating BCRL are highly challenging due to genetic and anatomical variations, alteration in the lymphatic vessel contractions, and variable expression of several factors such as vascular endothelial growth factor (VEGF)-E and vascular endothelial growth factor receptor (VEGFR) in breast cancer survivors. Conclusion: We compared the efficacy of various conventional therapies for treating BCRL as a multidisciplinary approach. Further substantial research is required to decipher underlying signaling epigenetic pathways to develop chromatin-modifying therapies pertinent to the multiple etiopathogenesis to explore the correlation between the disease pathophysiology and novel therapeutic modalities to treat BCRL.

Extracellular Vesicles from Adipose-Derived Stem Cells Relieve Extremity Lymphedema in Mouse Models

BACKGROUND

Transplantation of adipose-derived mesenchymal stem cells (ADSCs) has been reported to improve the severity of chronic lymphedema. Extracellular vesicles (EVs) derived from mesenchymal stem cells have been reported to exert effects such as the promotion of angiogenesis, suppression of inflammation, and regeneration of damaged organs. In this study, the authors show that lymphangiogenesis was induced by EVs derived from ADSCs and reveal the therapeutic potential of these EVs for the treatment of lymphedema.

METHODS

The authors examined the in vitro effects of ADSC-EVs to lymphatic endothelial cells (LECs). Next, they conducted an in vivo analysis of ADSC-EVs to mouse lymphedema models. Bioinformatics analysis was also performed to evaluate the implications of the altered microRNA expression.

RESULTS

The authors showed that ADSC-EVs promoted the proliferation, migration, and tube formation of LECs, and the gene expression of lymphatic markers was elevated in the ADSC-EV-treated group. Notably, a mouse lymphedema model revealed that legs treated with ADSC-EVs had markedly improved edema, with increased numbers of capillary vessels and lymphatic channels. Bioinformatics analysis revealed that ADSC-EV-associated microRNAs, such as miR-199a-3p, miR-145-5p, miR-143-3p, miR-377-3p, miR-100-3p, miR-29a-3p, miR-495-3p, and miR-29c-3p, targeted mouse double minute 2 homolog, which contributed to the stability of hypoxia-inducible factor 1α and resulted in angiogenesis and lymphangiogenesis in LECs.

CONCLUSIONS

The present study showed lymphangiogenic effects of ADSC-EVs, which will lead to new treatment options for chronic lymphedema. Cell-free therapy with EVs has fewer potential risks, such as poor engraftment efficiency and potential tumor formation, than stem cell transplantation and could be a promising tool for patients with lymphedema.

CLINICAL RELEVANCE STATEMENT

This study may open up new possibilities for novel therapies for lymphedema.

CD31 defines a subpopulation of human adipose-derived regenerative cells with potent angiogenic effects

Cellular heterogeneity represents a major challenge for regenerative treatment using freshly isolated Adipose Derived Regenerative Cells (ADRCs). Emerging data suggest superior efficacy of ADRCs as compared to the ex vivo expanded and more homogeneous ADRCs (= ASCs) for indications involving (micro)vascular deficiency, however, it remains unknown which ADRC cell subtypes account for the improvement. Surprisingly, we found regarding erectile dysfunction (ED) that the number of injected CD31+  ADRCs correlated positively with erectile function 12 months after one bolus of autologous ADRCs. Comprehensive in vitro and ex vivo analyses confirmed superior pro-angiogenic and paracrine effects of human CD31+ enriched ADRCs compared to the corresponding CD31- and parent ADRCs. When CD31+, CD31- and ADRCs were co-cultured in aortic ring- and corpus cavernous tube formation assays, the CD31+  ADRCs induced significantly higher tube development. This effect was corroborated using conditioned medium (CM), while quantitative mass spectrometric analysis suggested that this is likely explained by secretory pro-angiogenic proteins including DKK3, ANGPT2, ANAX2 and VIM, all enriched in CD31+  ADRC CM. Single-cell RNA sequencing showed that transcripts of the upregulated and secreted proteins were present in 9 endothelial ADRC subsets including endothelial progenitor cells in the heterogenous non-cultured ADRCs. Our data suggest that the vascular benefit of using ADRCs in regenerative medicine is dictated by CD31+  ADRCs.

Therapeutic Lymphangiogenesis Is a Promising Strategy for Secondary Lymphedema

Secondary lymphedema is caused by lymphatic insufficiency (lymphatic drainage failure) following lymph node dissection during the surgical treatment or radiation therapy of breast or pelvic cancer. The clinical problems associated with lymphedema are reduced quality of life in terms of appearance and function, as well as the development of skin ulcers, recurrent pain, and infection. Currently, countermeasures against lymphedema are mainly physical therapy such as lymphatic massage, elastic stockings, and skin care, and there is no effective and fundamental treatment with a highly recommended grade. Therefore, there is a need for the development of a fundamental novel treatment for intractable lymphedema. Therapeutic lymphangiogenesis, which has been attracting attention in recent years, is a treatment concept that reconstructs the fragmented lymphatic network to recover lymphatic vessel function and is revolutionary to be a fundamental cure. This review focuses on the translational research of therapeutic lymphangiogenesis for lymphedema and outlines the current status and prospects in the development of therapeutic applications.

Enhancement of Lymphangiogenesis by Human Mesenchymal Stem Cell Sheet

Preparation of human mesenchymal stem cell (hMSC) suspension for lymphedema treatment relies on conventional enzymatic digestion methods, which severely disrupts cell-cell and cell-extracellular matrix (ECM) connections, and drastically impairs cell retention and engraftment after transplantation. The objective of the present study is to evaluate the ability of hMSC-secreted ECM to augment lymphangiogenesis by using an in vitro coculturing model of hMSC sheets with lymphatic endothelial cells (LECs) and an in vivo mouse tail lymphedema model. Results demonstrate that the hMSC-secreted ECM augments the formation of lymphatic capillary-like structure by a factor of 1.2-3.6 relative to the hMSC control group, by serving as a prolymphangiogenic growth factor reservoir and facilitating cell regenerative activities. hMSC-derived ECM enhances MMP-2 mediated matrix remodeling, increases the synthesis of collagen IV and laminin, and promotes lymphatic microvessel-like structure formation. The injection of rat MSC sheet fragments into a mouse tail lymphedema model confirms the benefits of the hMSC-derived ECM by stimulating lymphangiogenesis and wound closure.

Emerging Anti-Inflammatory Pharmacotherapy and Cell-Based Therapy for Lymphedema

Secondary lymphedema is a common complication of lymph node dissection or radiation therapy for cancer treatment. Conventional therapies such as compression sleeve therapy, complete decongestive physiotherapy, and surgical therapies decrease edema; however, they are not curative because they cannot modulate the pathophysiology of lymphedema. Recent advances reveal that the activation and accumulation of CD4+ T cells are key in the development of lymphedema. Based on this pathophysiology, the efficacy of pharmacotherapy (tacrolimus, anti-IL-4/IL-13 antibody, or fingolimod) and cell-based therapy for lymphedema has been demonstrated in animal models and pilot studies. In addition, mesenchymal stem/stromal cells (MSCs) have attracted attention as candidates for cell-based lymphedema therapy because they improve symptoms and decrease edema volume in the long term with no serious adverse effects in pilot studies. Furthermore, MSC transplantation promotes functional lymphatic regeneration and improves the microenvironment in animal models. In this review, we focus on inflammatory cells involved in the pathogenesis of lymphedema and discuss the efficacy and challenges of pharmacotherapy and cell-based therapies for lymphedema.

Clinical Experience with Compression Taping to Treat Seroma After Breast Cancer Surgery: A Medical Device Clinical Study

OBJECTIVE

To evaluate the safety of compressive taping in patients with seroma secondary to breast cancer surgery.

METHODS

This study was a nonrandomized clinical study of medical devices applied to women indicated for seroma aspiration puncture after breast cancer surgery in a public reference hospital in Brazil. The intervention consisted of applying compressive taping over the seroma fluctuation area and maintained for 5 days. Evaluated outcomes comprised dermal changes caused by taping, subjective symptoms reported during the intervention period, and percent change in the punctured volume before and after the intervention.

RESULTS

A total of 35 women (mean age, 56.7 ± 12.2 years) were included. Most presented with an advanced disease stage (≥IIB; 62.9%). Although a 28.6% incidence of dermal changes caused by taping was observed, an average reduction in the aspirated volume of -28.2 mL was identified (95% confidence interval, -48.3 to -8.0; P = .008). Treatment adherence was high (91.4%), and most patients reported satisfaction with the treatment (85.7%).

CONCLUSIONS

The use of compressive taping on seroma areas can be considered safe, is well accepted by patients, and might be used as a noninvasive treatment option for seroma developing after breast cancer surgery.

Treatment of Fistulizing Perianal Crohn's Disease by Autologous Microfat Enriched With Adipose-Derived Regenerative Cells

In this pilot study, short-term efficacy and safety of fat graft enriched with Adipose-Derived Regenerative Cells (ADRC) in the treatment of Crohn’s high anal fistula was evaluated. Clinical fistula healing was achievable in 75% of cases, by a single treatment.

Adipose tissue-derived microvascular fragments promote lymphangiogenesis in a murine lymphedema model

Chronic lymphedema after cancer treatment is common and there is still no cure for this disease. We herein investigated the lymphangiogenic capacity of adipose tissue-derived microvascular fragments (MVF), which contain stem cells and lymphatic vessel fragments. Secondary lymphedema was induced in the hindlimbs of C57BL/6J mice. Green fluorescence protein (GFP)+ MVF were isolated from transgenic C57BL/6Tg (CAG-EGFP)1Osb/J mice, suspended in collagen hydrogel, and injected in the lymphadenectomy defect of wild-type animals. This crossover model allowed the detection of MVF-derived blood and lymphatic vessels after transplantation. The MVF group was compared with animals receiving collagen hydrogel only or a sham intervention. Lymphangiogenic effects were analyzed using volumetry, magnetic resonance (MR) lymphography, histology, and immunohistochemistry. MVF injection resulted in reduced hindlimb volumes when compared to non-treated controls. MR lymphography revealed lymphatic regeneration with reduced dermal backflow after MVF treatment. Finally, MVF transplantation promoted popliteal angiogenesis and lymphangiogenesis associated with a significantly increased microvessel and lymphatic vessel density. These findings indicate that MVF transplantation represents a promising approach to induce therapeutic lymphangiogenesis.

Cell therapy as a treatment of secondary lymphedema: a systematic review and meta-analysis

Background

Lymphedema, the accumulation of interstitial fluid caused by poor lymphatic drainage, is a progressive and permanent disease with no curative treatment. Several studies have evaluated cell-based therapies in secondary lymphedema, but no meta-analysis has been performed to assess their efficacy.

Methods

We conducted a systematic review and meta-analysis of all available preclinical and clinical studies, with assessment of their quality and risk of bias.

Results

A total of 20 articles using diverse cell types were selected for analysis, including six clinical trials and 14 pre-clinical studies in three species. The meta-analysis showed a positive effect of cell-based therapies on relevant disease outcomes (quantification of edema, density of lymphatic capillaries, evaluation of the lymphatic flow, and tissue fibrosis). No significant publication bias was observed.

Conclusion

Cell-based therapies have the potential to improve secondary lymphedema. The underlying mechanisms remain unclear. Due to relevant heterogeneity between studies, further randomized controlled and blinded studies are required to substantiate the use of these novel therapies in clinical practice.

Use of adipose-derived stem cells in lymphatic tissue engineering and regeneration

The potential to differentiate into different cell lines, added to the easy and cost-effective method of extraction, makes adipose-derived stem cells (ADSCs) an object of interest in lymphedema treatment. Our study’s goal was to conduct a comprehensive systematic review of the use of ADSCs in lymphatic tissue engineering and regeneration. On July 23, 2019, using PubMed/MEDLINE, Cochrane Clinical Answers, Cochrane Central Register of Controlled Trials, and Embase databases, we conducted a systematic review of published literature on the use of ADSCs in lymphatic tissue engineering and regeneration. There were no language or time frame limitations, and the following search strategy was applied: ((Adipose stem cell) OR Adipose-derived stem cell)) AND ((Lymphedema) OR Breast Cancer Lymphedema). Only original research manuscripts were included. Fourteen studies fulfilled the inclusion criteria. Eleven studies were experimental (in vitro or in vivo in animals), and only three were clinical. Publications on the topic demonstrated that ADSCs promote lymphangiogenesis, and its effect could be enhanced by modulation of vascular endothelial growth factor-C, interleukin-7, prospero homeobox protein 1, and transforming growth factor-β1. Pilot clinical studies included 11 patients with breast cancer-related lymphedema, and no significant side effects were present at 12-month follow-up. Literature on the use of ADSCs in lymphatic tissue engineering and regeneration demonstrated promising data. Clinical evidence is still in its infancy, but the scientific community agrees that ADSCs can be useful in regenerative lymphangiogenesis. Data collected in this review indicate that unprecedented advances in lymphedema treatment can be anticipated in the upcoming years.

Pilot Study of Anti-Th2 Immunotherapy for the Treatment of Breast Cancer-Related Upper Extremity Lymphedema

Recent studies suggest that Th2 cells play a key role in the pathology of secondary lymphedema by elaborating cytokines such as IL4 and IL13. The aim of this study was to test the efficacy of QBX258, a monoclonal IL4/IL13 neutralizing antibody, in women with breast cancer-related lymphedema (BCRL). We enrolled nine women with unilateral stage I/II BCRL and treated them once monthly with intravenous infusions of QBX258 for 4 months. We measured limb volumes, bioimpedance, and skin tonometry, and analyzed the quality of life (QOL) using a validated lymphedema questionnaire (Upper Limb Lymphedema 27, ULL-27) before treatment, immediately after treatment, and 4 months following treatment withdrawal. We also obtained 5 mm skin biopsies from the normal and lymphedematous limbs before and after treatment. Treatment was well-tolerated; however, one patient with a history of cellulitis developed cellulitis during the trial and was excluded from further analysis. We found no differences in limb volumes or bioimpedance measurements after drug treatment. However, QBX258 treatment improved skin stiffness (p < 0.001) and improved QOL measurements (Physical p < 0.05, Social p = 0.01). These improvements returned to baseline after treatment withdrawal. Histologically, treatment decreased epidermal thickness, the number of proliferating keratinocytes, type III collagen deposition, infiltration of mast cells, and the expression of Th2-inducing cytokines in the lymphedematous skin. Our limited study suggests that immunotherapy against Th2 cytokines may improve skin changes and QOL of women with BCRL. This treatment appears to be less effective for decreasing limb volumes; however, additional studies are needed.

Tissue Engineering Strategies for Cancer-Related Lymphedema

Tissue engineering has witnessed remarkable advancement in various fields of medicine and has the potential of revolutionizing the management of lymphedema. Combining approaches of biotechnology with the evolving understanding of lymphangiogenesis may offer promising treatment modalities for patients suffering from lymphedema. The strategies to lymphatic vessels tissue engineer can be grouped into four main categories: Delivery of chemokines, cytokines, and other growth factors to induce lymphangiogenesis; cell-based approach using lymphatic endothelial cells or stem-cells; scaffold-based tissue engineering; or a combination of these. This review will summarize the current approach to cancer-related lymphedema and advances in lymphatic tissue engineering strategies and the challenges facing the regeneration of lymphatic vasculature, particularly in an oncologic setting.

Engineering the Lymphatic Network: A Solution to Lymphedema

Secondary lymphedema is a life-long disorder characterized by chronic tissue swelling and inflammation that obstruct interstitial fluid circulation and immune cell trafficking. Regenerating lymphatic vasculatures using various strategies represents a promising treatment for lymphedema. Growth factor injection and gene delivery have been developed to stimulate lymphangiogenesis and augment interstitial fluid resorption. Using bioengineered materials as growth factor delivery vehicles allows for a more precisely targeted lymphangiogenic activation within the injured site. The implantation of prevascularized lymphatic tissue also promotes in situ lymphatic capillary network formation. The engineering of larger scale lymphatic tissues, including lymphatic collecting vessels and lymph nodes constructed by bioengineered scaffolds or decellularized animal tissues, offers alternatives to reconnecting damaged lymphatic vessels and restoring lymph circulation. These approaches provide lymphatic vascular grafting materials to reimpose lymphatic continuity across the site of injury, without creating secondary injuries at donor sites. The present work reviews molecular mechanisms mediating lymphatic system development, approaches to promoting lymphatic network regeneration, and strategies for engineering lymphatic tissues, including lymphatic capillaries, collecting vessels, and nodes. Challenges of advanced translational applications are also discussed.

Adipose-derived regenerative cells and lipotransfer in alleviating breast cancer-related lymphedema: An open-label phase I trial with 4 years of follow-up

Patients with breast cancer‐related lymphedema (BCRL) have reduced quality of life and arm function. Current treatments are palliative, and treatments improving lymphedema are lacking. Preclinical studies have suggested that adipose‐derived regenerative cells (ADRCs) can alleviate lymphedema. We, therefore, aimed to assess whether ADRCs can alleviate lymphedema in clinical reality with long‐term follow‐up. We treated 10 patients with BCRL using ADRCs and a scar‐releasing lipotransfer to the axillary region, and all patients were followed 1, 3, 6, 12, and 48 months after treatment. The primary endpoint was change in arm volume. Secondary endpoints were safety, change in lymphedema symptoms, quality of life, lymphedema‐associated cellulitis, and conservative treatment use. There was no significant decrease in BCRL volume after treatment. However, self‐reported upper extremity disability and arm heaviness and tension improved. Six patients reduced their use of conservative BCRL treatment. Five patients felt that their BCRL had improved substantially, and four of these would redo the treatment. We did not observe any cases of locoregional breast cancer recurrence. In this phase I study with 4 years of follow‐up, axillary delivered ADRCs and lipotransfer were safe and feasible and improved BCRL symptoms and upper extremity function. Randomized controlled trials are needed to confirm the results of this study.

Paracrine effect of human adipose-derived stem cells on lymphatic endothelial cells

Aim: The proposal of this study was to evaluate, in vitro, the potential paracrine effect of human adipose-derived stem cells (hASCs) to promote lymphangiogenesis in lymphatic endothelial cells isolated from rat diaphragmatic lymphatic vessels. Materials & methods: ELISA on VEGFA, VEGFC and IL6 in hASC-conditioned medium; LYVE1 immunostaining; and gene expression of PROX1, VEGFR3, VEGFC, VEGFA and IL6 were the methods used. Results: In 2D culture, hASC-conditioned medium was able to promote lymphatic endothelial cell survival, maintenance of endothelial cobblestone morphology and induction to form a vessel-like structure. Conclusion: The authors' results represent in vitro evidence of the paracrine effect of hASCs on lymphatic endothelial cells, suggesting the possible role of hASC-conditioned medium in developing new therapeutic approaches for lymphatic system-related dysfunction such as secondary lymphedema.

Therapeutic Potential of Mesenchymal Stem Cells for Postmastectomy Lymphedema: A Literature Review

Upper limb lymphedema is one of the most common complications after breast cancer surgery and radiotherapy. Despite various physical therapy and surgical options available, the impaired lymph fluid drainage may be progressive due to lymphatic vascular insufficiency making treatment more difficulty. Stem cell therapy provides a promising alternative in the treatment of various chronic diseases. The wide applicability of cell therapy has been reviewed throughout literature. This review provides an overview of recent progress in the therapeutic effect of adult stem cells for primary and secondary lymphedema after breast surgery in preclinical studies and clinical cases. We start with a brief introduction about the pathophysiological mechanisms of postmastectomy lymphedema. Regarding existing treatments, we systematically summarize the benefits and limitations of recent progress. Because of their multidirectional differentiation potential and growth factor secretion, stem cell therapy shows promising results in the management of light to severe lymphedema. Increasing evidences have demonstrated a noticeable reduction in postmastectomy lymphedema and increased lymph-angiogenesis after specific stem cell therapy. Current data suggests that stem cell therapy in lymphedema treatment provides reversal of pathological reorganization associated with lymphedema progression. Finally, we propose potential strategies for overcoming the challenges in the development of multipotent progenitor cells for the treatment and prevention of lymphedema in clinical practice.

Adipose-derived stem cell therapy shows promising results for secondary lymphedema

Lymphedema is mainly identified by progressive soft tissue swelling in impaired lymphatic system. Secondary lymphedema attributed to cancer therapy, parasite infection, and trauma remains a serious global disease. Patients with lymphedema suffer swelling, pain, and fatigue, with the dysfunction of the deformed extremities reducing the quality of life and increasing the risk of infection and lymphangiosarcoma. Adipose-derived stem cells (ADSCs) possess prominent regenerative potential to differentiate into multilineage cells, and produce various lymphangiogenic factors, making ADSC therapy a promising approach for lymphedema. The development of lymphedema consists of local inflammation, the fibrosis of lymphatic vessels, and the deposition of adipose fat. Existing animal models do not mimic the chronic inflammation environment, therefore suitable models are required in further studies. Some signal pathways and molecular mechanisms in physiological and pathological lymphagiogenesis remain unclear. In previous animal and human trials, ADSC therapy reduced edema in varying degrees. A larger number of trials with larger samples and longer follow-up periods are required to verify the efficiency and feasibility of ADSC therapy. ADSCs are of easy availability and immune exemption, making them a candidate for lymphedema treatment. Whether ADSCs enhance malignant characteristics or trigger the malignant change deserves further exploration and study before ADSC therapy can be made widely available.

Application and prospect of adipose stem cell transplantation in treating lymphedema

BACKGROUND

Lymphedema is a chronic, debilitating and incurable disease that affects 0.13%-2% of the global population. Emerging evidence indicates that adipose-derived stem cells (ADSCs) might serve as suitable seed cells for lymphatic tissue engineering and lymphedema therapy.

AIM

To summarize applications of ADSCs for treating lymphedema in both animal studies and clinical trials.

METHODS

A systematic search was performed on four databases – PubMed, Clinicaltrials.gov, the evidence-based Cochrane Library, and OVID – using the following search string: (“lymphedema” or “lymphoedema” or “lymphangiogenesis”) and (“adipose-derived stem cells” or “adipose-derived stromal cells” or “adipose-derived regenerative cells”). A manual search was performed by skimming the references of relevant studies. Animal studies and clinical trials using adipose-derived cells for the treatment of any kind of lymphedema were included.

RESULTS

A total of eight research articles published before November 2019 were included for this analysis. Five articles focused on animal studies and another three focused on clinical trials. ADSC transplantation therapy was demonstrated to be effective against lymphedema in all studies. The animal studies found that coadministration of ADSCs and controlled-release vascular endothelial growth factor-C or platelet-rich plasma could improve the effectiveness of ADSC therapy. Three sequential clinical trials were conducted on breast cancer-related lymphedema patients, and all showed favorable results.

CONCLUSION

ADSC-based therapy is a promising option for treating lymphedema. Large-scale, multicenter randomized controlled trials are needed to develop more effective and durable therapeutic strategies.

Adipose tissue-derived regenerative cells improve implantation of fertilized eggs in thin endometrium

Aim: Embryo implantation and subsequent pregnancy depends on endometrial thickness. To investigate potential fertility strategies for women with thin endometrium, we explored the efficacy of adipose tissue-derived regenerative cells (ADRCs) on thin endometrium and embryo implantation in a mouse model. Materials & methods: ADRCs isolated from mouse subcutaneous fat were characterized by flow cytometry. Endometrium thickness, endometrial fibrosis, embryo implantation and angiogenesis factors were evaluated in uterine cavities of ethanol-induced thin endometrium mice with ADRC transplantation. Results: ADRCs included adipose-derived stem cells and some blood vessel component cells. ADRCs improved endometrial thickness, endometrial fibrosis and embryo implantation and augmented vascular endothelial growth factor expression in the mouse uterine. Conclusion: ADRCs may be a useful therapeutic strategy to improve fertility of women with thin endometrium.

Comparison between stromal vascular fraction and adipose derived stem cells in a mouse lymphedema model

Background: Lymphedema is one of the most common complications following breast cancer. Axillary lymph node dissection and radiotherapy are two well-known risk factors resulting in either removal or damage to the lymph nodes. As stem cells are known for their regenerative capabilities, they could theoretically repair/restore the damaged lymph vessels leading to a decrease in lymphedema.Methods: We evaluated the treatment of SVF and ASC on a mouse lymphedema model. Forty-five mice were allocated into three groups containing 15 mice each. The SVF group was injected with 100 μl containing 1 × 10⁶ SVF, the ASC group with 100 μl ml containing 1 × 10⁶ ASC and the NS with 100 μl ml of NS. Volumes of the mice were assessed weekly by μCT hindlimb volumetry for a total of 8 weeks. Lymph vessel morphometry was assessed by cross-sections of both hindlimbs stained for anti-LYVE1. Lymphatic function was assessed by lymphatic clearance.Results: The volume change between the groups was non-significant throughout all 8 weeks. The immunohistochemistry showed a statistically significant difference between the hindlimbs in ASC vs. NS group p = 0.032, 95% CI [-2121, -103].Conclusion: The volume of the hindlimbs showed that treatment with SVF or ASC yielded very similar results compared to the control group when assessed after 8 weeks. In week two the biggest difference between ASC and NS was seen but the difference diminished during the 8 weeks. The secondary outcomes showed that the lymph vessel lumen decreased when treated with ASC compared to the control group. Lymphoscintigraphy yielded non-significant results.

Adipose-Derived Stem Cells Promote Intussusceptive Lymphangiogenesis by Restricting Dermal Fibrosis in Irradiated Tissue of Mice

Currently, there is no definitive treatment for lymphatic disorders. Adipose-derived stem cells (ADSCs) have been reported to promote lymphatic regeneration in lymphedema models, but the mechanisms underlying the therapeutic effects remain unclear. Here, we tested the therapeutic effects of ADSC transplantation on lymphedema using a secondary lymphedema mouse model. The model was established in C57BL/6J mice by x-irradiation and surgical removal of the lymphatic system in situ. The number of lymphatic vessels with anti-lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) immunoreactivity increased significantly in mice subjected to transplantation of 7.5 × 10⁵ ADSCs. X-irradiation suppressed lymphatic vessel dilation, which ADSC transplantation could mitigate. Proliferative cell nuclear antigen staining showed increased lymphatic endothelial cell (LEC) and extracellular matrix proliferation. Picrosirius red staining revealed normal collagen fiber orientation in the dermal tissue after ADSC transplantation. These therapeutic effects were not related to vascular endothelial growth factor (VEGF)-C expression. Scanning electron microscopy revealed structures similar to the intraluminal pillar during intussusceptive angiogenesis on the inside of dilated lymphatic vessels. We predicted that intussusceptive lymphangiogenesis occurred in lymphedema. Our findings indicate that ADSC transplantation contributes to lymphedema reduction by promoting LEC proliferation, improving fibrosis and dilation capacity of lymphatic vessels, and increasing the number of lymphatic vessels via intussusceptive lymphangiogenesis.

Lymphedema in survivors of breast cancer

The tremendous improvement of survival in patients with breast cancer can be attributed to several treatment strategies, but these strategies also lead to the occurrence of breast cancer-related lymphedema (BCRL). BRCL is regularly associated with factors such as axillary lymph node dissection and local lymph node radiotherapy and manifests as an increase of >10% in the volume of affected limbs. Being overweight or having obesity (body mass index ≥25 kg/m2), an excessive number of positive lymph nodes (>8) and capsular invasion by a tumor are additional risk factors for lymphedema. It is worth assessing the risk before surgery as this can prevent the occurrence of BCRL at the initial stage of breast cancer management. The clinical utility of many diagnostic tools and lymphedema surveillance allows early stage and even subclinical BCRL to be diagnosed, and allows real-time monitoring of the disease. The early diagnosis of BRCL allows treatment at an early stage, which is beneficial to the reduction of excess limb volume and the improvement of quality of life. At present, the major therapeutic methods of BCRL include complex decongestive therapy, pneumatic compression devices, participating in exercise, microsurgery and liposuction, each of which alleviates lymphedema effectively. No medications for treatment of BRCL have yet been developed. However, the recent findings on the success of molecular therapy in animal models may remedy this deficiency. Furthermore, the volume reduction of swollen limbs without swelling rebound by transplanting autologous stem cells has been successfully reported in some pilot studies, which may provide a new technique for treating BCRL. This review aimed to discuss the pathogenesis, clinical manifestation, risk factors, advantages and disadvantages of diagnostic tools, lymphedema surveillance and the characteristics of traditional and newly emerging BCRL treatments.

Review of preclinical and clinical studies of using cell-based therapy for secondary lymphedema

Secondary lymphedema is associated with impaired lymph fluid drainage and remains incurable. Alternatively, cell-based therapy may pave the way for lymphedema treatment. We found 11 animal and seven human studies had been conducted from 2008 to 2018. Most studies showed great potential for this treatment modality. Emerging studies have focused on novel techniques, such as coupling cell therapy with lymph node transfer, or adding growth factors to cell therapy.

Adipose-derived regenerative cells and fat grafting for treating breast cancer-related lymphedema: Lymphoscintigraphic evaluation with 1 year of follow-up

BACKGROUND

Breast cancer-related lymphedema (BCRL) is a feared late complication. Treatment options are lacking at present. Recent studies have suggested that mesenchymal stromal cells can alleviate lymphedema. Herein, we report the results from the first human pilot study with adipose-derived regenerative cells (ADRCs) for treating BCRL with 1 year of follow-up.

MATERIAL AND METHODS

We included 10 patients with BCRL. ADRCs were injected directly into the axillary region together with a scar-releasing fat grafting procedure. Primary endpoint was change in arm volume. Secondary endpoints were change in patient-reported outcomes, changes in lymph flow, and safety.

RESULTS

During follow-up, no significant change in volume was noted. Patient-reported outcomes improved significantly with time. Five patients reduced their use of conservative management. Quantitative lymphoscintigraphy did not improve on the lymphedema-affected arms. ADRCs were well tolerated, and only minor transient adverse events related to liposuction were noted.

CONCLUSIONS

In this pilot study, a single injection of ADRCs improved lymphedema based on patient-reported outcome measures, and there were no serious adverse events during the follow-up period. Lymphoscintigraphic evaluation showed no improvement after ADRC treatment. There was no change in excess arm volume. Results of this trial need to be confirmed in randomized clinical trials.

New and Emerging Treatments for Lymphedema

Although nonoperative and operative treatments for lymphedema (LE) are well established, these procedures typically provide only partial relief from limb swelling, functional impairment, and the risk of cellulitis. The lack of a cure for LE, however, is due to an incomplete understanding of the underlying pathophysiological mechanisms, and current research efforts are focusing on elucidating these processes to provide new, targeted therapies for this prevalent disease for which there is no cure. This article reviews the current literature regarding the pathophysiological mechanisms that underlie LE, as well as new and emerging therapies for the condition.