Targeted therapy with propranolol and metronomic chemotherapy combination: sustained complete response of a relapsing metastatic angiosarcoma

Social Genomic Determinants of Health: Understanding the Molecular Pathways by Which Neighborhood Disadvantage Affects Cancer Outcomes

PURPOSE

Neighborhoods represent complex environments with unique social, cultural, physical, and economic attributes that have major impacts on disparities in health, disease, and survival. Neighborhood disadvantage is associated with shorter breast cancer recurrence-free survival (RFS) independent of individual-level (race, ethnicity, socioeconomic status, insurance, tumor characteristics) and health system-level determinants of health (receipt of guideline-concordant treatment). This persistent disparity in RFS suggests unaccounted mechanisms such as more aggressive tumor biology among women living in disadvantaged neighborhoods compared with advantaged neighborhoods. The objective of this article was to provide a clear framework and biological mechanistic explanation for how neighborhood disadvantage affects cancer survival.

METHODS

Development of a translational epidemiological framework that takes a translational disparities approach to study cancer outcome disparities through the lens of social genomics and social epigenomics.

RESULTS

The social genomic determinants of health, defined as the physiological gene regulatory pathways (ie, neural/endocrine control of gene expression and epigenetic processes) through which contextual factors, particularly one's neighborhood, can affect activity of the cancer genome and the surrounding tumor microenvironment to alter disease progression and treatment outcomes.

CONCLUSION

We propose a novel, multilevel determinants of health model that takes a translational epidemiological approach to evaluate the interplay between political, health system, social, psychosocial, individual, and social genomic determinants of health to understand social disparities in oncologic outcomes. In doing so, we provide a concrete biological pathway through which the effects of social processes and social epidemiology come to affect the basic biology of cancer and ultimately clinical outcomes and survival.

Congenital Vascular and Lymphatic Diseases

Over the past several centuries, the integration of contemporary medical techniques and innovative technologies, like genetic sequencing, have played a pivotal role in enhancing our comprehension of congenital vascular and lymphatic disorders. Nonetheless, the uncommon and complex characteristics of these disorders, especially considering their formation during the intrauterine stage, present significant obstacles in diagnosis and treatment. Here, we review the intricacies of these congenital abnormalities, offering an in-depth examination of key diagnostic approaches, genetic factors, and therapeutic methods.

A bleeding heart: case report and review of pericardial angiosarcoma

Primary cardiac tumors are rare. The cardiac sarcomas are the most common malignant cardiac tumors. These tumors have a dismal prognosis with an overall median survival of 25 months. Clinical features include dyspnea, arrhythmias, pericardial effusions, heart failure, and sudden cardiac death. The diagnosis is often challenging. Therefore, the cardiac imaging workup plays a central role in addition to a high clinical suspicion in the setting of atypical presentations that do not respond to standard therapies. The echocardiography, computed tomography, and cardiac MRI are crucial in clinching the diagnosis. Multimodal treatment with surgery, chemotherapy, and radiotherapy has been shown to improve outcomes, as opposed to using either of these modalities alone. We describe the case of a 30-year-old gentleman with COVID-19 infection who developed recurrent hemorrhagic pericardial effusions refractory to standard treatment and was eventually diagnosed as a case of pericardial angiosarcoma after his biopsy revealed the diagnosis and staging was performed using PET-CT-FDG scan. Our case re-emphasizes the importance of considering a malignant etiology early in the course of the disease presentation, especially in recurrent hemorrhagic effusions despite an inflammatory cytologic diagnosis of fluid. It also highlights the place for cardiac CT and MRI to ascertain the location and spread and to plan the further course of treatment. If diagnosed early, the estimated survival time can be prolonged by instituting a multimodal approach.

Guiding model-driven combination dose selection using multi-objective synergy optimization

Despite the growing appreciation that the future of cancer treatment lies in combination therapies, finding the right drugs to combine and the optimal way to combine them remains a nontrivial task. Herein, we introduce the Multi-Objective Optimization of Combination Synergy - Dose Selection (MOOCS-DS) method for using drug synergy as a tool for guiding dose selection for a combination of preselected compounds. This method decouples synergy of potency (SoP) and synergy of efficacy (SoE) and identifies Pareto optimal solutions in a multi-objective synergy space. Using a toy combination therapy model, we explore properties of the MOOCS-DS algorithm, including how optimal dose selection can be influenced by the metric used to define SoP and SoE. We also demonstrate the potential of our approach to guide dose and schedule selection using a model fit to preclinical data of the combination of the PD-1 checkpoint inhibitor pembrolizumab and the anti-angiogenic drug bevacizumab on two lung cancer cell lines. The identification of optimally synergistic combination doses has the potential to inform preclinical experimental design and improve the success rates of combination therapies. Jel classificationDose Finding in Oncology.

Repurposing of Chronically Used Drugs in Cancer Therapy: A Chance to Grasp

Despite the advancement in drug discovery for cancer therapy, drug repurposing remains an exceptional opportunistic strategy. This approach offers many advantages (faster, safer, and cheaper drugs) typically needed to overcome increased challenges, i.e., side effects, resistance, and costs associated with cancer therapy. However, not all drug classes suit a patient's condition or long-time use. For that, repurposing chronically used medications is more appealing. This review highlights the importance of repurposing anti-diabetic and anti-hypertensive drugs in the global fight against human malignancies. Extensive searches of all available evidence (up to 30 March 2023) on the anti-cancer activities of anti-diabetic and anti-hypertensive agents are obtained from multiple resources (PubMed, Google Scholar, ClinicalTrials.gov, Drug Bank database, ReDo database, and the National Institutes of Health). Interestingly, more than 92 clinical trials are evaluating the anti-cancer activity of 14 anti-diabetic and anti-hypertensive drugs against more than 15 cancer types. Moreover, some of these agents have reached Phase IV evaluations, suggesting promising official release as anti-cancer medications. This comprehensive review provides current updates on different anti-diabetic and anti-hypertensive classes possessing anti-cancer activities with the available evidence about their mechanism(s) and stage of development and evaluation. Hence, it serves researchers and clinicians interested in anti-cancer drug discovery and cancer management.

Efficacy and adverse events of anthracycline and propranolol combination in five dogs with stage 3 hemangiosarcoma

Background

Canine hemangiosarcoma (HSA), which originates from endothelial cells, is one of the most common malignant neoplasms that frequently develop metastatic lesions. Although anthracycline-based HSA treatment strategies have been widely investigated, reliable therapy for dogs with clinically advanced-stage HSA (stage 3 HSA) has not been established yet. Recently, several studies have demonstrated that propranolol, a beta-adrenergic receptor antagonist, exhibits anti-tumor effects against tumors originating from vascular endothelial cells, indicating the possibility that propranolol is a candidate adjunctive agent for anthracycline-based therapy in dogs with stage 3 HSA. This study aimed to evaluate the clinical efficacy and adverse events (AEs) of anthracycline and propranolol combination in stage 3 HSA-affected dogs.

Case Description

We retrospectively investigated five dogs diagnosed with stage 3 HSA which were administered with both anthracycline and propranolol during the same period between January 2020 and August 2021. Clinical benefit was observed in four of five HSA dogs (one of complete response, one of partial response, and two of stable disease) with gross metastatic lesions by anthracycline and propranolol combination. Notably, some or all of the metastatic lesions were reduced in two cases. In all five dogs administered with anthracycline and propranolol combination, no serious and irreversible AEs were observed.

Conclusion

Our findings demonstrate the efficacy and safety of anthracycline and propranolol combination in stage 3 HSA-affected dogs. Further studies are needed to establish treatment protocols based on anthracycline and propranolol combination for dogs with advanced HSA.

Emerging role of substance and energy metabolism associated with neuroendocrine regulation in tumor cells

Cancer is the second most common cause of mortality in the world. One of the unresolved difficult pathological mechanism issues in malignant tumors is the imbalance of substance and energy metabolism of tumor cells. Cells maintain life through energy metabolism, and normal cells provide energy through mitochondrial oxidative phosphorylation to generate ATP, while tumor cells demonstrate different energy metabolism. Neuroendocrine control is crucial for tumor cells' consumption of nutrients and energy. As a result, better combinatorial therapeutic approaches will be made possible by knowing the neuroendocrine regulating mechanism of how the neuroendocrine system can fuel cellular metabolism. Here, the basics of metabolic remodeling in tumor cells for nutrients and metabolites are presented, showing how the neuroendocrine system regulates substance and energy metabolic pathways to satisfy tumor cell proliferation and survival requirements. In this context, targeting neuroendocrine regulatory pathways in tumor cell metabolism can beneficially enhance or temper tumor cell metabolism and serve as promising alternatives to available treatments.

Repurposing Drugs in Small Animal Oncology

Repurposing drugs in oncology consists of using off-label drugs that are licensed for various non-oncological medical conditions to treat cancer. Repurposing drugs has the advantage of using drugs that are already commercialized, with known mechanisms of action, proven safety profiles, and known toxicology, pharmacokinetics and pharmacodynamics, and posology. These drugs are usually cheaper than new anti-cancer drugs and thus more affordable, even in low-income countries. The interest in repurposed anti-cancer drugs has led to numerous in vivo and in vitro studies, with some promising results. Some randomized clinical trials have also been performed in humans, with certain drugs showing some degree of clinical efficacy, but the true clinical benefit for most of these drugs remains unknown. Repurposing drugs in veterinary oncology is a very new concept and only a few studies have been published so far. In this review, we summarize both the benefits and challenges of using repurposed anti-cancer drugs; we report and discuss the most relevant studies that have been previously published in small animal oncology, and we suggest potential drugs that could be clinically investigated for anti-cancer treatment in dogs and cats.

Beta-adrenergic receptor blockade in angiosarcoma: Which beta-blocker to choose?

Beta-blockers are currently studied to improve therapeutic options for patients with angiosarcoma. However, most of these patients have no cardiovascular co-morbidity and it is therefore crucial to discuss the most optimal pharmacological properties of beta-blockers for this population. To maximize the possible effectiveness in angiosarcoma, the use of a non-selective beta-blocker is preferred based on in vitro data. To minimize the risk of cardiovascular adverse events a beta-blocker should ideally have intrinsic sympathomimetic activity or vasodilator effects, e.g. labetalol, pindolol or carvedilol. However, except for one case of carvedilol, only efficacy data of propranolol is available. In potential follow-up studies labetalol, pindolol or carvedilol can be considered to reduce the risk of cardiovascular adverse events.

Beta-blockers disrupt mitochondrial bioenergetics and increase radiotherapy efficacy independently of beta-adrenergic receptors in medulloblastoma

Background

Medulloblastoma is the most frequent brain malignancy of childhood. The current multimodal treatment comes at the expense of serious and often long-lasting side effects. Drug repurposing is a strategy to fast-track anti-cancer therapy with low toxicity. Here, we showed the ability of β-blockers to potentiate radiotherapy in medulloblastoma with bad prognosis.

Methods

Medulloblastoma cell lines, patient-derived xenograft cells, 3D spheroids and an innovative cerebellar organotypic model were used to identify synergistic interactions between β-blockers and ionising radiations. Gene expression profiles of β-adrenergic receptors were analysed in medulloblastoma samples from 240 patients. Signaling pathways were explored by RT-qPCR, RNA interference, western blotting and RNA sequencing. Medulloblastoma cell bioenergetics were evaluated by measuring the oxygen consumption rate, the extracellular acidification rate and superoxide production.

Findings

Low concentrations of β-blockers significantly potentiated clinically relevant radiation protocols. Although patient biopsies showed detectable expression of β-adrenergic receptors, the ability of the repurposed drugs to potentiate ionising radiations did not result from the inhibition of the canonical signaling pathway. We highlighted that the efficacy of the combinatorial treatment relied on a metabolic catastrophe that deprives medulloblastoma cells of their adaptive bioenergetics capacities. This led to an overproduction of superoxide radicals and ultimately to an increase in ionising radiations-mediated DNA damages.

Interpretation

These data provide the evidence of the efficacy of β-blockers as potentiators of radiotherapy in medulloblastoma, which may help improve the treatment and quality of life of children with high-risk brain tumours.

Funding

This study was funded by institutional grants and charities.

Blockade of beta-adrenergic receptors reduces cancer growth and enhances the response to anti-CTLA4 therapy by modulating the tumor microenvironment

The development of immune checkpoint inhibitors (ICI) marks an important breakthrough of cancer therapies in the past years. However, only a limited fraction of patients benefit from such treatments, prompting the search for immune modulating agents that can improve the therapeutic efficacy. The nonselective beta blocker, propranolol, which for decades has been prescribed for the treatment of cardiovascular conditions, has recently been used successfully to treat metastatic angiosarcoma. These results have led to an orphan drug designation by the European Medicines Agency for the treatment of soft tissue sarcomas. The anti-tumor effects of propranolol are suggested to involve the reduction of cancer cell proliferation as well as angiogenesis. Here, we show that oral administration of propranolol delays tumor progression of MCA205 fibrosarcoma model and MC38 colon cancer model and increases the survival rate of tumor bearing mice. Propranolol works by reducing tumor angiogenesis and facilitating an anti-tumoral microenvironment with increased T cell infiltration and reduced infiltration of myeloid-derived suppressor cells (MDSCs). Using T cell deficient mice, we demonstrate that the full anti-tumor effect of propranolol requires the presence of T cells. Flow cytometry-based analysis and RNA sequencing of FACS-sorted cells show that propranolol treatment leads to an upregulation of PD-L1 on tumor associated macrophages (TAMs) and changes in their chemokine expression profile. Lastly, we observe that the co-administration of propranolol significantly enhances the efficacy of anti-CTLA4 therapy. Our results identify propranolol as an immune modulating agent, which can improve immune checkpoint inhibitor therapies in soft tissue sarcoma patients and potentially in other cancers.

Drug Repurposing for Cancer Therapy in the Era of Precision Medicine

Drug repurposing refers to the identification of clinically approved drugs with the known safety profiles and defined pharmacokinetic properties for new indications. Despite the advances in oncology research, cancers are still associated with the most unmet medical needs. Drug repurposing has emerged as a useful approach for the search for effective and durable cancer treatment. It may also represent a promising strategy to facilitate precision cancer treatment and overcome drug resistance. The repurposing of non-cancer drugs for precision oncology effectively extends the inventory of actionable molecular targets and thus increases the number of patients who may benefit from precision cancer treatment. In cancer types where genetic heterogeneity is so high that it is not feasible to identify strong repurposed drug candidates for standard treatment, the precision oncology approach offers individual patients access to novel treatment options. For repurposed candidates with low potency, a combination of multiple repurposed drugs may produce a synergistic therapeutic effect. Precautions should be taken when combining repurposed drugs with anticancer agents to avoid detrimental drug-drug interactions and unwanted side effects. New multifactorial data analysis and artificial intelligence methods are needed to untangle the complex association of molecular signatures influencing specific cancer subtypes to facilitate drug repurposing in precision oncology.

Drug Repurposing in Oncology, an Attractive Opportunity for Novel Combinatorial Regimens

The costs of developing, validating and buying new drugs are dramatically increasing. On the other hand, sobering economies have difficulties in sustaining their healthcare systems, particularly in countries with an elderly population requiring increasing welfare. This conundrum requires immediate action, and a possible option is to study the large, already present arsenal of drugs approved and to use them for innovative therapies. This possibility is particularly interesting in oncology, where the complexity of the cancer genome dictates in most patients a multistep therapeutic approach. In this review, we discuss a) Computational approaches; b) preclinical models; c) currently ongoing or already published clinical trials in the drug repurposing field in oncology; and d) drug repurposing to overcome resistance to previous therapies.

The Use of Antihypertensive Drugs as Coadjuvant Therapy in Cancer

Cancer is a complex group of diseases that constitute the second largest cause of mortality worldwide. The development of new drugs for treating this disease is a long and costly process, from the discovery of the molecule through testing in phase III clinical trials, a process during which most candidate molecules fail. The use of drugs currently employed for the management of other diseases (drug repurposing) represents an alternative for developing new medical treatments. Repurposing existing drugs is, in principle, cheaper and faster than developing new drugs. Antihypertensive drugs, primarily belonging to the pharmacological categories of angiotensin-converting enzyme inhibitors, angiotensin II receptors, direct aldosterone antagonists, β-blockers and calcium channel blockers, are commonly prescribed and have well-known safety profiles. Additionally, some of these drugs have exhibited pharmacological properties useful for the treatment of cancer, rendering them candidates for drug repurposing. In this review, we examine the preclinical and clinical evidence for utilizing antihypertensive agents in the treatment of cancer.

The Effectiveness of Different Treatment Modalities of Cutaneous Angiosarcoma: Results From Meta-Analysis and Observational Data From SEER Database

Introduction

Cutaneous angiosarcoma (cAS) is an aggressive vascular tumor that originates from vascular or lymphatic epithelial cells. To date, the cAS literature has been limited in a small number with single-center experiences or reports due to its rarity and the optimal treatment strategy is still in dispute. This study aimed to conduct a systematic review and compare the effect of available treatments retrieved from observational studies and Surveillance, Epidemiology, and End Results (SEER) program.

Methods

The authors performed a systematic review in the PubMed, Embase and MEDLINE database identifying the researches assessing the treatment for cAS patients. Clinical and treatment information of patients who had been diagnosed with a primary cAS were also obtained from the SEER program.

Results

Thirty-two studies were eligible but only 5 of which with 276 patients were included in meta-analysis since the unclear or unavailable information. The risk ratio of 5-year death for surgery, surgery with radiotherapy and surgery with chemotherapy were 0.84, 0.96, and 0.69. Meanwhile, in SEER database, there are 291 metastatic and 437 localized patients with cAS. The localized patients receiving surgery showed a significantly worse overall survival result when compared with the surgery combined with RT: hazard ratio: 1.6, 95% confidential interval: 1.05, 2.42, P = 0.03.

Conclusion

In conclusion, our study provided a detailed picture of the effectiveness of present treatments for localized and metastatic cAS patients. The CT could be inappropriate in localized patients. For metastatic patients, the surgery combined RT was recommended compared with surgery alone since its enhanced OS prognosis. Yet, more novel-designed clinical trials with specific targeted populations and rigorous conducting are needed for a solid conclusion on which would be a better treatment strategy.

Propranolol Sensitizes Vascular Sarcoma Cells to Doxorubicin by Altering Lysosomal Drug Sequestration and Drug Efflux

Angiosarcoma is a rare cancer of blood vessel-forming cells with a high patient mortality and few treatment options. Although chemotherapy often produces initial clinical responses, outcomes remain poor, largely due to the development of drug resistance. We previously identified a subset of doxorubicin-resistant cells in human angiosarcoma and canine hemangiosarcoma cell lines that exhibit high lysosomal accumulation of doxorubicin. Hydrophobic, weak base chemotherapeutics, like doxorubicin, are known to sequester within lysosomes, promoting resistance by limiting drug accessibility to cellular targets. Drug synergy between the beta adrenergic receptor (β-AR) antagonist, propranolol, and multiple chemotherapeutics has been documented in vitro, and clinical data have corroborated the increased therapeutic potential of propranolol with chemotherapy in angiosarcoma patients. Because propranolol is also a weak base and accumulates in lysosomes, we sought to determine whether propranolol enhanced doxorubicin cytotoxicity via antagonism of β-ARs or by preventing the lysosomal accumulation of doxorubicin. β-AR-like immunoreactivities were confirmed in primary tumor tissues and cell lines; receptor function was verified by monitoring downstream signaling pathways of β-ARs in response to receptor agonists and antagonists. Mechanistically, propranolol increased cytoplasmic doxorubicin concentrations in sarcoma cells by decreasing the lysosomal accumulation and cellular efflux of this chemotherapeutic agent. Equivalent concentrations of the receptor-active S-(-) and -inactive R-(+) enantiomers of propranolol produced similar effects, supporting a β-AR-independent mechanism. Long-term exposure of hemangiosarcoma cells to propranolol expanded both lysosomal size and number, yet cells remained sensitive to doxorubicin in the presence of propranolol. In contrast, removal of propranolol increased cellular resistance to doxorubicin, underscoring lysosomal doxorubicin sequestration as a key mechanism of resistance. Our results support the repurposing of the R-(+) enantiomer of propranolol with weak base chemotherapeutics to increase cytotoxicity and reduce the development of drug-resistant cell populations without the cardiovascular and other side effects associated with antagonism of β-ARs.

Propranolol and Weekly Paclitaxel in the Treatment of Metastatic Heart Angiosarcoma

Heart angiosarcoma, the most frequent among cardiac malignancies, is an extremely rare vascular tumor known to carry a dismal prognosis. The spectrum of presenting symptoms depends on tumor’s size, its anatomic location, and its invasiveness, whereas imaging techniques including cardiac magnetic resonance are critical in the differential diagnosis between malignant and benign neoplasms. Despite there are various available systemic therapeutic regimens for advanced cardiac angiosarcomas, yet, it still remains unclear which of them offers the best survival outcome in general. We present the uncommon case of metastatic right atrium angiosarcoma in a young male patient, in which the combination of propranolol and weekly paclitaxel, as first-line treatment, showed promising activity with manageable toxicity. Given the existing strong rationale for repurposing propranolol in oncology, this therapeutic approach merits further investigation in prospective studies with heart angiosarcoma patients.

PropAngio study protocol: a neoadjuvant trial on the efficacy of propranolol monotherapy in cutaneous angiosarcoma-a proof of principle study

INTRODUCTION

Angiosarcoma is a rare and aggressive malignancy with a high metastatic potential and recurrence rate. Despite optimal treatment with surgery, with or without radiation, the prognosis remains poor and, therefore, new treatment strategies are warranted. Recently, propranolol has effectively been repurposed for the treatment of infantile haemangioma. Propranolol is a β3-sparing antagonist of the β-adrenergic receptor. In infantile haemangioma, the β1, β2 and β3 receptors are highly expressed. Angiosarcoma has several similarities with haemangioma, including its high β-adrenergic receptor expression and the supposedly important role of vascular endothelial growth factor in malignant growth. As a result, propranolol has been administered small scale in individual angiosarcoma cases with promising results. The precise effect of propranolol, however, is not yet established.

METHODS AND ANALYSIS

The goal of this neoadjuvant window of opportunity study is to prospectively evaluate the activity of propranolol monotherapy in patients with cutaneous angiosarcoma. The neoadjuvant setting provides a good opportunity to rapidly evaluate both the clinical response and histological response, without a significant delay in standard anticancer treatment. Fourteen patients with primary, recurrent or metastatic cutaneous angiosarcoma will be included. Propranolol will be administered orally in an escalating dose during 3-6 weeks, before the initiation of standard treatment. The primary endpoint is clinical response according to Response Evaluation Criteria in Solid Tumours, as measured on consecutive coloured photographs or CT/MRI. The histological response will be determined as secondary endpoint, comparing the difference in proliferation index before and after propranolol by measuring the change in immunohistochemistry staining of Ki-67. The study will be considered positive when at least three patients have a response to propranolol.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Medical Ethical Committee of the Netherlands Cancer Institute. Independent of the outcome, results of this study will be shared and submitted for publication in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NL8118; registry through the Netherlands Trial Register.

A case report of Kaposiform haemangioendothelioma; response with propranolol and steroids

Background

Kaposiform haemangioendothelioma is a rare vascular tumor and may involve skin, deep soft tissue or bone. It is a locally aggressive tumor usually seen in infants. Here we report a case of kaposiform hemagioendothelioma in a child who responded to propranolol and steroids.

Case presentation

A 3-year-old male child presented with a swelling below his right knee with characteristic violet skin lesion. There was no evidence of Kasabach–Merritt phenomenon. After no improvement with several attempts at debridement and anti-tubercular treatment; a diagnosis of Kaposiform Haemangioendothelioma was reached on the basis of overall clinical picture and histology. The child was treated with propranolol and steroids and had an excellent clinical response and a near complete resolution on imaging at 5 months.

Conclusions

These cases are often misdiagnosed and despite a delay in diagnosis have good outcomes with appropriate multimodality management. This case highlights the unique and typical characteristics of kaposiform haemangioendothelioma.

Can stress promote the pathophysiology of brain metastases? A critical review of biobehavioral mechanisms

Chronic stress can promote tumor growth and progression through immunosuppressive effects and bi-directional interactions between tumor cells and their microenvironment. β-Adrenergic receptor signaling plays a critical role in mediating stress-related effects on tumor progression. Stress-related mechanisms that modulate the dissemination of tumor cells to the brain have received scant attention. Brain metastases are highly resistant to chemotherapy and contribute considerably to morbidity and mortality in various cancers, occurring in up to 20% of patients in some cancer types. Understanding the mechanisms promoting brain metastasis could help to identify interventions that improve disease outcomes. In this review, we discuss biobehavioral, sympathetic, neuroendocrine, and immunological mechanisms by which chronic stress can impact tumor progression and metastatic dissemination to the brain. The critical role of the inflammatory tumor microenvironment in tumor progression and metastatic dissemination to the brain, and its association with stress pathways are delineated. We also discuss translational implications for biobehavioral and pharmacological interventions.

Emerging therapeutic approaches for canine sarcomas: Pushing the boundaries beyond the conventional

Sarcomas represent a group of genomically chaotic, highly heterogenous tumours of mesenchymal origin with variable mutational load. Conventional therapy with surgery and radiation therapy is effective for managing small, low-grade sarcomas and remains the standard therapeutic approach. For advanced, high-grade, recurrent, or metastatic sarcomas, systemic chemotherapy provides minimal benefit, therefore, there is a drive to develop novel approaches. The discovery of "Coley's toxins" in the 19th century, and their use to stimulate the immune system supported the application of unconventional therapies for the treatment of sarcomas. While promising, this initial work was abandoned and treatment paradigm and disease course of sarcomas was largely unchanged for several decades. Exciting new therapies are currently changing treatment algorithms for advanced carcinomas and melanomas, and similar approaches are being applied to advance the field of sarcoma research. Recent discoveries in subtype-specific cancer biology and the identification of distinct molecular targets have led to the development of promising targeted strategies with remarkable potential to change the landscape of sarcoma therapy in dogs. The purpose of this review article is to describe the current standard of care and limitations as well as emerging approaches for sarcoma therapy that span many of the most active paradigms in oncologic research, including immunotherapies, checkpoint inhibitors, and drugs capable of cellular metabolic reprogramming.

[Cutaneous angiosarcoma : Radiochemotherapy with liposomal pegylated doxorubicin]

BACKGROUND

Whilst cutaneous angiosarcoma is rare tumour which primarily affects elderly patients, its management presents a significant therapeutic challenge. Indeed, complete surgical excision is often not possible due to the location and the diffuse and extensive nature of the tumour. Therefore, current treatment strategies often include chemo- and/or radiotherapy.

METHODS

We report our experience of combined chemo- and radiotherapy in the clinical course of 6 patients with cutaneous angiosarcoma who were treated between 2007 and 2018.

RESULTS

All patients presented non-resectable tumours and were treated with radiotherapy in combination with the administration of liposomal, pegylated doxrubicin (25 mg/m² every 2 weeks). The mean duration of progression-free survival was 8 months (5-14 months), corresponding to an overall survival of 13 months (13-34 months). A partial response was seen in 4 patients and 1 patient developed progressive disease. One patient abandoned therapy after one administration. Two patients developed severe adverse events which led to termination of therapy after 1.5 months and 7 months, i.e. after 4 and 15 cycles respectively.

DISCUSSION

Combined radio- and chemotherapy with liposomal, pegylated doxorubicin is a useful therapeutic option in the management of cutaneous angiosarcoma. Given the short-lived response rate, new treatment options are urgently required.

Management of Localized Breast Angiosarcoma by North American Radiation and Medical Oncologists

INTRODUCTION

Primary breast angiosarcoma is a rare malignancy with no clinical trials to guide management. The current use of surgery, chemotherapy, and radiotherapy among North American oncologists is unknown.

PATIENTS AND METHODS

An institutional review board-approved anonymous electronic survey was distributed to 9660 practicing North American radiation and medical oncologists. Questions pertained to treatment recommendations for localized nonmetastatic primary breast angiosarcoma, as well as knowledge/use of β-blockers in angiosarcoma. The Fisher exact test was used to compare responses of medical and radiation oncologists.

RESULTS

Surgery was recommended by 95% of all respondents. Chemotherapy was recommended by over half of medical and radiation oncologists. Radiotherapy was recommended by 92% of radiation and 56% of medical oncologists. The most common treatment recommendation was a trimodal treatment, with up-front surgery followed by adjuvant chemotherapy, then by adjuvant radiotherapy. Twenty-two percent of respondents were aware of clinical data pertaining to the use of β-blockers in management of angiosarcoma, and among these respondents 69% were comfortable incorporating this treatment into standard practice.

CONCLUSION

Trimodal management of primary localized breast angiosarcoma is supported by North American radiation and medical oncologists, with the majority recommending up-front surgery followed by adjuvant chemotherapy and radiation. The recently published reports of successful use of β-blockers are not yet known among North American clinicians, but there is a great enthusiasm to incorporate these commonly prescribed medications into standard practice. These findings may greatly influence the standard of care for breast angiosarcoma treatment, particularly given the absence of Level I-supported evidence.

Regression of primary cardiac angiosarcoma and metastatic nodules following propranolol as a single agent treatment

Angiosarcoma is the most common malignant cardiac tumor. Cardiac angiosarcoma is a highly lethal neoplasm that is largely resistant to conventional anti-cancer therapy. Mean survival of patients with cardiac angiosarcoma is only 4 months, and almost all patients will succumb to the disease within 1 year. The beta blocker propranolol is an emerging therapy against angiosarcoma. When combined with conventional therapies, propranolol increases progression free and overall survival in patients with this tumor type. It is currently unknown if propranolol is capable of showing anti-cancer efficacy as a single agent therapy. We report a case of a 61 year old woman diagnosed with primary cardiac angiosarcoma and liver and lung metastases. This patient chose to decline conventional therapy, and instead was prescribed the beta blocker propranolol as a single agent treatment. After 12 months, the mediastinal mass substantially debulked and decreased in size, and the metastatic nodules stabilized or resolved with no evidence of hyper-metabolic activity on PET-CT. This is the first reported data showing long term efficacy of the beta blocker propranolol as a single agent therapy against angiosarcoma.

Propranolol for the treatment of vascular sarcomas

Vascular sarcomas are abnormal proliferations of endothelial cells. They range from benign hemangioma to aggressive angiosarcoma, and are characterized by dysregulated angiogenic signaling. Propranolol is a β-adrenergic receptor inhibitor that has demonstrated clinical efficacy in benign infantile hemangioma, and is now being used experimentally for more aggressive vascular sarcomas and other cancers. In this review, we discuss the use of propranolol in targeting these receptors in vascular tumors and other cancers.

5-HT serotonin receptors modulate mitogenic signaling and impact tumor cell viability

Symptoms of depression are present in over half of all cancer patients, and selective serotonin reuptake inhibitor (SSRI) anti-depressant medications are prescribed to nearly a quarter of these individuals in order to cope with their disease. Previous studies have provided evidence that elevated serotonin (5-HT) and serotonin receptor levels may contribute to oncogenic progression, yet little is known regarding the mechanism by which this occurs. The data demonstrated that serotonin receptor mRNAs and proteins are expressed across diverse cancer types, and that serotonin stimulation of tumor cells activates oncogenic signaling mediators including components of the AKT, CREB, GSK3, and MAPK pathways. Selective pharmacological inhibition of the seven known classes of 5-HT receptors in sarcoma and breast cancer cells resulted in dose dependent decreases in tumor cell viability, activation of the p53 DNA damage pathway, suppression of MAPK activity, and significantly reduced tumor volume in an in ovo model. Based on a retrospective clinical analysis of 419 patients diagnosed with breast cancer, we discovered that use of SSRIs was associated with a 2.3-fold increase in tumor proliferation rates for late stage patients based on their Ki-67 index (P=0.03). These data provide evidence that serotonin signaling pathways, which treating oncologists often pharmacologically target to assist cancer patients to psychologically cope with their illness, activate signaling pathways known to promote tumor growth and survival.

Non-selective beta blockers inhibit angiosarcoma cell viability and increase progression free- and overall-survival in patients diagnosed with metastatic angiosarcoma

Patients with metastatic angiosarcoma undergoing chemotherapy, radiation, and/or surgery experience a median progression free survival of less than 6 months and a median overall survival of less than 12 months. Given the aggressive nature of this cancer, angiosarcoma clinical responses to chemotherapy or targeted therapeutics are generally very poor. Inhibition of beta adrenergic receptor (β-AR) signaling has recently been shown to decrease angiosarcoma tumor cell viability, abrogate tumor growth in mouse models, and decrease proliferation rates in preclinical and clinical settings. In the current study we used cell and animal tumor models to show that β-AR antagonism abrogates mitogenic signaling and reduces angiosarcoma tumor cell viability, and these molecular alterations translated into patient tumors. We demonstrated that non-selective β-AR antagonists are superior to selective β-AR antagonists at inhibiting angiosarcoma cell viability. A prospective analysis of non- selective β-AR antagonists in a single arm clinical study of metastatic angiosarcoma patients revealed that incorporation of either propranolol or carvedilol into patients' treatment regimens leads to a median progression free and overall survival of 9 and 36 months, respectively. These data suggest that incorporation of non-selective β-AR antagonists into existing therapies against metastatic angiosarcoma can enhance clinical outcomes.

Current and Future Directions for Angiosarcoma Therapy

OPINION STATEMENT

Angiosarcomas are rare vascular neoplasms that are among the most aggressive subtypes of soft tissue sarcomas. Surgical resection is often challenging even in localized disease, as the infiltrative nature of these cancers leads to frequent local and metastatic recurrences. Cytotoxic chemotherapy, including anthracycline-based regimens and taxanes can produce significant responses in a subset of patients but durability is limited with most patients ultimately succumbing to metastatic disease. Targeted therapy with tyrosine kinase inhibitors is usually well-tolerated but prone to development of resistance. Few head-to-head trials have addressed the optimal sequence of therapies, or demonstrated conclusive benefits of one therapy over another based on clinical and etiologic factors. Novel therapies in clinical trials, including antibodies to endoglin and checkpoint inhibitors have demonstrated exciting early activity in patients with angiosarcoma. Improved understanding of the genetic heterogeneity within various angiosarcoma subtypes may identify predictive biomarkers to match patients to effective existing and future therapies. Overall, angiosarcoma patients with optimal performance status are best served in clinical trials that incorporate novel combinations of cytotoxic chemotherapy, targeted therapies, and immunotherapies.

Cutaneous angiosarcoma: update on biology and latest treatment

PURPOSE OF REVIEW

The present review aims to provide readers with the latest updates on the biology and clinical management of cutaneous angiosarcoma (cAS).

RECENT FINDINGS

The genomic alteration of cAS is heterogeneous. Mutations are enriched in the mitosis-activated kinase (MAPK) pathway. Functional analysis has identified molecules that may serve as potential markers and therapeutic targets of angiosarcoma. These molecules include survivin, HSP90, FOXM1, miR-497-5p, KCa3.1, and miR210.This body of knowledge has not yet transferred to clinical practice. The mainstay of treatment for cAS remains surgery followed by postoperative radiotherapy. The efficacy of paclitaxel as an adjuvant chemotherapy is suggested.For patients with advanced cAS, paclitaxel is the treatment of choice. There are also second-line treatment options that are supported by evidence of varying strength. A multikinase inhibitor, pazopanib, has been assessed in several studies, most of which support its efficacy for angiosarcoma. Bevacizumab monotherapy may be effective for angiosarcoma. The efficacy of eribulin mesylate and trabectedin for angiosarcoma is currently being assessed. Recent publications highlighted the role of the immune system in the biology of cAS.

SUMMARY

Future research efforts should focus on the following aspects of cAS: drug development directed at recent molecular targets, clinical trials designed specifically for patients with cAS, and the role of immunotherapy for cAS.

Use of non-selective β-blockers is associated with decreased tumor proliferative indices in early stage breast cancer

Previous studies suggest beta-adrenergic receptor (β-AR) antagonists (β-blockers) decrease breast cancer progression, tumor metastasis, and patient mortality; however the mechanism for this is unknown. Immunohistochemical analysis of normal and malignant breast tissue revealed overexpression of β1-AR and β3-AR in breast cancer. A retrospective cross-sectional study of 404 breast cancer patients was performed to determine the effect of β-blocker usage on tumor proliferation. Our analysis revealed that non-selective β-blockers, but not selective β-blockers, reduced tumor proliferation by 66% (p < 0.0001) in early stage breast cancer compared to non-users. We tested the efficacy of propranolol on an early stage breast cancer patient, and quantified the tumor proliferative index before and after treatment, revealing a propranolol-mediated 23% reduction (p = 0.02) in Ki67 positive tumor cells over a three-week period. The anti-proliferative effects of β-blockers were measured in a panel of breast cancer lines, demonstrating that mammary epithelial cells were resistant to propranolol, and that most breast cancer cell lines displayed dose dependent viability decreases following treatment. Selective β-blockers alone or in combination were not as effective as propranolol at reducing breast cancer cell proliferation. Molecular analysis revealed that propranolol treatment of the SK-BR-3 breast cancer line, which showed high sensitivity to beta blockade, led to a reduction in Ki67 protein expression, decreased phosphorylation of the mitogenic signaling regulators p44/42 MAPK, p38 MAPK, JNK, and CREB, increased phosphorylation of the cell survival/apoptosis regulators AKT, p53, and GSK3β. In conclusion, use of non-selective β-blockers in patients with early stage breast cancer may lead to decreased tumor proliferation.

Propranolol enhanced the anti-tumor effect of sunitinib by inhibiting proliferation and inducing G0/G1/S phase arrest in malignant melanoma

Both sunitinib, a multi-target tyrosine kinase inhibitor (TKI) and propranolol, a non-selective β-blocker, have proven therapeutic effects on malignant melanoma (MM). This study reports a synergistic effect of propranolol and sunitinib upon A375, P8 MM cell lines and mice xenografts. Cell viability assays detected a significant decrease of sunitinib IC50 in combination with propranolol, which was confirmed by a colony formation assay. Western blot showed that propranolol and sunitinib combination significantly down-regulated phospho-Rb, phospho-ERK, Cyclin D1, and Cyclin E, but had no effect on Bax, Bcl-2, or cleaved PARP expression. The average tumor size of propranolol and low-dose sunitinib (Sun L) combination treated mice was reduced and similar to high-dose sunitinib treated A375 xenografts. The Ki67 index was significantly reduced in propranolol and Sun L combination treated group compared with single Sun L treated group. This synergistic effect between propranolol and sunitinib to inhibit MM proliferation was through suppressing ERK/Cyclin D1/Rb/Cyclin E pathways and inducing G0/G1/S phase arrest, rather than by inducing tumor cell apoptosis.

Cutaneous angiosarcoma: a current update

Cutaneous angiosarcoma (cAS) is a rare malignant neoplasm with variable clinical presentation. Although a distinct vascular tumour, cAS shares many overlapping histopathological features with other vasoformative and epithelioid tumours or 'mimickers'. cAS shows aggressive behaviour and carries a grave prognosis, thus early diagnosis is of paramount importance to achieve the best possible outcomes. Recently, several genetic studies were conducted leading to the identification of novel molecular targets in the treatment of cAS. Herein, we present a comprehensive review of cAS with discussion of its clinical, histopathological and molecular aspects, the differential diagnosis, as well as current therapies including ongoing clinical trials.

Beta-adrenergic receptors are expressed across diverse cancers

Based largely on retrospective analyses and a handful of prospective case reports, pharmacological inhibition of the beta adrenergic receptors using beta blockers has shown clinical anti-cancer efficacy in reproductive cancers, as well as angiosarcoma and multiple myeloma. Because of the potential promise of beta blockers as an adjunct to standard anti-cancer therapy, it is imperative to identify other tumor types expressing beta adrenergic (β-AR) receptors so future preclinical and clinical studies can be directed at the most promising tumor targets. We performed immunohistochemical detection of β1-AR, β2-AR, and β3-AR across 29 of the most common human cancer types (389 tissues total) and 19 matching non-diseased controls (100 tissues total). Our analysis revealed all three β-AR receptors were expressed most strongly in melanoma relative to other cancer types. Other malignancies that revealed relatively higher levels of β-AR receptors were esophagus, pancreas, kidney, and lung cancers. Moreover, particular β-AR receptors exhibited significant overexpression in tumor tissue relative to their matching normal tissue in urogenital/reproductive malignancies including breast, endometrium, ovarian, and urothelial cancer, as well as colon, lung, and thyroid cancer. This study identifies several cancer types expressing the β-AR receptors which should be evaluated in future studies for susceptibility to beta blockade.

Rho kinase proteins display aberrant upregulation in vascular tumors and contribute to vascular tumor growth

BACKGROUND

The serine/threonine protein kinases ROCK1 and 2 are key RhoA-mediated regulators of cell shape and cytoskeletal dynamics. These proteins perform multiple functions in vascular endothelial cell physiology and are attractive targets for cancer therapy based on their roles as oncogenes and metastatic promoters. Given their critical functions in both of these processes, we hypothesized that molecular targeting of ROCK proteins would be exceedingly effective against vascular tumors such as hemangiomas and angiosarcomas, which are neoplasms composed of aberrant endothelial cells.

METHODS

In this study, we compared ROCK1 and 2 protein expression in a large panel of benign and malignant vascular tumors to that of normal vasculature. We then utilized shRNA technology to knockdown the expression of ROCK1 and 2 in SVR tumor-forming vascular cells, and evaluated tumor size and proliferation rate in a xenograft model. Finally, we employed proteomics and metabolomics to assess how knockdown of the ROCK paralogs induced alterations in protein expression/phosphorylation and metabolite concentrations in the xenograft tumors.

RESULTS

Our findings revealed that ROCK1 was overexpressed in malignant vascular tumors such as hemangioendotheliomas and angiosarcomas, and ROCK2 was overexpressed in both benign and malignant vascular tumors including hemangiomas, hemangioendotheliomas, hemangiopericytomas, and angiosarcomas. shRNA-mediated knockdown of ROCK2, but not ROCK1, in xenograft vascular tumors significantly reduced tumor size and proliferative index compared to control tumors. Proteomics and metabolomics analysis of the xenograft tumors revealed both overlapping as well as unique roles for the ROCK paralogs in regulating signal transduction and metabolite concentrations.

CONCLUSIONS

Collectively, these data indicate that ROCK proteins are overexpressed in diverse vascular tumors and suggest that specific targeting of ROCK2 proteins may show efficacy against malignant vascular tumors.

Systemic treatment in advanced soft tissue sarcoma: what is standard, what is new

For metastatic soft tissue sarcoma (STS) patients not eligible for surgery, systemic treatments, including standard chemotherapy and newer biological compounds, still play the most relevant role in the management of the disease. An anthracycline and alkylating agent combination has formed the cornerstone of chemotherapy in STS for more than 30 years, with its value over that of administration of anthracycline as a single agent still being debated. Efforts have been made to improve the activity and minimise the toxicity of the combination, as well as to explore the upfront efficacy of agents known to be active in sarcoma and to develop new biological compounds. Nevertheless, beyond the first line, evidence for medical treatment in STS is less robust and all the more driven by histology. Thus, the introduction of kinases and small molecule inhibitors in the treatment armamentarium for STS is a major achievement in this setting. Preliminary data on immunotherapy are also available and discussed in this review.

Next generation metronomic chemotherapy-report from the Fifth Biennial International Metronomic and Anti-angiogenic Therapy Meeting, 6-8 May 2016, Mumbai

The 5^th Biennial Metronomic and Anti-angiogenic Therapy Meeting was held on 6^th – 8^th May in the Indian city of Mumbai. The meeting brought together a wide range of clinicians and researchers interested in metronomic chemotherapy, anti-angiogenics, drug repurposing and combinations thereof. Clinical experiences, including many from India, were reported and discussed in three symposia covering breast cancer, head and neck cancers and paediatrics. On the pre-clinical side research into putative mechanisms of action, and the interactions between low dose metronomic chemotherapy and angiogenesis and immune responses, were discussed in a number of presentations. Drug repurposing was discussed both in terms of clinical results, particularly with respect to angiosarcoma and high-risk neuroblastoma, and in pre-clinical settings, particularly the potential for peri-operative interventions. However, it was clear that there remain a number of key areas of challenge, particularly in terms of definitions, perceptions in the wider oncological community, mechanisms of action and predictive biomarkers. While the potential for metronomics and drug repurposing in low and middle income countries remains a key theme, it is clear that there is also considerable potential for clinically relevant improvements in patient outcomes even in high income economies.

Primary Angiosarcoma of the Spleen: Rare Diagnosis with Atypical Clinical Course

Primary angiosarcoma of the spleen is a rare diagnosis with poor prognosis. Morphologically, it demonstrates conventional blood vessel differentiation. We present a case of 65-year-old female who underwent radical splenectomy for primary angiosarcoma of the spleen. After three-year disease-free interval, she was diagnosed with bone-only metastatic disease. Palliative radiotherapy and bisphosphonates kept her disease reasonably stable for another four years. After development of lung metastases, six cycles of single agent doxorubicin kept her progression-free for six years. Upon further progression in lungs, thirteen years after original diagnosis, lung biopsy confirmed metastatic splenic angiosarcoma in the lungs. She started weekly paclitaxel chemotherapy. Although splenic angiosarcoma generally carries grave prognosis, some patients may enjoy prolonged periods of disease stabilization. Durable benefit can be achieved in some patients with multimodality management. We review the literature focusing on systemic treatment for this rare tumor.

Repurposing Drugs in Oncology (ReDO)-Propranolol as an anti-cancer agent

Propranolol (PRO) is a well-known and widely used non-selective beta-adrenergic receptor antagonist (beta-blocker), with a range of actions which are of interest in an oncological context. PRO displays effects on cellular proliferation and invasion, on the immune system, on the angiogenic cascade, and on tumour cell sensitivity to existing treatments. Both pre-clinical and clinical evidence of these effects, in multiple cancer types, is assessed and summarised and relevant mechanisms of action outlined. In particular there is evidence that PRO is effective at multiple points in the metastatic cascade, particularly in the context of the post-surgical wound response. Based on this evidence the case is made for further clinical investigation of the anticancer effects of PRO, particularly in combination with other agents. A number of trials are on-going, in different treatment settings for various cancers.

Highlights from the 1st Latin American meeting on metronomic chemotherapy and drug repositioning in oncology, 27-28 May, 2016, Rosario, Argentina

Following previous metronomic meetings in Marseille (2011), Milano (2014), and Mumbai (2016), the first Latin American metronomic meeting was held in the School of Medical Sciences, National University of Rosario, Rosario, Argentina on 27 and 28 of May, 2016. For the first time, clinicians and researchers with experience in the field of metronomics, coming from different countries in Latin America, had the opportunity of presenting and discussing their work. The talks were organised in three main sessions related to experience in the pre-clinical, and clinical (paediatric and adult) areas. The different presentations demonstrated that the fields of metronomic chemotherapy and repurposing drugs in oncology, known as metronomics, constitute a branch of cancer therapy in permanent evolution, which have strong groups working in Latin

America, both in the preclinical and the clinical settings including large, adequately designed randomised studies. It was shown that metronomics offers treatments, which, whether they are combined or not with the standard therapeutic approaches, are not only effective but also minimally toxic, with the consequent improvement of the patient’s quality of life, and inexpensive, a feature very important in low resource clinical settings. The potential use of metronomic chemotherapy was proposed as a cost/effective treatment in low-/middle-income countries, for adjuvant therapy in selected tumours. The fundamental role of the governmental agencies and non-governmental alliances, as the Metronomic Global Health Initiative, in supporting this research with public interest was underlined.

Quality of life in patients with metastatic breast cancer treated with metronomic chemotherapy

AIM

The objective of the study was to detect changes in quality of life (QoL) in metastatic breast cancer patients treated with metronomic chemotherapy with daily low doses of cyclophosphamide and celecoxib.

MATERIAL & METHODS

Patients included in a Phase II trial, treated with metronomic cyclophosphamide and celecoxib were included in the QoL study. Assessment of QoL was carried out every 2 months by the Functional Assessment of Cancer Therapy Breast (FACT-B) questionnaire, Brief Pain Inventory and Eastern Cooperative Oncologic Group scale. Data were analyzed at three time points: baseline (BL); middle of treatment (MT); and end of treatment (ET).

RESULTS

A total of 20 patients were included. All patients were heavily pretreated. Treatment showed a good and safe therapeutic profile. With FACT-B questionnaire, no significant differences were observed during the response period (BL-MT). However, a significant increase was observed in the Emotional well-being and Additional concerns axes, when the last time point was included in the analysis (BL-MT-ET). A significant decrease in the proportion of patients with pain was found when comparing BL with ET (p = 0.046). The assessment with Eastern Cooperative Oncologic Group scale showed that 26.7% (4/15) of the patients improved their functional status and 40% (6/15) showed no changes, while 33.3% (5/10) worsened it.

CONCLUSION

Patients treated metronomically for several months did not worsen their QoL. A high proportion of patients showed improvement or no changes and there were less patients with pain at the end of the treatment.

Effective Management of Advanced Angiosarcoma by the Synergistic Combination of Propranolol and Vinblastine-based Metronomic Chemotherapy: A Bench to Bedside Study

Background

Angiosarcomas are rare malignant tumors of vascular origin that represent a genuine therapeutic challenge. Recently, the combination of metronomic chemotherapy and drug repositioning has been proposed as an attractive alternative for cancer patients living in developing countries.

Methods

In vitro experiments with transformed endothelial cells were used to identify synergistic interactions between anti-hypertensive drug propranolol and chemotherapeutics. This led to the design of a pilot treatment protocol combining oral propranolol and metronomic chemotherapy. Seven consecutive patients with advanced/metastatic/recurrent angiosarcoma were treated with this combination for up to 12 months, followed by propranolol-containing maintenance therapy.

Findings

Gene expression analysis showed expression of ADRB1 and ADRB2 adrenergic receptor genes in transformed endothelial cells and in angiosarcoma tumors. Propranolol strongly synergized with the microtubule-targeting agent vinblastine in vitro, but only displayed additivity or slight antagonism with paclitaxel and doxorubicin. A combination treatment using bi-daily propranolol (40 mg) and weekly metronomic vinblastine (6 mg/m²) and methotrexate (35 mg/m²) was designed and used in 7 patients with advanced angiosarcoma. Treatment was well tolerated and resulted in 100% response rate, including 1 complete response and 3 very good partial responses, based on RECIST criteria. Median progression-free and overall survival was 11 months (range 5–24) and 16 months (range 10–30), respectively.

Interpretation

Our results provide a strong rationale for the combination of β-blockers and vinblastine-based metronomic chemotherapy for the treatment of advanced angiosarcoma. Furthermore, our study highlights the potential of drug repositioning in combination with metronomic chemotherapy in low- and middle-income country setting.

Funding

This study was funded by institutional and philanthropic grants.

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A strong synergism was identified between propranolol and vinblastine in an in vitro model of angiosarcoma.

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Adrenergic receptor expression was detected in angiosarcoma tumors providing a molecular target for propranolol.

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Propranolol and vinblastine-based metronomic chemotherapy led to 100% response in 7 patients with inoperable angiosarcoma.

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This treatment resulted in prolonged survival of angiosarcoma patients and warrants further investigation in larger trials.

Drug repurposing in oncology--patient and health systems opportunities

In most countries, healthcare service budgets are not likely to support the current explosion in the cost of new oncology drugs. Repurposing the large arsenal of approved, non-anticancer drugs is an attractive strategy to offer more-effective options to patients with cancer, and has the substantial advantages of cheaper, faster and safer preclinical and clinical validation protocols. The potential benefits are so relevant that funding of academically and/or independently driven preclinical and clinical research programmes should be considered at both national and international levels. To date, successes in oncology drug repurposing have been limited, despite strong evidence supporting the use of many different drugs. A lack of financial incentives for drug developers and limited drug development experience within the non-profit sector are key reasons for this lack of success. We discuss these issues and offer solutions to finally seize this opportunity in the interest of patients and societies, globally.

Beta Adrenergic Signaling: A Targetable Regulator of Angiosarcoma and Hemangiosarcoma

Human angiosarcomas and canine hemangiosarcomas are highly aggressive cancers thought to arise from cells of vascular origin. The pathological features, morphological organization, and clinical behavior of canine hemangiosarcomas are virtually indistinct from those of human angiosarcomas. Overall survival with current standard-of-care approaches remains dismal for both humans and dogs, and each is likely to succumb to their disease within a short duration. While angiosarcomas in humans are extremely rare, limiting their study and treatment options, canine hemangiosarcomas occur frequently. Therefore, studies of these sarcomas in dogs can be used to advance treatment approaches for both patient groups. Emerging data suggest that angiosarcomas and hemangiosarcomas utilize beta adrenergic signaling to drive their progression by regulating the tumor cell niche and fine-tuning cellular responses within the tumor microenvironment. These discoveries indicate that inhibition of beta adrenergic signaling could serve as an Achilles heel for these tumors and emphasize the need to design therapeutic strategies that target tumor cell and stromal cell constituents. In this review, we summarize recent discoveries and present new hypotheses regarding the roles of beta adrenergic signaling in angiosarcomas and hemangiosarcomas. Because the use of beta adrenergic receptor antagonists is well established in human and veterinary medicine, beta blockade could provide an immediate adjunct therapy for treatment along with a tangible opportunity to improve upon the outcomes of both humans and dogs with these diseases.