Autologous stem cells for the treatment of post-mastectomy lymphedema: a pilot study

Effects of a lymphedema prevention program based on the theory of knowledge-attitude-practice on postoperative breast cancer patients: A randomized clinical trial

BACKGROUND

Breast cancer-related lymphedema (BCRL) is one of the common postoperative complications that severely affects the functions of the arm and quality of life. Since lymphedema is difficult to treat and prone to recurrence, early prevention of lymphedema is crucial.

METHODS

Patient diagnosed with breast cancer (N = 108) were randomized to the intervention (n = 52) or control group (n = 56). In the intervention group, patients were provided the lymphedema prevention program based on the theory of knowledge-attitude-practice during the perioperative period and the first three chemotherapy sessions (mainly includes health education, seminars, knowledge manuals, sports guidance, peer education, and WeChat group).The limb volume, handgrip strength, arm function, and quality of life were measured in all patients at the baseline, 9 weeks (T1), and 18 weeks (T2) after surgery.

RESULTS

The incidence of lymphedema in the Intervention group was numerically lower than in the control group after implementing the lymphedema prevention program, but the difference was not statistically significant (T1: 1.9% vs. 3.8%, p = 1.000; T2: 3.6% vs. 7.1%, p = 0.744). However, compared with the control group, the intervention group showed there was less deterioration in handgrip strength (T1 [t = -2.512, p < 0.05] and T2 [t = -2.538, p < 0.05]), improved postoperative upper limb dysfunction (T1 [t = 3.087, p < 0.05] and T2 [t = 5.399, p < 0.05]) and less deterioration in quality of life (T1 [p < 0.05] and T2 [p < 0.05]).

CONCLUSION

Although the investigated lymphedema prevention program improved arm function and quality of life, it did not reduce the incidence of lymphedema in postoperative breast cancer patients.

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.

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.

A systematic review of pharmacologic and cell-based therapies for treatment of lymphedema (2010-2021)

BACKGROUND

Lymphedema describes the accumulation of interstitial fluid that results from lymphatic failure. Lymphedema can be of primary or secondary origin and has been estimated to affect 200 million people worldwide. Secondary lymphedema is commonly due to damage to the lymphatic vessels after surgical procedures. Treatments include compression bandaging and exercise regimens. However, at present, no pharmacologic therapy has been approved. We performed a systematic review of randomized controlled trials (RCTs) that had investigated pharmacologic and cell-based therapies for secondary lymphedema.

METHODS

We searched the databases MEDLINE, Embase, and ClinicalTrials.gov from January 2010 to May 2021. Only RCTs that had investigated pharmacologic and/or cell-based therapies for secondary lymphedema were eligible for inclusion. Those studies that had examined only active filarial infection were excluded. Two of us (J.W., S.T.) independently screened the studies for eligibility.

RESULTS

We identified eight RCTs that met the inclusion criteria. Overall, the studies were of poor quality with a high risk of bias. Ketoprofen demonstrated promising improvements in skin thickness and tissue histopathologic scores. Some evidence was found to suggest that doxycycline might be beneficial for nonfilarial secondary lymphedema, and a single, small RCT demonstrated that selenium might also confer some benefit. Neither synbiotics nor platelet-rich plasma resulted in reduced lymphedema volumes or symptom severity. Also, although bone marrow-derived stem cells resulted in improved symptom scores, no significant volume reduction was detected. Although positive results were demonstrated in trials investigating benzopyrones, previous meta-analyses have cast doubt on their efficacy. No two studies assessed the same intervention; thus, we could not perform a meta-analysis.

CONCLUSIONS

Although the results from some studies appeared promising, the available evidence at present is insufficient for any pharmacologic or cell-based therapy for patients with secondary lymphedema. Furthermore, large, high-quality RCTs are required before treatment recommendations will be possible.

Therapeutic Potential of Endothelial Progenitor Cells in Pulmonary Diseases

Compromised alveolar development and pulmonary vascular remodeling are hallmarks of pediatric lung diseases such as bronchopulmonary dysplasia (BPD) and alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV). Although advances in surfactant therapy, corticosteroids, and anti-inflammatory drugs have improved clinical management of preterm infants, still those who suffer with severe vascular complications lack viable treatment options. Paucity of the alveolar capillary network in ACDMPV causes respiratory distress and leads to mortality in a vast majority of ACDMPV infants. The discovery of endothelial progenitor cells (EPCs) in 1997 brought forth the paradigm of postnatal vasculogenesis and hope for promoting vascularization in fragile patient populations, such as those with BPD and ACDMPV. The identification of diverse EPC populations, both hematopoietic and nonhematopoietic in origin, provided a need to identify progenitor cell selective markers which are linked to progenitor properties needed to develop cell-based therapies. Focusing to the future potential of EPCs for regenerative medicine, this review will discuss various aspects of EPC biology, beginning with the identification of hematopoietic, nonhematopoietic, and tissue-resident EPC populations. We will review knowledge related to cell surface markers, signature gene expression, key transcriptional regulators, and will explore the translational potential of EPCs for cell-based therapy for BPD and ACDMPV. The ability to produce pulmonary EPCs from patient-derived induced pluripotent stem cells (iPSCs) in vitro, holds promise for restoring vascular growth and function in the lungs of patients with pediatric pulmonary disorders.

Advances in Lymphedema

Lymphedema is a common, complex, and inexplicably underappreciated human disease. Despite a history of relative neglect by health care providers and by governmental health care agencies, the last decade has seen an explosive growth of insights into, and approaches to, the problem of human lymphedema. The current review highlights the significant advances that have occurred in the investigative and clinical approaches to lymphedema, particularly over the last decade. This review summarizes the progress that has been attained in the realms of genetics, lymphatic imaging, and lymphatic surgery. Newer molecular insights are explored, along with their relationship to future molecular therapeutics. Growing insights into the relationships among lymphedema, obesity, and other comorbidities are important to consider in current and future responses to patients with lymphedema.

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.

Wnt Signaling Regulates the Lymphatic Endothelial Transdifferentiation of Adipose-Derived Stromal Cells In Vitro

Lymphedema is a chronic, progressive disease that causes pain as well as heavy economic burdens to patients. Reconstruction of the impaired lymphatic system is the key to treat lymphedema. Currently, there is no cure, but mesenchymal stromal cells show promising potential for lymphatic endothelial regeneration. Adipose-derived stromal cells (ADSCs) have been proved to support lymphangiogenesis both in vivo and in vitro. However, the mechanism in vascular endothelial growth factor C-induced (VEGF-C-induced) lymphatic endothelial transdifferentiation of ADSCs remains unknown. In this study, we show a novel link between the Wingless and int-1 (Wnt) pathway and the lymphatic endothelial differentiation process. We used LiCl to activate Wnt and DKK-1 to inhibit Wnt. Compared with the Wnt inhibition group and the control groups, the Wnt activation group produced more lymphatic endothelial cell (LEC)-related mRNA and proteins. Besides, Wnt-activated ADSCs formed longer tubes in two-dimensional culture and promoted the growth of lymphatic vessels in a three-dimensional transwell ADSC-LEC co-culture system. Our results demonstrated that activation of Wnt during the lymphatic endothelial transdifferentiation of ADSCs would enhance the efficacy of VEGF-C treatment. We anticipate our assay to expand our knowledge of Wnt in cell transdifferentiation and lay a foundation for future efforts to explore a novel and effective ADSC-based therapy for lymphedema.

Biology of Lymphedema

Simple Summary

Lymphedema is a chronic, debilitating disease of the lymphatic vasculature. Although several reviews focus on the anatomy and physiology of the lymphatic system, this review provides an overview of the lymphatic vasculature and, moreover, of lymphatic system dysfunction and lymphedema. Further, we aim at advancing the knowledge in the area of lymphatic system function and how dysfunction of the lymphatic system—as seen in lymphedema—affects physiological systems, such as the cardiovascular system, and how those might be modulated by lymphedema therapy.

Abstract

This narrative review portrays the lymphatic system, a poorly understood but important physiological system. While several reviews have been published that are related to the biology of the lymphatic system and lymphedema, the physiological alternations, which arise due to disturbances of this system, and during lymphedema therapy, are poorly understood and, consequently, not widely reported. We present an inclusive collection of evidence from the scientific literature reflecting important developments in lymphedema research over the last few decades. This review aims at advancing the knowledge on the area of lymphatic system function as well as how system dysfunction, as seen in lymphedema, affects physiological systems and how lymphedema therapy modulates these mechanisms. We propose that future studies should aim at investigating, in-detail, aspects that are related to fluid regulation, hemodynamic responses, and endothelial and/or vascular changes due to lymphedema and lymphedema therapy.

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.

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.

Effects of mobilized peripheral blood stem cells on treatment of primary lower extremity lymphedema

OBJECTIVE

Lymphedema is a chronic debilitating disease characterized by the accumulation of fluid in the extremities as a result of lymphatic system impairment. Current treatments fail to restore the functionality and structural integrity of the lymphatic vessels lost in this condition. In this study, autologous mobilized peripheral blood stem cell transplantation was used and its potential efficacy and safety were evaluated in treating this condition.

METHODS

Ten patients with primary lymphedema in the lower extremity received granulocyte-colony stimulating factor subcutaneously for 4 days, to stimulate stem cell mobilization, after which 200 to 250 mL of blood was drawn from each patient and used to collect stem cells. Mobilized stem cells were counted by flow cytometry with International Society of Hematotherapy and Graft Engineering method. In two sessions, 3 weeks apart, these stem cells were injected subcutaneously in the affected limb at approximately 80 points, along the lymphatic vessels. Each patient was followed for 6 months, during which changes in the limb volume and circumference were measured. Lymphangiogenesis was evaluated by biopsy, the lymphoscintigraphic transport index was calculated using Lymphoscintigraphy, and quality of life was surveyed.

RESULTS

In this study, patients received on average 9.5 ± 6.8 × 10⁸ mononuclear cells (which divided into 2 × 10⁶ CD34⁺ cells for each session) in two sessions. The volume of the lower limbs decreased in 60% of patients. One patient showed a slight increase in the volume of lower limbs and three showed no change. The average limb volume was 4469.41 ± 1760.71 cm³, which on average differed from the average initial limb volume by 232.88 ± 392.53 cm³. Quality of life was reported as slightly increased in 60% of patients. The lymphoscintigraphic transport index suggested improvement in 60% of the patients. Likewise, tissue samples showed a 60% increase in lymphatic vessels.

CONCLUSIONS

Subcutaneous injection of autologous hematopoietic stem cells harvested from peripheral blood into patients with primary lower limb lymphedema is feasible, potentially effective, and without serious adverse effects. However, a larger scale study with more patients is needed to validate our results. Last, to increase the effectiveness of this treatment, the optimal dose of cells injected and the requirement for additional growth factors need further study.

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.

Local pharmacological induction of angiogenesis: Drugs for cells and cells as drugs

The past decades have seen significant advances in pro-angiogenic strategies based on delivery of molecules and cells for conditions such as coronary artery disease, critical limb ischemia and stroke. Currently, three major strategies are evolving. Firstly, various pharmacological agents (growth factors, interleukins, small molecules, DNA/RNA) are locally applied at the ischemic region. Secondly, preparations of living cells with considerable bandwidth of tissue origin, differentiation state and preconditioning are delivered locally, rarely systemically. Thirdly, based on the notion, that cellular effects can be attributed mostly to factors secreted in situ, the cellular secretome (conditioned media, exosomes) has come into the spotlight. We review these three strategies to achieve (neo)angiogenesis in ischemic tissue with focus on the angiogenic mechanisms they tackle, such as transcription cascades, specific signalling steps and cellular gases. We also include cancer-therapy relevant lymphangiogenesis, and shall seek to explain why there are often conflicting data between in vitro and in vivo. The lion's share of data encompassing all three approaches comes from experimental animal work and we shall highlight common technical obstacles in the delivery of therapeutic molecules, cells, and secretome. This plethora of preclinical data contrasts with a dearth of clinical studies. A lack of adequate delivery vehicles and standardised assessment of clinical outcomes might play a role here, as well as regulatory, IP, and manufacturing constraints of candidate compounds; in addition, completed clinical trials have yet to reveal a successful and efficacious strategy. As the biology of angiogenesis is understood well enough for clinical purposes, it will be a matter of time to achieve success for well-stratified patients, and most probably with a combination of compounds.

Surgical interventions for the prevention or treatment of lymphoedema after breast cancer treatment

BACKGROUND

Breast cancer is the most common type of cancer amongst women worldwide, and one distressing complication of breast cancer treatment is breast and upper-limb lymphoedema. There is uncertainty regarding the effectiveness of surgical interventions in both the prevention and management of lymphoedema affecting the arm after breast cancer treatment.

OBJECTIVES

1. To assess and compare the efficacy of surgical interventions for the prevention of the development of lymphoedema (LE) in the arm after breast cancer treatment.2. To assess and compare the efficacy of surgical interventions for the treatment of established LE in the arm after breast cancer treatment.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group's Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the WHO International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov for all prospectively registered and ongoing trials on 2 November 2017. Reference lists of included studies were also handsearched by three review authors for additional eligible trials.

SELECTION CRITERIA

All randomised controlled trials (RCTs) comparing a surgical intervention for the prevention or treatment of lymphoedema of the arm after breast cancer treatment to either standard intervention, placebo intervention, or another surgical intervention were included. Patients of both sexes and all ages who have had treatment for their breast cancer were considered. No limits were applied to language or study location. Three authors independently determined the eligibility of each study.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data for each included study using a pre-designed data extraction pro forma and used Cochrane's 'risk of bias' tool for assessing risk of bias. Dichotomous variables were analysed using the Mantel-Haenszel method to estimate risk ratios (RRs). Differences in continuous variables were expressed as mean differences (MDs). GRADE was used to assess the certainty of the evidence provided by the included studies.

MAIN RESULTS

Two studies involving 95 participants examined surgical interventions for preventing breast cancer-related lymphoedema. Both studies evaluated the efficacy of the lymphaticovenular anastomosis technique as part of a preventative management protocol. Both studies were deemed to be at unclear risk of bias overall. Statistical variation between the studies was low, which increases the reliability of the evidence. However, the two studies were conducted in the same centre. Lymphaticovenular anastomosis appears to result in a reduction in the incidence of lymphoedema compared to nonoperative management with a risk ratio of 0.20 (95% CI 0.06 to 0.63, P = 0.006; 95 participants; low-certainty evidence). The RCTs did not evaluate any of the secondary outcomes.One study involving 36 participants evaluated the effectiveness of vascularised lymph node transfer for treating breast cancer-related lymphoedema. The trial was deemed to be at unclear risk of bias. For participants suffering from stage 2 lymphoedema, the evidence suggested reductions in limb volume (MD -39.00%, 95% CI -47.37% to -30.63%, very low-certainty evidence), pain scores (MD -4.16, 95% CI -5.17 to -3.15, very low-certainty evidence), heaviness sensation (MD -4.27, 95% CI -5.74 to -2.80, very low-certainty evidence), mean number of infections/year (MD -1.22, 95% CI -2.00 to -0.44, very low-certainty evidence), and an improvement in overall function scores (MD -3.77, 95% CI -4.89 to -2.65, very low-certainty evidence) for those who had undergone vascularised lymph node transfer compared to those who had undergone no treatment.

AUTHORS' CONCLUSIONS

There is low-certainty evidence that lymphaticovenular anastomosis is effective in preventing the development of lymphoedema after breast cancer treatment based on the findings from two studies. One study providing very low-certainty evidence found that vascularised lymph node transfer is an efficacious option in the treatment of established stage 2 lymphoedema related to breast cancer. Important secondary outcomes in this review were rarely reported in the included studies. More high-quality RCTs are required to further elucidate the effectiveness of surgical interventions in the prevention and treatment of lymphoedema after breast cancer treatment. At the time of this review, no ongoing trials on this topic were identified.

Recent Advances in Endothelial Progenitor Cells Toward Their Use in Clinical Translation

Since the discovery of Endothelial Progenitor Cells (EPC) by Asahara and colleagues in 1997, an increasing number of preclinical studies have shown that EPC based therapy is feasible, safe, and efficacious in multiple disease states. Subsequently, this has led to several, mainly early phase, clinical trials demonstrating the feasibility and safety profile of EPC therapy, with the suggestion of efficacy in several conditions including ischemic heart disease, pulmonary arterial hypertension and decompensated liver cirrhosis. Despite the use of the common term “EPC,” the characteristics, manufacturing methods and subset of the cell type used in these studies often vary significantly, rendering clinical translation challenging. It has recently been acknowledged that the true EPC is the endothelial colony forming cells (ECFC). The objective of this review was to summarize and critically appraise the registered and published clinical studies using the term “EPC,” which encompasses a heterogeneous cell population, as a therapeutic agent. Furthermore, the preclinical data using ECFC from the PubMed and Web of Science databases were searched and analyzed. We noted that despite the promising effect of ECFC on vascular regeneration, no clinical study has stemmed from these preclinical studies. We showed that there is a lack of information registered on www.clinicaltrials.gov for EPC clinical trials, specifically on cell culture methods. We also highlighted the importance of a detailed definition of the cell type used in EPC clinical trials to facilitate comparisons between trials and better understanding of the potential clinical benefit of EPC based therapy. We concluded our review by discussing the potential and limitations of EPC based therapy in clinical settings.

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.

Lymphedema: Pathogenesis and Novel Therapies

Lymphedema affects up to 1 in 6 patients who undergo treatment for a solid tumor in the United States. Its prevalence has increased as more effective oncologic therapies have improved patient survival, but there remains no definitive cure. Recent research has elucidated new details in the pathogenesis of the disease and has demonstrated that it is fundamentally an immunologic process that ultimately results in inflammation, fibroadipose deposition, impaired lymphangiogenesis, and dysfunctional lymphatic pumping. These findings have allowed for the development of novel medical and surgical therapies that may potentially alter the standard of care for a disease that has largely been treated by compression. This review seeks to provide an overview of the emerging therapies and how they can be utilized for effective management of lymphedema.

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

Breast cancer‐related lymphedema (BCRL) is a debilitating late complication with a lack of treatment opportunities. Recent studies have suggested that mesenchymal stromal cells can alleviate lymphedema. Herein, we report the results from the first human pilot study with freshly isolated adipose‐derived regenerative cells (ADRC) for treating lymphedema with 6 months follow‐up. Ten BCRL patients were included. ADRC was injected directly into the axillary region, which was combined with a scar‐releasing fat graft procedure. Primary endpoints were change in arm volume. Secondary endpoints were change in patient reported outcome and safety. The study is registered with ClinicalTrials.gov (NCT02592213). During follow‐up, a small volume reduction was noted but was not significant. Five patients reduced their use of conservative management. Patient‐reported outcomes improved significantly over time. ADRCs were well tolerated and only minor transient adverse events related to liposuction were noted. In this pilot study, a single injection of ADRC improved lymphedema based on patient‐reported outcome measures, and there were no serious adverse events in the 6 months follow‐up period. In addition, half of the patients reduced their use of conservative management. ADRC therapy is a promising interventional therapy for alleviating lymphedema, but results need to be confirmed in randomized clinical trials. Stem Cells Translational Medicine2017;6:1666–1672

Current Treatments for Breast Cancer-Related Lymphoedema: A Systematic Review

Background and objective: Breast cancer-related lymphoedema (BCRL) is a disabling complication with long term impact on quality on life after breast cancer treatment. Its management remains a major challenge for patients and health care professionals; the goal of this overview was to summarize effects of different treatment strategies for patients with BCRL. Methods: A thorough search was undertaken to allow a systematic review or meta-analysis of treatments for BCRL. Two investigators independently selected studies and abstracted the data. Results: Combined physical therapy (CPT) with different combinations of surgery, oral pharmaceuticals, low-level laser therapy, weight reduction, mesenchymal stem cell therapy, kinesio tex taping, and acupuncture might be effective in reducing lymphoedema, but exercise demonstrated no obvious benefit. The results of direct comparisons showed CPT might be more effective than standard physiotherapy (ST). Manual lymphatic drainage (MLD) may not offer additional benefits to ST for swelling reduction, but could facilitate compression bandaging. MLD seemed to have similar effects with self-administered simple lymphatic drainage (SLD) or using an intermittent pneumatic compression pump (IPC). IPC might also not be associated with additional effectiveness for CPT. Efficacy of stem cell therapy vs. compression sleeve or CPT, as well as the effects of daflon and coumarin could not be established. Conclusion: Although many treatments for BCRL might reduce lymphoedema volume, their effects were not well established. The quality of many of the original studies in the included reviews was not optimal, so that in future randomized control trials are a high priority.

Therapy modalities to reduce lymphoedema in female breast cancer patients: a systematic review and meta-analysis

The aim of the present study was to evaluate the effects of compression bandages, sleeves, intermittent pneumatic compression (IPC) and active exercise on the reduction of breast cancer-related lymphoedema (BCRL). A systematic literature search up to the year January 2016 was performed in CINAHL, Cochrane Register of Controlled Trials, Embase, International Clinical Trials Registry Platform (WHO), PEDro and PubMed. Inclusion criteria were (1) RCTs, (2) reported adequate statistics for meta-analysis, (3) English or German language. Exclusion criteria were (1) effects of drugs, hormonal, radiation and surgical procedures, (2) studies with children, (3) non-breast cancers, lower extremity oedema, (4) impact on fatigue only, diets or sexually transmitted diseases, (5) cost-analysis only and (6) non-carcinogenic syndromes or (7) prevention of breast cancer. After scoring the methodological quality of the selected studies, data concerning volume reduction of the oedema swelling were extracted. Thirty-two studies were included in this systematic review. Nine studies were selected for the RCT-based studies and 19 studies were included in the pre-post studies-based random-effects meta-analyses. All conclusions should be taken with precautions because of the insufficient quality of the selected papers. Exercise seems beneficial in reducing oedema volume in BCRL. IPC seems beneficial in helping to reduce the oedema volume in the acute phase of treatment. Compression sleeves do not aid in the volume reduction in the acute phase; however, they do prevent additional swelling.

Cell-Assisted Lipotransfer Using Autologous Adipose-Derived Stromal Cells for Alleviation of Breast Cancer-Related Lymphedema

: Lymphedema is one of the most frequent side effects following cancer treatment, and treatment opportunities for it are currently lacking. Stem cell therapy has been proposed as a possible novel treatment modality. This study was the first case in which freshly isolated adipose-derived stromal cells were used to treat lymphedema. Treatment was given as a cell-assisted lipotransfer in which 4.07 × 10(7) cells were injected with 10 ml of lipoaspirate in the axillary region. Four months after treatment, the patient reported a great improvement in daily symptoms, reduction in need for compression therapy, and volume reduction of her affected arm. There were no adverse events. The outcome for this patient provides support for the potential use of cellular therapy for lymphedema treatment. We have begun a larger study to further test the feasibility and safety of this procedure (ClinicalTrials.gov Identifier NCT02592213).

SIGNIFICANCE

Lymphedema is a very debilitating side effect of cancer treatment and has very few treatment options. Stem cell therapy has the potential to change the treatment paradigm from a conservative to a more curative approach. Freshly isolated, autologous, adipose-derived stromal cells were combined with a fat-graft procedure to treat lymphedema. The treated patient had great improvement in daily symptoms, a reduced need for compression therapy, and a reduction in arm volume after 4 months. There were no adverse events. The use of cellular therapy for lymphedema treatment is supported by this patient's outcome. A phase II study has begun to further test its feasibility and safety.

Stem Cell Therapies in Clinical Trials: Progress and Challenges

Clinical investigations using stem cell products in regenerative medicine are addressing a wide spectrum of conditions using a variety of stem cell types. To date, there have been few reports of safety issues arising from autologous or allogeneic transplants. Many cells administered show transient presence for a few days with trophic influences on immune or inflammatory responses. Limbal stem cells have been registered as a product for eye burns in Europe and mesenchymal stem cells have been approved for pediatric graft versus host disease in Canada and New Zealand. Many other applications are progressing in trials, some with early benefits to patients.

Concise Review: Endothelial Progenitor Cells in Regenerative Medicine: Applications and Challenges

Endothelial progenitor cells (EPCs) are currently being studied as candidate cell sources for revascularization strategies. Significant advances have been made in understanding the biology of EPCs, and preclinical studies have demonstrated the vasculogenic, angiogenic, and beneficial paracrine effects of transplanted EPCs in the treatment of ischemic diseases. Despite these promising results, widespread clinical acceptance of EPCs for clinical therapies remains hampered by several challenges. The present study provides a concise summary of the different EPC populations being studied for ischemic therapies and their known roles in the healing of ischemic tissues. The challenges and issues surrounding the use of EPCs and the current strategies being developed to improve the harvest efficiency and functionality of EPCs for application in regenerative medicine are discussed.

SIGNIFICANCE

Endothelial progenitor cells (EPCs) have immense clinical value for cardiovascular therapies. The present study provides a concise description of the EPC subpopulations being evaluated for clinical applications. The current major lines of investigation involving preclinical and clinical evaluations of EPCs are discussed, and significant gaps limiting the translation of EPCs are highlighted. The present report could be useful for clinicians and clinical researchers with interests in ischemic therapy and for basic scientists working in the related fields of tissue engineering and regenerative medicine.

Adipose-derived stem cells promote proliferation, migration, and tube formation of lymphatic endothelial cells in vitro by secreting lymphangiogenic factors

Adipose-derived stem cells (ADSCs) are a promising new therapeutic modality for several diseases and have been applied to various clinical fields because of their multidifferentiation potential and capacity for growth-factor secretion. Recently, 2 in vivo studies showed ADSCs to have potential applications in lymphedema therapy. However, it remains unclear whether ADSCs have direct effects on lymphatic endothelial cells (LECs). In this study, human LECs were treated with murine ADSC-derived conditioned media. Changes in LEC proliferation, migration, and tube formation were assessed by WST-8 assay, transwell chamber assay, and Matrigel-based tube formation assay, respectively, with recombinant human vascular endothelial growth factor-C used as a positive control. Additionally, the expression of several lymphangiogenic factors in ADSCs was examined by quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Factors secreted by ADSCs induced LEC proliferation, migration, and tube formation more potently than recombinant human vascular endothelial growth factor-C. We confirmed by quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay that some of the lymphangiogenic factors of ADSCs were dramatically up-regulated under serum-starved conditions. These data indicate that ADSCs could directly contribute to lymphangiogenesis via secretory factors in vitro and may thus provide a therapeutic modality for patients with lymphedema.

Putting evidence into practice: cancer-related lymphedema

Cancer-related lymphedema is a progressive and chronic syndrome of abnormal swelling and multiple symptoms resulting from cancer treatment. Even with modern medical advances, lymphedema remains a major health problem affecting thousands of cancer survivors. To provide healthcare professionals with evidence-based clinical practice guidelines for lymphedema treatment and management, a systematic review was conducted to evaluate 75 selected articles from 2009-2014 by the Oncology Nursing Society Putting Evidence Into Practice lymphedema team. Findings of the systematic review support complete decongestive therapy, compression bandages, and compression garments with highest evidence for best clinical practice. Weight management, full-body exercise, information provision, prevention, and early intervention protocols are likely to be effective for clinical practice. Historic recommendations for activity restriction and avoidance of aerobic and resistive exercises that limit cancer survivors' daily lives have been challenged with more evidence. Cancer survivors may not need to restrict activities such as resistive or aerobic exercises and weightlifting with gradual exercise progression. Future research should focus on providing high-level evidence using randomized clinical trials with larger samples and studying lymphedema beyond breast cancer.

Lymphoscintigraphy for the assessment of autologous stem cell implantation in chronic lymphedema

Lymphoscintigraphy is the criterion standard technique for the diagnosis of lymphedema. The authors present the images acquired before and 6 months after implantation of autologous stem cells in 2 patients with chronic lymphedema of the lower limbs. The stem cells implantations were carried out by multiple superficial and deep injections in the trajectory of the lymphatic vessels and also in the inguinal region. A volume of 0.75 to 1.00 mL of cell suspension (1.0-2.2 × 10(9) stem cells) was administered in each injection site. The anatomy and function of the lymphatic system were evaluated.

Breast cancer-related lymphedema: risk factors, prevention, diagnosis and treatment

SUMMARY 

Lymphedema is one of the late effects of breast cancer treatment that affects many breast cancer survivors. Despite an increased focus on morbidity among this survivor population, our understanding of risk reduction, prevention, diagnosis and treatment of lymphedema remain poorly understood. This article provides an overview of the current state of the research (2009–2014) on breast cancer-related lymphedema and offers future directions for research. A greater emphasis must be placed on reducing the impact of lymphedema to improve the quality of life for breast cancer survivors.

Cell-based therapy for therapeutic lymphangiogenesis

Lymphedema is a medically irreversible condition for which currently conservative and surgical therapies are either ineffective or impractical. The potential use of progenitor and stem cell-based therapies has offered a paradigm that may provide alternative treatment options for lymphatic disorders. Moreover, basic research, preclinical studies, as well as clinical trials have evaluated the therapeutic potential of various cell therapies in the field of lymphatic regeneration medicine. Among the available cell approaches, mesenchymal stem cells (MSCs) seem to be the most promising candidate mainly due to their abundant sources and easy availability as well as evitable ethical and immunological issues confronted with embryonic stem cells and induced pluripotent stem cells. In this context, the purpose of this review is to summarize various cell-based therapies for lymphedema, along with strengths and weaknesses of these therapies in the clinical application for lymphedema treatment. Particularly, we will highlight the use of MSCs for lymphatic regeneration medicine. In addition, the future perspectives of MSCs in the field of lymphatic regeneration will be discussed.

Stem cells show promising results for lymphoedema treatment--a literature review

Lymphoedema is a debilitating condition, manifesting in excess lymphatic fluid and swelling of subcutaneous tissues. Lymphoedema is as of yet still an incurable condition and current treatment modalities are not satisfactory. The capacity of mesenchymal stem cells to promote angiogenesis, secrete growth factors, regulate the inflammatory process, and differentiate into multiple cell types make them a potential ideal therapy for lymphoedema. Adipose tissue is the richest and most accessible source of mesenchymal stem cells and they can be harvested, isolated, and used for therapy in a single stage procedure as an autologous treatment. The aim of this paper was to review all studies using mesenchymal stem cells for lymphoedema treatment with a special focus on the potential use of adipose-derived stem cells. A systematic search was performed and five preclinical and two clinical studies were found. Different stem cell sources and lymphoedema models were used in the described studies. Most studies showed a decrease in lymphoedema and an increased lymphangiogenesis when treated with stem cells and this treatment modality has so far shown great potential. The present studies are, however, subject to bias and more preclinical studies and large-scale high quality clinical trials are needed to show if this emerging therapy can satisfy expectations.