The Angiosarcoma Project: enabling genomic and clinical discoveries in a rare cancer through patient-partnered research

Analysis of VEGFR-2 and PDGFR-β expression in canine splenic hemangiosarcoma to identify drug repositioning candidates

Splenic tumors are very common in dogs, and canine hemangiosarcoma (HSA) is one of the most important malignant splenic tumors. Surgery followed by chemotherapy (anthracycline-based protocols) is recommended for treating canine HSA; however, patients still do not achieve long-term survival. Therefore, this research aimed to assess vascular endothelial growth factor receptor-2 (VEGFR-2) and platelet-derived growth factor receptor-β (PDGFR-β) gene expression in formalin-fixed tissues, evaluate the quality of mRNA for quantitative polymerase chain reaction (qPCR) analysis and identify drug repositioning candidates based on VEGFR-2 and PDGFR-β. qPCR analysis identified the relative expression of heterogeneous VEGFR-2 and PDGFR-β, with samples showing no transcripts or very low expression and those with higher relative quantification for both genes. We then used immunohistochemistry to correlate the relative quantification of VEGFR-2 and PDGFR-β transcripts with respective higher protein expression to validate our results. In the next step, we evaluated drug repositioning candidates and identified small molecule inhibitors (i.e. sorafenib) and natural compounds (curcumin and resveratrol) with the ability to block VEGFR-2 and PDGFR-β genes. Overall, our results indicated that VEGFR-2 and PDGFR-β expression is highly variable among canine HSA samples and different drugs can block the expression of both genes. Therefore, a personalized approach could be useful for selecting anti-VEGFR-2 and PDGFR-β therapies and both genes are potential candidates for future oncological panels.

The challenge of running trials in advanced angiosarcoma: A systematic review of the literature from EORTC/STBSG to guide the development of angiosarcoma-specific trials

INTRODUCTION

While available systemic treatments have modest long term efficacy in advanced angiosarcoma, immunotherapy represents an interesting new therapeutic opportunity. To establish its benefit, it is required to conduct a clinical trial assessing its efficacy and toxicity compared to standard treatments.

MATERIAL AND METHODS

This is a literature review from PubMed search.

RESULTS

Several systemic treatments (chemotherapy and TKI) are currently used in advanced angiosarcoma with ORR ranging from 12.5 to 68 % and PFS from 2 to 7 months. However, few randomized trials, mainly phase II, has been conducted to compare these treatments. While most centers propose doxorubicin containing regimens or paclitaxel in 1st or 2nd line, a high heterogeneity of regimens administered in this setting is observed even across sarcoma specialized centers with no consensual standard treatment. Encouraging signals of immunotherapy activity have been reported in angiosarcoma from several retrospective and phase II studies assessing anti-PD1 either alone or in combination with anti CTLA4 or TKI. Although cutaneous and head and neck location seems to benefit more from immunotherapy, response may be observed in any angiosarcoma subtype. In sarcoma in general and AS in particular, no biomarker has been clearly established to predict the efficacy of immunotherapy: high tumor mutational burden and presence of tertiary lymphoid structures are under assessment.

DISCUSSION

Even essential, developing a randomized clinical trial in AS struggles with the heterogeneity of the disease, the lack of consensual standard regimen, the uncertainty on optimal immunotherapy administration and the absence of established predictive biomarkers.

CONCLUSION

International collaboration is essential to run randomized trial in advanced AS and asses the efficacy of immune therapy in this rare and heterogeneous disease.

Head and Neck Vascular Anomalies in Children

Craniomaxillofacial vascular anomalies encompass a diverse and complex set of pathologies that may have a profound impact on pediatric patients. They are subdivided into vascular tumors and vascular malformations depending on biological properties, clinical course, and distribution patterns. Given the complexity and potential for leading to significant functional morbidity and esthetic concerns, a multidisciplinary approach is generally necessary to optimize patient outcomes. This article reviews the etiology, clinical course, diagnosis, and current management practices related to vascular anomalies in the head and neck.

Molecular and immune pathobiology of human angiosarcoma

Angiosarcoma is a rare endothelial-derived malignancy that is extremely diverse in anatomy, aetiology, molecular and immune characteristics. While novel therapeutic approaches incorporating targeted agents and immunotherapy have yielded significant improvements in patient outcomes across several cancers, their impact on angiosarcoma remains modest. Contributed by its heterogeneous nature, there is currently a lack of novel drug targets in this disease entity and no reliable biomarkers that predict response to conventional treatment. This review aims to examine the molecular and immune landscape of angiosarcoma in association with its aetiology, anatomical sites, prognosis and therapeutic options. We summarise current efforts to characterise angiosarcoma subtypes based on molecular and immune profiling. Finally, we highlight promising technologies such as single-cell spatial "omics" that may further our understanding of angiosarcoma and propose strategies that can be similarly applied for the study of other rare cancers.

Sarcoma incidence worldwide: regional differences in histology and molecular subtypes

PURPOSE OF REVIEW

There are numerous sarcoma subtypes and vary widely in terms of epidemiology, clinical characteristics, genetic profiles, and pathophysiology. They also differ widely between ethnic groups. This review focuses on the different incidence rates of sarcomas in different regions and the potential explanations for these disparities.

RECENT FINDINGS

In an intercontinental study using national cancer registry databases from France and Taiwan, the French population had a higher risk of liposarcomas, leiomyosarcomas, and synovial sarcomas, whereas the Taiwanese population had a higher incidence of angiosarcomas and malignant peripheral nerve sheath tumors. The anatomical distribution of these sarcomas also varied between these two regions. In France, most angiosarcoma cases occurred in the extremities and trunk, whereas in Taiwan, angiosarcoma cases in the abdomen and pelvis were more common. Another international study showed that in addition to the common known TP53 and NF1 germline mutations, genes involved in centromere and telomere maintenance were also involved in sarcomagenesis. We reviewed factors related to genetics, environmental effects, chemical exposure, and radiation exposure that could explain the differences in sarcoma incidence among different geographical or ethnic regions.

SUMMARY

Our understanding of the potential cause of sarcomas with different subtypes is limited. Establishing a comprehensive global database for patients with sarcomas from all ethnic groups is essential to deepen our understanding of the potential risk factors and the pathophysiology of all sarcoma subtypes.

Angiosarcoma: clinical outcomes and prognostic factors, a single-center analysis

PURPOSE

This study sought to investigate oncological outcomes and prognostic factors for patients with angiosarcomas (AS).

METHODS

This single-center, retrospective cohort study, analyzed histopathologically confirmed AS cases. Primarily diagnosed, locally recurrent and metastatic AS were included. Overall survival (OS), local control (LC) and local progression-free survival (LPFS) were assessed by Kaplan-Meier estimator. Multivariable Cox regression analysis was performed to detect factors associated with OS and LPFS.

RESULTS

In total, 118 patients with a median follow-up of 6.6 months were included. The majority presented with localized disease (62.7%), followed by metastatic (31.4%) and locally recurrent (5.9%) disease. Seventy-four patients (62.7%) received surgery, of which 29 (39.2%) were treated with surgery only, 38 (51.4%) with surgery and perioperative radiotherapy or chemotherapy, and 7 (9.4%) with surgery, perioperative radiotherapy and chemotherapy. Multivariable Cox regression of OS showed a significant association with age per year (hazard ratio (HR): 1.03, p = 0.044) and metastatic disease at presentation (hazard ratio: 3.24, p = 0.015). For LPFS, age per year (HR: 1.04, p = 0.008), locally recurrent disease at presentation (HR: 5.32, p = 0.013), and metastatic disease at presentation (HR: 4.06, p = 0.009) had significant associations. Tumor size, epithelioid components, margin status, and perioperative RT and/or CTX were not significantly associated with OS or LPFS.

CONCLUSION

Older age and metastatic disease at initial presentation status were negatively associated with OS and LPFS. Innovative and collaborative effort is warranted to overcome the epidemiologic challenges of AS by collecting multi-institutional datasets, characterizing AS molecularly and identifying new perioperative therapies to improve patient outcomes.

Hemangiosarcoma Cells Promote Conserved Host-derived Hematopoietic Expansion

Hemangiosarcoma and angiosarcoma are soft-tissue sarcomas of blood vessel-forming cells in dogs and humans, respectively. These vasoformative sarcomas are aggressive and highly metastatic, with disorganized, irregular blood-filled vascular spaces. Our objective was to define molecular programs which support the niche that enables progression of canine hemangiosarcoma and human angiosarcoma. Dog-in-mouse hemangiosarcoma xenografts recapitulated the vasoformative and highly angiogenic morphology and molecular characteristics of primary tumors. Blood vessels in the tumors were complex and disorganized, and they were lined by both donor and host cells. In a series of xenografts, we observed that the transplanted hemangiosarcoma cells created exuberant myeloid hyperplasia and gave rise to lymphoproliferative tumors of mouse origin. Our functional analyses indicate that hemangiosarcoma cells generate a microenvironment that supports expansion and differentiation of hematopoietic progenitor populations. Furthermore, gene expression profiling data revealed hemangiosarcoma cells expressed a repertoire of hematopoietic cytokines capable of regulating the surrounding stromal cells. We conclude that canine hemangiosarcomas, and possibly human angiosarcomas, maintain molecular properties that provide hematopoietic support and facilitate stromal reactions, suggesting their potential involvement in promoting the growth of hematopoietic tumors.

SIGNIFICANCE

We demonstrate that hemangiosarcomas regulate molecular programs supporting hematopoietic expansion and differentiation, providing insights into their potential roles in creating a permissive stromal-immune environment for tumor progression.

Improving Diagnosis and Care for Patients With Sarcoma: Do Real-World General Practitioners Data and Prospective Data Collections Have a Place Next to Clinical Trials?

There has been growing interest in the use of real-world data (RWD) to address clinically and policy-relevant (research) questions that cannot be answered with data from randomized controlled trials (RCTs) alone. This is, for example, the case in rare malignancies such as sarcomas as limited patient numbers pose challenges in conducting RCTs within feasible timeliness, a manageable number of collaborators, and statistical power. This narrative review explores the potential of RWD to generate real-world evidence (RWE) in sarcoma research, elucidating its application across different phases of the patient journey, from prediagnosis to the follow-up/survivorship phase. For instance, examining electronic health records (EHRs) from general practitioners (GPs) enables the exploration of consultation frequency and presenting symptoms in primary care before a sarcoma diagnosis. In addition, alternative study designs that integrate RWD with well-designed observational RCTs may offer relevant information on the effectiveness of clinical treatments. As, especially in cases of ultrarare sarcomas, it can be an extreme challenge to perform well-powered randomized prospective studies. Therefore, it is crucial to support the adaptation of novel study designs. Regarding the follow-up/survivorship phase, examining EHR from primary and secondary care can provide valuable insights into identifying the short- and long-term effects of treatment over an extended follow-up period. The utilization of RWD also comes with several challenges, including issues related to data quality and privacy, as described in this study. Notwithstanding these challenges, this study underscores the potential of RWD to bridge, at least partially, gaps between evidence and practice and holds promise in contributing to the improvement of sarcoma care.

Promise and Perils of Precision Oncology for Patients With Pediatric and Young Adult Sarcomas

The completion of multiple national pediatric precision oncology platform trials and the incorporation of standardized molecular profiling into the diagnostic care of pediatric and young adult patients with sarcomas have proven the feasibility and potential of the approach. In this work, we explore the current state of the art of precision oncology for pediatric and young adults with sarcoma. We highlight important lessons learned and the challenges that should be addressed in the next generation of trials. The chapter outlines current efforts to improve standardization of molecular assays, harmonization of data collection, and novel molecular tools such as cell-free DNA analyses. Finally, we discuss the impacts and psychosocial outcomes experienced by patients and communication strategies for providers.

Immunotherapy in Sarcoma: Current Data and Promising Strategies

Traditionally sarcomas have been considered immunologically quiet tumours, with low tumour mutational burden (TMB) and an immunosuppressive tumour microenvironment (TME), consisting of decreased T-cell infiltration and elevated levels of H1F1α, macrophages and neutrophils.1,2 However, research has shown that a subset of sarcomas are immunologically 'hot' with either high TMB, PDL-1 expression, CD8+ T cells or presence of tertiary lymphoid structures (TLS) demonstrating sensitivity to immunotherapy.3,4 Here, we review the current evidence for immunotherapy use in bone sarcomas (BS) and soft tissue sarcomas (STS), with immune checkpoint inhibitors (ICI) and adoptive cellular therapies including engineered T-cell therapies, chimeric antigen receptor (CAR) T-cell therapies, tumour infiltrating lymphocytes (TILs) and cancer vaccines and biomarkers of response.

Generation of sarconoids from angiosarcoma patients as a systematic-based rational approach to treatment

Angiosarcoma is a rare subtype of malignant neoplasm originating from vascular or lymphatic endothelial cells; its low incidence has posed significant challenges for comprehensive investigations into its pathogenic mechanisms and the development of innovative treatment modalities through in vitro and in vivo models. Recent endeavors spearheaded by patient-partnered research initiatives have aimed to elucidate the intricacies of angiosarcomas by leveraging biological omics approaches, with the overarching objective of enhancing prognostic indicators and therapeutic options for this uncommon pathology. To bridge the gap between preclinical research and translational applications, we engineered angiosarcoma-derived organoids from surgically resected primary tumors, hereafter referred to as "sarconoids," as a proof-of-concept model. A novel protocol for the establishment of these sarconoids has been developed and validated. To ensure that the sarconoids faithfully recapitulate the heterogeneity and complexities of the patients' original tumors, including transcriptomic signatures, cell-type specificity, and morphological traits, exhaustive histological and transcriptomic analyses were conducted. Subsequently, we expanded the scope of our study to include an evaluation of a sarconoid-based drug screening platform; for this purpose, a drug library (AOD IX), supplied by the National Cancer Institute's Developmental Therapeutics Program, was screened using 96-well plates. Our findings suggest that sarconoids can be reliably generated from angiosarcoma patient-derived tissues and can serve as accurate models for evaluating therapeutic responses, thereby holding far-reaching implications for translational research and clinical applications aimed at advancing our understanding and treatment of angiosarcoma.

UK guidelines for the management of soft tissue sarcomas

Soft tissue sarcomas (STS) are rare tumours arising in mesenchymal tissues and can occur almost anywhere in the body. Their rarity, and the heterogeneity of subtype and location, means that developing evidence-based guidelines is complicated by the limitations of the data available. This makes it more important that STS are managed by expert multidisciplinary teams, to ensure consistent and optimal treatment, recruitment to clinical trials, and the ongoing accumulation of further data and knowledge. The development of appropriate guidance, by an experienced panel referring to the evidence available, is therefore a useful foundation on which to build progress in the field. These guidelines are an update of the previous versions published in 2010 and 2016 [1, 2]. The original guidelines were drawn up by a panel of UK sarcoma specialists convened under the auspices of the British Sarcoma Group (BSG) and were intended to provide a framework for the multidisciplinary care of patients with soft tissue sarcomas. This iteration of the guidance, as well as updating the general multidisciplinary management of soft tissue sarcoma, includes specific sections relating to the management of sarcomas at defined anatomical sites: gynaecological sarcomas, retroperitoneal sarcomas, breast sarcomas, and skin sarcomas. These are generally managed collaboratively by site specific multidisciplinary teams linked to the regional sarcoma specialist team, as stipulated in the recently published sarcoma service specification [3]. In the UK, any patient with a suspected soft tissue sarcoma should be referred to a specialist regional soft tissues sarcoma service, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging and a tissue biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon, combined with pre- or post-operative radiotherapy for tumours at higher risk for local recurrence. Systemic anti-cancer therapy (SACT) may be utilised in cases where the histological subtype is considered more sensitive to systemic treatment. Regular follow-up is recommended to assess local control, development of metastatic disease, and any late effects of treatment.

Propranolol monotherapy in angiosarcoma - A window-of-opportunity study (PropAngio)

BACKGROUND

Angiosarcoma is a rare and aggressive cancer of the endothelial cells. Propranolol, a non-selective β-blocker, was able to initiate apoptosis in angiosarcoma cell lines and its anti-tumor activity has been described in several case reports. The aim of this trial was to prospectively evaluate the anti-tumor activity of propranolol monotherapy in patients with angiosarcoma before proceeding to standard of care treatment.

METHODS

Propranolol was dosed 80 mg to 240 mg/day for 3 to 6 weeks according to a dose titration schedule. The primary endpoint was clinical response (response according to RECIST 1.1 or stable disease with improvement of cutaneous lesions) in at least three patients. Exploratory objectives included histologic response (>30% decrease in Ki-67), FDG PET response, and β-receptor expression levels.

RESULTS

Fourteen patients were enrolled. The median duration of treatment was 26 days (range 21-42 days). The median highest propranolol dose was 160 mg/day (range 80 - 240 mg). Two patients showed clinical response (14%, 95% CI 3-100%). One of these patients showed a partial metabolic response on PET-CT. None of the tumors showed histologic response. The most common adverse event was grade 1/2 bradycardia (86%). There were no grade ≥ 3 adverse events. ADRB2 was overexpressed in 16 out of 18 tumors, in both responders and non-responders. None of the tumors showed ADRB1 overexpression.

CONCLUSIONS

This window-of-opportunity trial did not show clinical efficacy of propranolol monotherapy. However, two out of 14 patients did show clinical benefit. ADRB1/2 expression did not correlate with clinical response.

Tumor Immune Microenvironment and Its Clinicopathological and Prognostic Associations in Canine Splenic Hemangiosarcoma

Tumor cells can induce important cellular and molecular modifications in the tissue or host where they grow. The idea that the host and tumor interact with each other has led to the concept of a tumor microenvironment, composed of immune cells, stromal cells, blood vessels, and extracellular matrix, representing a unique environment participating and, in some cases, promoting cancer progression. The study of the tumor immune microenvironment, particularly focusing on the role of tumor-infiltrating lymphocytes (TILs), is highly relevant in oncology due to the prognostic and therapeutic significance of TILs in various tumors and their identification as targets for therapeutic intervention. Canine splenic hemangiosarcoma (HSA) is a common tumor; however, its immune microenvironment remains poorly understood. This retrospective study aimed to characterize the histological and immunohistochemical features of 56 cases of canine splenic HSA, focusing particularly on tumor-infiltrating lymphocytes (TILs). We assessed the correlations between the lymphocytic response, the macroscopic and histological characteristics of the tumor, and the survival data. Our study demonstrated that FoxP3 distribution was associated with tumor-related death and survival, while the CD20 count was associated with metastasis. This study provides an in-depth characterization of the tumor immune microenvironment in canine splenic HSA and describes potential prognostic factors.

Primary splenic angiosarcoma: a case series of a rare oncological entity and diagnostic challenge

BACKGROUND AND PURPOSE

Primary angiosarcoma of the spleen (PAS), an exceptionally rare and aggressive neoplasm with high metastatic risk (70%-85%), is frequently diagnosed in an advanced or metastatic stage. It presents diagnostic challenges due to its nonspecific symptomatology and resemblance to benign vascular lesions in various imaging modalities.

PATIENTS AND METHODS

This case series aims to clarify the diagnostic difficulties by comparing imaging characteristics (CT-scan, MRI, and [18F]FDG-PET/CT) as well as pathological findings of three PAS cases diagnosed in different stages of the diseases (localized, metastatic, and metastatic with organ failure). Furthermore, a brief review on diagnostic and therapeutic features is included.

RESULTS AND INTERPRETATION

We suggest [18F]FDG-PET/CT as a differentiating tool between benign and malignant splenic lesions and propose a flowchart of a diagnostic algorithm for PAS. For treatment, we advocate for early splenectomy and when systemic therapy is warranted, paclitaxel emerges as a viable first-line option. While it is crucial to acknowledge that further trial data is required to evaluate the efficacy of emerging treatment regimens, designing and conducting trials for PAS is challenging given its scarcity and aggressive behavior. Therefore case reporting remains important.

Chemo-Senolytic Therapeutic Potential against Angiosarcoma

Angiosarcoma is an aggressive soft-tissue sarcoma with a poor prognosis. Chemotherapy for this cancer typically employs paclitaxel, a taxane (genotoxic drug), although it has a limited effect owing to chemoresistance to prolonged treatment. In this study, we examine an alternative angiosarcoma treatment approach that combines chemotherapeutic and senolytic agents. We find that the chemotherapeutic drugs cisplatin and paclitaxel efficiently induce senescence in angiosarcoma cells. Subsequent treatment with the senolytic agent ABT-263 eliminates senescent cells by activating the apoptotic pathway. In addition, expression analysis indicates that senescence-associated secretory phenotype genes are activated in senescent angiosarcoma cells and that ABT-263 treatment downregulates IFN-I pathway genes in senescent cells. Moreover, we show that cisplatin treatment alone requires high doses to remove angiosarcoma cells. In contrast, lower doses of cisplatin are sufficient to induce senescence, followed by the elimination of senescent cells by the senolytic treatment. This study sheds light on a potential therapeutic strategy against angiosarcoma by combining a relatively low dose of cisplatin with the ABT-263 senolytic agent, which can help ease the deleterious side effects of chemotherapy.

Incidence and Presenting Characteristics of Angiosarcoma in the US, 2001-2020

Importance

Angiosarcoma is an aggressive vascular malignant neoplasm presenting either as a primary or secondary cancer, often arising after radiotherapy or in the context of preexisting lymphedema. Comprehensive data describing its incidence and presentation patterns are needed.

Objective

To describe the incidence, presenting characteristics, and change over time of angiosarcoma in the US.

Design, Setting, and Participants

This retrospective cross-sectional study used data from the US Cancer Statistics (USCS) National Program of Cancer Registries-Surveillance, Epidemiology, and End Results Combined Database, which captures more than 99% of newly diagnosed cancers in the US. The study included all 19 289 patients in the US with a new diagnosis of angiosarcoma between 2001 and 2020 captured in the USCS database. Statistical analysis was performed from June to September 2023.

Main Outcomes and Measures

Incidence of angiosarcoma, demographics of patients with angiosarcoma, and extent of disease at presentation.

Results

The study included 19 289 patients (median age, 71 years [IQR, 59-80 years]; 10 506 women [54.5%]) with a new diagnosis of angiosarcoma. The US incidence of angiosarcoma doubled between 2001 (657 cases) and 2019 (1312 cases), reflecting both an increase in the adjusted incidence rate of 1.6% per year (P = .001), to 3.3 cases per 1 000 000 person-years (95% CI, 3.1-3.5 cases per 1 000 000 person-years), and an increase in the population at risk. In 2020, the reported incidence rate (3.0 cases per 1 000 000 person-years) and cases of angiosarcoma (n = 1159) were modestly lower than in 2019. Overall, 72.3% of cases of angiosarcoma (n = 13 955) were cutaneous, subcutaneous, or breast angiosarcomas; 24.4% were visceral (n = 4701); and 3.3% were located in unknown or rare primary sites (n = 633). Secondary breast and chest wall angiosarcomas among women represented the largest contribution to increasing incidence. Among breast angiosarcomas, 99.2% (2684 of 2705) were in women and 71.9% (1944 of 2705) were secondary. A total of 80.4% of chest wall or thorax cases among women (1861 of 2316) were secondary vs 26.5% among men (112 of 422), and 63.9% of upper extremity cases among women (205 of 321) were secondary vs 26.8% (56 of 209) among men (P = .001). Rates of secondary angiosarcoma in the abdomen and lower extremities were similar between men and women. The incidence rate of visceral angiosarcoma was also found to be increasing (1.5% per year; P = .001).

Conclusions and Relevance

This cross-sectional study describes angiosarcoma presentation patterns and incidence rates in the US over a 20-year period and shows that the number of cases in men and women increased, with the greatest increase among women with secondary angiosarcoma of the chest, breast, and upper extremity. These data increase awareness of a rare but highly morbid disease and highlight the need for improved early detection of angiosarcoma among patients at high risk, such as women with a history of breast cancer.

Sarcoma in patients with Lynch syndrome and response to immunotherapy

BACKGROUND

Lynch syndrome (LS) is an autosomal dominant genetic predisposition to multiple malignancies and is characterized by deficient DNA mismatch repair. Increased incidence of sarcomas is not formally ascribed to LS; however, increasing evidence suggests a preponderance of these malignancies in affected families. Sarcomas typically possess a low tumor mutational burden and incite a poor immune infiltrate, thereby rendering them poorly responsive to immunotherapy.

METHODS

We searched the University of California, Los Angeles (UCLA) sarcoma program database for patients with a diagnosis of sarcoma and LS from 2016 to 2023. Three such patients were identified and all three were treated with PD1 blockade.

RESULTS

We present three cases of LS-associated sarcomas (two soft tissue sarcoma and one osteosarcoma) with increased tumor mutational burdens. These patients were each treated with an anti-PD1 antibody and experienced a response far superior to that reported for non-LS-associated sarcomas.

CONCLUSIONS

Increased mutational burden and immune infiltrate are observed for sarcomas associated with LS. Although unselected patients with sarcoma have demonstrated poor response rates to immunotherapy, our findings suggest that patients with Lynch-associated sarcomas are more likely to respond to treatment with anti-PD1. These patients should be given consideration for immunotherapy.

Radiation-induced angiosarcoma of the breast: retrospective analysis at a regional treatment centre

BACKGROUND

Radiation-induced angiosarcoma (RIA) is an uncommon but morbid complication after radiotherapy for breast cancer.

METHODS

Retrospective analysis of breast RIA patients at Cambridge University Hospital (CUH), a regional treatment centre in the East of England.

RESULTS

22 patients were identified between 2010 and 2022. Median age of diagnosis was 65 years (range 41-78). Median time from breast radiotherapy to RIA diagnosis was 6.5 years (range 2.4-16.0)-this interval has decreased over the last 24 years (r2 = 0.6601). 9% had metastasis at presentation. All patients underwent surgery (55% at CUH, 45% at local hospitals). 27% received peri-operative pegylated liposomal doxorubicin in the first-line setting. 62% relapsed following their primary curative-intent treatments after a median of 28 months. Metastases occurred in 36%, the commonest sites being lung (100%) and lymph node (50%). 2-year and 5-year overall survival (OS) rates for all patients were 73% and 60%, respectively. No correlation between progression-free survival (PFS) and OS was found with tumour size, margin, peri-operative chemotherapy, and whether surgery was performed at CUH. Patients with multifocal disease on their breasts had shorter PFS following surgery compared to single-lesion disease (median 10 vs 65 months; HR = 4.359 [95% CI 1.342-14.16]; P = 0.0143). Patients aged > 72 years had a median OS of 45 months vs 102 months for those ≤ 72 years (HR = 7.129 [95% CI 1.646-30.88]; P = 0.0086).

CONCLUSION

RIA has high rates of recurrence and mortality and appears to be occurring sooner after breast radiotherapy. Further studies on its pathogenesis and effective treatment are warranted.

Tumor-Infiltrating Mast Cells in Angiosarcoma Correlate With Immuno-Oncology Pathways and Adverse Clinical Outcomes

Recent studies have described several molecular subtypes and deregulation of immuno-oncologic signaling pathways in angiosarcoma. Interestingly, mast cells were enriched in subsets of angiosarcoma, although their significance remains unknown. In this study, we aim to verify this observation using immunohistochemistry (H scores) and NanoString transcriptomic profiling and explore the association between mast cells with clinical and biological features. In the study cohort (N = 60), H scores showed a significant moderate correlation with NanoString mast cell scores (r = 0.525; P < .001). Both H score and NanoString mast cell scores showed a significant positive correlation (P < .05) with head and neck location, nonepithelioid morphology, and lower tumor grade. Mast cell enrichment significantly correlated with higher NanoString regulatory T-cell scores (H score, r = 0.32; P = .01; NanoString mast cell score, r = 0.27; P = .04). NanoString mast cell scores positively correlated with signaling pathways relating to antigen presentation (r = 0.264; P = .0414) and negatively correlated with apoptosis (r = -0.366; P = .0040), DNA damage repair (r = -0.348; P = .0064), and cell proliferation (r = -0.542; P < .001). Interestingly, in the metastatic setting, patients with mast cell-enriched angiosarcoma showed poorer progression-free survival (median, 0.2 vs 0.4 years; hazard ratio = 3.05; P = .0489) along with a trend toward worse overall survival (median, 0.2 vs 0.6 years; hazard ratio, 2.86; P = .0574) compared with patients with mast cell-poor angiosarcoma. In conclusion, we demonstrated the presence of mast cells in human angiosarcoma and provided initial evidence of their potential clinical and biological significance. Future research will be required to elucidate their specific roles and mechanisms, which may uncover novel avenues for therapeutic intervention.

Angiosarcoma of the breast: A review

Breast angiosarcoma is a rare and highly aggressive malignancy with a poor prognosis. It can occur spontaneously or be associated with factors such as radiation therapy or chronic lymphedema. The etiology and pathogenesis of this disease are still unclear, the clinical symptoms and imaging findings lack specificity, and the pathological morphology is diverse, which is easy to be confused with other diseases. There is no clear guideline for surgical treatment. Although the optimal surgical approach remains unclear, the ultimate goal is surgical excision with optimal margins, which remains the primary method of treatment. In clinical practice, the choice of the surgical approach should be made by considering the tumor size, pathological type, and patient preferences. In clinical practice, the selection of surgical methods should be carried out with comprehensive consideration of tumor size, pathological types and patients' wishes. There is no clear consensus on whether radiotherapy and chemotherapy should be carried out after surgery, and its optimal program and efficacy are uncertain. This article reviews the etiology, clinical manifestations, pathological features, imaging findings, treatment, prognosis and other aspects of breast angiosarcoma, so as to strengthen clinicians' overall understanding of this disease and avoid missed diagnosis and misdiagnosis.

Anastomosing haemangioma of the mediastinum: Clinicopathological series with radiological and genetic characterisation

AIMS

Anastomosing haemangiomas are benign tumours with anastomosing vascular channels that may mimic angiosarcoma. While anastomosing haemangiomas have been described in diverse locations, particularly the abdominal/paraspinal region, data on anastomosing haemangiomas in the mediastinum remain limited. We report the clinicopathological, radiological and molecular characteristics of the largest single-institutional series of mediastinal anastomosing haemangiomas.

METHODS AND RESULTS

In our pathology archives in 2011-23, we reviewed all vascular lesions involving the mediastinum and identified seven anastomosing haemangiomas. Clinical information was abstracted from medical charts; available radiological imaging was reviewed. Targeted DNA-based next-generation sequencing (447 genes, including GNAQ and GNA11) was performed on five cases. The seven patients included five women and two men, with an age range of 55-77 (median = 72) years. Of the six tumours with available radiology, two each were in the prevascular, visceral and paravertebral mediastinum, with lobulated peripheral enhancement in all tumours examined with contrast enhancement. Six patients underwent tumour resection; one patient received proton radiotherapy. Microscopically, each tumour was solitary and characterised by anastomosing capillary-sized vessels lined by hobnail endothelial cells. Fibrin microthrombi, hyaline globules and extramedullary haematopoiesis were common. In the five tumours analysed by next-generation sequencing, GNAQ p.Q209P was identified in one tumour; no additional reportable alterations were identified in the remaining cases. No recurrence was noted in the four patients with available follow-up of 3-58 (median = 9.5) months after resection.

CONCLUSION

While mediastinal anastomosing haemangiomas can microscopically mimic angiosarcoma, awareness of this entity and radiological correlation may help to circumvent this diagnostic pitfall.

Genomic Landscape Comparison of Cardiac versus Extra-Cardiac Angiosarcomas

Angiosarcomas (ASs) are rare malignant vascular entities that can affect several regions in our body, including the heart. Cardiac ASs comprise 25-40% of cardiac sarcomas and can cause death within months of diagnosis. Thus, our aim was to identify potential differences and/or similarities between cardiac and extra-cardiac ASs to enhance targeted therapies and, consequently, patients' prognosis. Whole-transcriptome analysis of three cardiac and eleven extra-cardiac non-cutaneous samples was performed to investigate differential gene expression and mutational events between the two groups. The gene signature of cardiac and extra-cardiac non-cutaneous ASs was also compared to that of cutaneous angiosarcomas (n = 9). H/N/K-RAS and TP53 alterations were more recurrent in extra-cardiac ASs, while POTE-gene family overexpression was peculiar to cardiac ASs. Additionally, in vitro functional analyses showed that POTEH upregulation conferred a growth advantage to recipient cells, partly supporting the cardiac AS aggressive phenotype and patients' scarce survival rate. These features should be considered when investigating alternative treatments.

Hemangiosarcoma in dogs as a potential non-rodent animal model for drug discovery research of angiosarcoma in humans

Since the domestication of dogs 10,000 years ago, they have shared their living environment with humans and have co-evolved. The breeding process that dogs have undergone in only a few centuries has led to a significant accumulation of specific genetic alterations that could induce particular diseases in certain breeds. These canine diseases are similar to what is found in humans with several differences; therefore, comparing such diseases occurring in humans and dogs can help discover novel disease mechanisms, pathways, and causal genetic factors. Human angiosarcoma (AS) and canine hemangiosarcoma (HSA), which are sarcomas originating from endothelium, are examples of diseases shared between humans and dogs. They exhibit similar characteristics and clinical behaviors, although with some critical differences resulting from evolution. In this review, we will describe the similarities and differences in terms of clinical and molecular characteristics between human AS and canine HSA, and discuss how these similarities and differences can be applied to advance the treatment of these diseases.

Longitudinal Natural History Study of Children and Adults with Rare Solid Tumors: Initial Results for First 200 Participants

Understanding of tumor biology and identification of effective therapies is lacking for many rare tumors. My Pediatric and Adult Rare Tumor (MyPART) network was established to engage patients, advocates, and researchers and conduct a comprehensive longitudinal Natural History Study of Rare Solid Tumors. Through remote or in-person enrollment at the NIH Clinical Center, participants with rare solid tumors ≥4 weeks old complete standardized medical and family history forms, patient reported outcomes, and provide tumor, blood and/or saliva samples. Medical records are extracted for clinical status and treatment history, and tumors undergo genomic analysis. A total of 200 participants (65% female, 35% male, median age at diagnosis 43 years, range = 2-77) enrolled from 46 U.S. states and nine other countries (46% remote, 55% in-person). Frequent diagnoses were neuroendocrine neoplasms (NEN), adrenocortical carcinomas (ACC), medullary thyroid carcinomas (MTC), succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumors (sdGIST), and chordomas. At enrollment, median years since diagnosis was 3.5 (range = 0-36.6), 63% participants had metastatic disease and 20% had no evidence of disease. Pathogenic germline and tumor mutations included SDHA/B/C (sdGIST), RET (MTC), TP53 and CTNNB1 (ACC), MEN1 (NEN), and SMARCB1 (poorly-differentiated chordoma). Clinically significant anxiety was observed in 20%-35% of adults. Enrollment of participants and comprehensive data collection were feasible. Remote enrollment was critical during the COVID-19 pandemic. Over 30 patients were enrolled with ACC, NEN, and sdGIST, allowing for clinical/genomic analyses across tumors. Longitudinal follow-up and expansion of cohorts are ongoing to advance understanding of disease course and establish external controls for interventional trials.

SIGNIFICANCE

This study demonstrates that comprehensive, tumor-agnostic data and biospecimen collection is feasible to characterize different rare tumors, and speed progress in research. The findings will be foundational to developing external controls groups for single-arm interventional trials, where randomized control trials cannot be conducted because of small patient populations.

Paranasal sinus angiosarcoma with facial paralysis as a novel manifestation: a case report and literature review

BACKGROUND

Paranasal sinus angiosarcoma is an uncommon malignancy, with only a few reported cases worldwide. Although it exhibits multiple symptoms, facial paralysis has not been previously documented as a noticeable presentation.

CASE PRESENTATION

In this case, we report a 40-year-old male who presented with facial numbness and pain for one month, weakness of his facial muscles for 15 days, and recurrent right epistaxis for 1 year. He had a history of nasal inflammatory polyps with chronic sinusitis. Computed tomography and magnetic resonance imaging showed space-occupying lesions in the right nasal cavity and maxillary sinus, with bone destruction occurring in the sinus wall and turbinate. This patient then underwent endoscopic surgery. According to the histopathological and immunohistochemical results, he was eventually diagnosed with paranasal sinus angiosarcoma in April 2021. To date, this patient has not initiated any radiotherapy or chemotherapy and has survived with lymphatic metastasis for at least 3 years.

CONCLUSIONS

This manuscript suggests that paranasal sinus angiosarcoma can present with facial paralysis. Moreover, pathological and immunohistochemical tests are still vital for diagnosing paranasal sinus angiosarcoma and differential diagnosis. Additionally, regular follow-up is crucial for patients with paranasal sinus angiosarcoma, enabling monitoring of recurrence, metastasis, and recovery while contributing valuable clinical data to understanding this rare disease and associated research endeavours.

Secondary Breast Angiosarcoma After a Primary Diagnosis of Breast Cancer: A Retrospective Analysis of the Surveillance, Epidemiology, and End Results (SEER) Database

OBJECTIVES

Angiosarcoma is a rare complication of breast-conserving therapy. This study evaluated the change in incidence between 1992 and 2016 of secondary breast angiosarcoma (SBA) in patients with a history of breast cancer and the impact of management strategies for the original breast carcinoma on angiosarcoma treatment.

METHODS

Breast cancer and angiosarcoma cases were abstracted from the Surveillance, Epidemiology, and End Result (SEER) database. SBAs were defined as angiosarcomas located in the breast occurring after a prior breast cancer diagnosis. Primary breast angiosarcomas (PBAs) were defined as an angiosarcoma diagnosis listed as "one primary only." Incidence rates were estimated using a proportion of the US total population. Survival was analyzed by the Kaplan-Meier method, and Cox proportional hazard models were used to assess the association of clinicopathologic characteristics on overall survival.

RESULTS

Between 1992 and 2016, 193 cases of SBA were reported in the SEER dataset in patients with a prior history of breast cancer. The incidence of breast angiosarcoma in patients with a prior diagnosis of breast cancer increased 3-fold from about 10 cases per 100,000 person-years to about 30 cases per 100,000 person-years over this same period ( P =0.0037). For treatment of SBA (n=193), almost all (95%) had surgery. Nine percent received radiation (compared with 35% of patients with PBA, P <0.001) and 23% received chemotherapy (vs. 45% for PBA, P =0.11).

CONCLUSIONS

We demonstrate an increasing incidence of SBA over the study period. These data can help inform shared decision-making for optimal management of locoregional breast cancer and raise awareness of secondary angiosarcoma.

Identification of genomic alterations with clinical impact in canine splenic hemangiosarcoma

Canine hemangiosarcoma (HSA) is an aggressive cancer of endothelial cells with short survival times. Understanding the genomic landscape of HSA may aid in developing therapeutic strategies for dogs and may also inform therapies for the rare and aggressive human cancer angiosarcoma. The objectives of this study were to build a framework for leveraging real-world genomic and clinical data that could provide the foundation for precision medicine in veterinary oncology, and to determine the relationships between genomic and clinical features in canine splenic HSA. One hundred and nine dogs with primary splenic HSA treated by splenectomy that had tumour sequencing via the FidoCure® Precision Medicine Platform targeted sequencing panel were enrolled. Patient signalment, weight, metastasis at diagnosis and overall survival time were retrospectively evaluated. The incidence of genomic alterations in individual genes and their relationship to patient variables including outcome were assessed. Somatic mutations in TP53 (n = 44), NRAS (n = 20) and PIK3CA (n = 19) were most common. Survival was associated with presence of metastases at diagnosis and germline variants in SETD2 and NOTCH1. Age at diagnosis was associated with somatic NRAS mutations and breed. TP53 and PIK3CA somatic mutations were found in larger dogs, while germline SETD2 variants were found in smaller dogs. We identified both somatic mutations and germline variants associated with clinical variables including age, breed and overall survival. These genetic changes may be useful prognostic factors and provide insight into the genomic landscape of hemangiosarcoma.

Genomic Profiling and Clinical Outcomes of Targeted Therapies in Adult Patients with Soft Tissue Sarcomas

Genomic profiling has improved our understanding of the pathogenesis of different cancers and led to the development of several targeted therapies, especially in epithelial tumors. In this review, we focus on the clinical utility of next-generation sequencing (NGS) to inform therapeutics in soft tissue sarcoma (STS). The role of NGS is still controversial in patients with sarcoma, given the low mutational burden and the lack of recurrent targetable alterations in most of the sarcoma histotypes. The clinical impact of genomic profiling in STS has not been investigated prospectively. A limited number of retrospective, mainly single-institution, studies have addressed this issue using various NGS technologies and platforms and a variety of criteria to define a genomic alteration as actionable. Despite the detailed reports on the different gene mutations, fusions, or amplifications that were detected, data on the use and efficacy of targeted treatment are very scarce at present. With the exception of gastrointestinal stromal tumors (GISTs), these targeted therapies are administered either through off-label prescription of an approved drug or enrollment in a matched clinical trial. Based mainly on anecdotal reports, the outcome of targeted therapies in the different STS histotypes is discussed. Prospective studies are warranted to assess whether genomic profiling improves the management of STS patients.

Immune-related Adverse Events after Immune Checkpoint Blockade-based Therapy Are Associated with Improved Survival in Advanced Sarcomas

The association between immune-related AEs (irAE) and outcome in patients with sarcoma is not known. We retrospectively reviewed a cohort of patients with advanced sarcoma treated with immune checkpoint blockade (ICB)-based therapy. Association of irAEs with survival was assessed using a Cox regression model that incorporated irAE occurrence as a time-dependent covariate. Tumor samples with available RNA sequencing data were stratified by presence of an irAE to identify patterns of differential gene expression. A total of 131 patients were included. Forty-two (32%) had at least one irAE of any grade and 16 (12%) had at least one grade ≥ 3 irAE. The most common irAEs were hypothyroidism (8.3%), arthralgias (5.3%), pneumonitis (4.6%), allergic reaction (3.8%), and elevated transaminases (3.8%). Median progression-free survival (PFS) and overall survival (OS) from the time of study entry were 11.4 [95% confidence interval (CI), 10.7-15.0) and 74.6 weeks (CI, 44.9-89.7), respectively. On Cox analysis adjusting for clinical covariates that were significant in the univariate setting, the HR for an irAE (HR, 0.662; CI, 0.421-1.041) approached, but did not reach statistical significance for PFS (P = 0.074). Patients had a significantly lower HR for OS (HR, 0.443; CI, 0.246-0.798; P = 0.007) compared with those without or before an irAE. Gene expression profiling on baseline tumor samples found that patients who had an irAE had higher numbers of tumor-infiltrating dendritic cells, CD8+ T cells, and regulatory T cells as well as upregulation of immune and inflammatory pathways.

SIGNIFICANCE

irAE after ICB therapy was associated with an improved OS; it also approached statistical significance for improved PFS. Patients who had an irAE were more likely to have an inflamed tumor microenvironment at baseline.

Current understanding of angiosarcoma: disease biology and evolving treatment

Angiosarcoma is a very rare soft tissue sarcoma that originates from endothelial cells and typically has a poor prognosis. It is most commonly found in elderly white men and can occur anywhere in the body, particularly in the head, neck, and scalp. Patients who have undergone previous radiation treatment or who have chronic lymphedema also face an elevated risk of this condition. Various genetic changes are suspected to contribute to the development of angiosarcoma, and these changes have been identified as potential targets for treatment. For localized disease, wide surgical resection is often the prudent course of action. A multidisciplinary approach, which may include surgery, radiotherapy, systemic chemotherapy, or immunotherapy, is typically the most effective way to achieve favorable outcomes. In this review, we discuss the general understanding of angiosarcoma and its management, with a particular focus on the current evolving treatments for the disease.

Target gene regulatory network of miR-497 in angiosarcoma

Angiosarcoma (AS) is a vascular sarcoma that is highly aggressive and metastatic. Due to its rarity, treatment options for patients are limited, therefore more research is needed to identify possible therapeutic vulnerabilities. We previously found that conditional deletion of Dicer1 drives AS development in mice. Given the role of DICER1 in canonical microRNA (miRNA) biogenesis, this suggests that miRNA loss is important in AS development. After testing miRNAs previously suggested to have a tumor-suppressive role in AS, microRNA-497-5p (miR-497) suppressed cell viability most significantly. We also found that miR-497 overexpression led to significantly reduced cell migration and tumor formation. To understand the mechanism of miR-497 in tumor suppression, we identified clinically relevant target genes using a combination of RNA-sequencing data in an AS cell line, expression data from AS patients, and target prediction algorithms. We validated miR-497 direct regulation of CCND2, CDK6, and VAT1. One of these genes, VAT1, is an understudied protein that has been suggested to promote cell migration and metastasis in other cancers. Indeed, we find that pharmacologic inhibition of VAT1 with the natural product Neocarzilin A reduces AS migration. This work provides insight into the mechanisms of miR-497 and its target genes in AS pathogenesis.

Breast Sarcomas, Phyllodes Tumors, and Desmoid Tumors: Turning the Magnifying Glass on Rare and Aggressive Entities

Breast sarcomas (BSs), phyllodes tumors (PTs), and desmoid tumors (DTs) are rare entities that arise from connective tissue. BSs can be classified as either primary or secondary, whether they develop de novo or after radiation exposure or lymphedema. PIK3CA seems to play an important common role in different BS. Malignant PTs show similar behavior to BSs, while DTs are locally aggressive but rarely metastasize. BSs usually present as unilateral, painless, rapidly growing masses with rare nodal involvement. The diagnosis should be based on magnetic resonance imaging and a core needle biopsy. Staging should comprise a chest computed tomography (CT) scan (except for benign PT and DT), while abdominal and pelvic CT scans and bone scans should be added in certain subtypes. The mainstay of treatment for localized BS is surgery, with margin goals that vary according to subtype. Radiotherapy and chemotherapy can be used as neoadjuvant or adjuvant approaches, but their use in these settings is not standard. Advanced BS should be treated with systemic therapy, consistent with recommendations for advanced soft tissue sarcomas of other topographies. Given the rarity and heterogeneity of these entities, multidisciplinary and multi-institutional collaboration and treatment at reference centers are critical.

Overcoming Barriers to Tumor Genomic Profiling through Direct-to-Patient Outreach

PURPOSE

To overcome barriers to genomic testing for patients with rare cancers, we initiated a program to offer free clinical tumor genomic testing worldwide to patients with select rare cancer subtypes.

EXPERIMENTAL DESIGN

Patients were recruited through social media outreach and engagement with disease-specific advocacy groups, with a focus on patients with histiocytosis, germ cell tumors (GCT), and pediatric cancers. Tumors were analyzed using the MSK-IMPACT next-generation sequencing assay with the return of results to patients and their local physicians. Whole-exome recapture was performed for female patients with GCTs to define the genomic landscape of this rare cancer subtype.

RESULTS

A total of 333 patients were enrolled, and tumor tissue was received for 288 (86.4%), with 250 (86.8%) having tumor DNA of sufficient quality for MSK-IMPACT testing. Eighteen patients with histiocytosis have received genomically guided therapy to date, of whom 17 (94%) have had clinical benefit with a mean treatment duration of 21.7 months (range, 6-40+). Whole-exome sequencing of ovarian GCTs identified a subset with haploid genotypes, a phenotype rarely observed in other cancer types. Actionable genomic alterations were rare in ovarian GCT (28%); however, 2 patients with ovarian GCTs with squamous transformation had high tumor mutational burden, one of whom had a complete response to pembrolizumab.

CONCLUSIONS

Direct-to-patient outreach can facilitate the assembly of cohorts of rare cancers of sufficient size to define their genomic landscape. By profiling tumors in a clinical laboratory, results could be reported to patients and their local physicians to guide treatment. See related commentary by Desai and Subbiah, p. 2339.

Tumor Microenvironment and Its Clinicopathologic and Prognostic Association in Cutaneous and Noncutaneous Angiosarcomas

OBJECTIVES

We explored features of the angiosarcoma (AS) tumor microenvironment to discover subtypes that may respond to immunotherapy.

METHODS

Thirty-two ASs were included. Tumors were studied by histology, immunohistochemistry (IHC), and gene expression profile using the HTG EdgeSeq Precision Immuno-Oncology Assay.

RESULTS

Comparing cutaneous and noncutaneous ASs, the second group showed 155 deregulated genes, and unsupervised hierarchical clustering (UHC) delineated two groups: the first mostly cutaneous AS and the second mainly noncutaneous AS. Cutaneous ASs showed a significantly higher proportion of T cells, natural killer cells, and naive B cells. ASs without MYC amplification revealed a higher immunoscore in comparison with ASs with MYC amplification. PD-L1 was significantly overexpressed in ASs without MYC amplification. UHC showed 135 deregulated genes differentially expressed when comparing ASs from the non-head and neck area with patients who had AS in the head and neck area. ASs from the head and neck area showed high immunoscore. PD1/PD-L1 content was significantly more highly expressed in ASs from the head and neck area. IHC and HTG gene expression profiling revealed a significant correlation between PD1, CD8, and CD20 protein expression but not PD-L1.

CONCLUSIONS

Our HTG analyses confirmed a high degree of tumor and microenvironment heterogeneity. Cutaneous ASs, ASs without MYC amplification, and ASs located in the head and neck area seem to be the most immunogenic subtypes in our series.

Treatment of radiation-associated angiosarcoma

PURPOSE OF REVIEW

Radiation-associated angiosarcoma is a cutaneous aggressive tumor that is very rare and it represents a specific entity poorly studied in literature. It requires new therapeutic opportunity.

RECENT FINDINGS

The complete surgical resection with negative margins is the mainstay treatment of localized treatment, even though it is difficult to reach in case of diffuse cutaneous infiltration. Adjuvant re-irradiation may improve local control with no benefit demonstrated on survival. Many systemic treatments can be efficient not only in metastatic setting but also in neoadjuvant setting in case of diffuse presentation. These treatments have never been compared to each other; the most efficient regimen remains to be determined, and a high heterogeneity of treatment is observed, even between sarcoma reference centers.

SUMMARY

Immune therapy represents the most promising treatment under development. At the time of building clinical trial to assess the efficacy of immune therapy, the lack of randomized studies prevents the identification of a strong and consensual reference arm treatment. Given the rarity of the disease, only international collaborative clinical trials may have a chance to include enough patients to draw any conclusion and so will have to counteract the heterogeneity of management.

Histological and immunohistochemical prognostic factors of primary angiosarcoma

Angiosarcoma is a malignant vascular endothelial neoplasm with various histological patterns. Despite its highly malignant potential, histological prognostic prediction has not been adopted for angiosarcoma. This study aimed to establish a method of predicting the prognosis of primary angiosarcoma. Formalin-fixed, paraffin-embedded samples from 104 primary angiosarcomas were prepared. All the cases were reviewed based on histological examinations with H&E staining. Because the French Fédération Nationale des Centres de Lutte Contre Le Cancer system (FNCLCC) is not adopted for angiosarcoma, we experimentally established a modified version of FNCLCC. Immunohistochemical staining for ERG, CD31, CD34, D2-40, HHV-8, p16, C-MYC, and p53 was performed. Fluorescence in situ hybridization (FISH) was performed for 31 cases to assay c-MYC gene amplification. Multivariate analysis revealed that age (> 70 years old) (p = 0.0011), non-cutaneous angiosarcoma (p = 0.0265), metastasis on diagnosis (p < 0.0001), size ≥ 5 cm (p = 0.0388), no taxane chemotherapy (p = 0.0388), strong nuclear atypia (p = 0.0087), and the presence of luminal structure in ≥ 50% of the tumor volume (p = 0.0009) were independent poor prognostic factors. Among angiosarcomas with luminal formation, mFNCLCC scores were significantly correlated with a poorer prognosis. The overexpression of p16 was associated with less luminal formation (p = 0.0192). Immunohistochemical analysis of C-MYC showed a moderate level of concordance with FISH (Kappa value = 0.45). This study suggested that luminal formation and nuclear atypia may be poor histological prognostic factors of angiosarcoma and that mFNCLCC would be useful for predicting the prognosis of angiosarcoma with luminal formation.

The National COVID Cancer Antibody Survey: a hyper-accelerated study proof of principle for cancer research

The COVID-19 pandemic has led to a range of novel and adaptive research designs. In this perspective, we use our experience coordinating the National COVID Cancer Antibody Survey to demonstrate how a balance between speed and integrity can be achieved within a hyper-accelerated study design. Using the COVID-19 pandemic as an example, we show this approach is necessary in the face of uncertain and evolving situations wherein reliable information is needed in a timely fashion to guide policy. We identify streamlined participant involvement, healthcare systems integration, data architecture and real-world real-time analytics as key areas that differentiate this design from traditional cancer trials, and enable rapid results. Caution needs to be taken to avoid the exclusion of patient subgroups without digital access or literacy. We summarise the merits and defining features of hyper-accelerated cancer studies.

Association between hepatic angiosarcoma and end-stage renal disease: nationwide population-based evidence and enriched mutational signature of aristolochic acid exposure

Hepatic angiosarcoma (HAS) is an aggressive mesenchymal malignancy that remains underexplored with respect to its etiology and mutational landscapes. To clarify the association between HAS and end-stage renal disease (ESRD), we used nationwide data of the National Health Insurance Research Database (NHIRD) in Taiwan, covering ~99% of the population, from 2001 to 2016. To investigate molecular signatures, we performed whole-exome sequencing (WES) in 27 surgical specimens, including nine ESRD-associated cases. The NHIRD analysis demonstrated that HAS ranked second among all angiosarcomas in Taiwan, with the incidence rates of HAS being 0.08, 2.49, and 5.71 per 100,000 person-years in the general population, chronic kidney disease (CKD), and ESRD patients, respectively. The standardized incidence ratios of HAS in CKD and ESRD patients were 29.99 and 68.77, respectively. In comparison with nonhepatic angiosarcoma, the multivariate regression analysis of our institutional cohort confirmed CKD/ESRD as an independent risk factor for HAS (odds ratio: 9.521, 95% confidence interval: 2.995-30.261, p < 0.001). WES identified a high tumor mutation burden (TMB; median: 8.66 variants per megabase) and dominant A:T-to-T:A transversion in HAS with frequent TP53 (81%) and ATRX (41%) mutations, KDR amplifications/gains (56%), and CDKN2A/B deletions (48%). Notably, ESRD-associated HAS had a significantly higher TMB (17.62 variants per megabase, p = 0.01) and enriched mutational signatures of aristolochic acid exposure (COSMIC SBS22, p < 0.001). In summary, a significant proportion of HAS in Taiwan is associated with ESRD and harbors a distinctive mutational signature, which concomitantly links nephrotoxicity and mutagenesis resulting from exposure to aristolochic acid or related compounds. A high TMB may support the eligibility for immunotherapy in treating ESRD-associated HAS. © 2023 The Pathological Society of Great Britain and Ireland.

Spatial transcriptomics reveal topological immune landscapes of Asian head and neck angiosarcoma

Angiosarcomas are rare malignant tumors of the endothelium, arising commonly from the head and neck region (AS-HN) and recently associated with ultraviolet (UV) exposure and human herpesvirus-7 infection. We examined 81 cases of angiosarcomas, including 47 cases of AS-HN, integrating information from whole genome sequencing, gene expression profiling and spatial transcriptomics (10X Visium). In the AS-HN cohort, we observed recurrent somatic mutations in CSMD3 (18%), LRP1B (18%), MUC16 (18%), POT1 (16%) and TP53 (16%). UV-positive AS-HN harbored significantly higher tumor mutation burden than UV-negative cases (p = 0.0294). NanoString profiling identified three clusters with distinct tumor inflammation signature scores (p < 0.001). Spatial transcriptomics revealed topological profiles of the tumor microenvironment, identifying dominant but tumor-excluded inflammatory signals in immune-hot cases and immune foci even in otherwise immune-cold cases. In conclusion, spatial transcriptomics reveal the tumor immune landscape of angiosarcoma, and in combination with multi-omic information, may improve implementation of treatment strategies.

[Rare tumors: Angiosarcoma]

Angiosarcomas are a rare subtype representing 1-2% of soft tissue sarcomas. Risk factors are rarely elucidated but radiotherapy and lymphedema are the most common ones, usually following local treatment for local breast cancer. Despite the improvement of our knowledge, the prognosis remains poor with 35-40% of 5 year-overall survival. Local treatment when feasible should include a R0 surgery completed with adjuvant radiation. When metastatic, front lines chemotherapies include doxorubicine or weekly paclitaxel. If possible, in oligometastatic patients, metastasectomy should always be considered allowing the best responses. The knowledge of angiosarcoma's biology is rapidly increasing and new biomarkers are emerging. The use of immunotherapy in particular subtypes including head and neck angiosarcomas shows promising results. The model of the angiosarcoma project, a patient-participating study, seems to be an excellent way to study rare tumors. We should focus our efforts on understanding the underlying molecular biology to propose the best precision medicine for those patients.

Naturally occurring canine sarcomas: Bridging the gap from mouse models to human patients through cross-disciplinary research partnerships

Fueled by support from the National Cancer Institute's "Cancer Moonshot" program, the past few years have witnessed a renewed interest in the canine spontaneous cancer model as an invaluable resource in translational oncology research. Increasingly, there is awareness that pet dogs with cancer provide an accessible bridge to improving the efficiency of cancer drug discovery and clinical therapeutic development. Canine tumors share many biological, genetic, and histologic features with their human tumor counterparts, and most importantly, retain the complexities of naturally occurring drug resistance, metastasis, and tumor-host immune interactions, all of which are difficult to recapitulate in induced or genetically engineered murine tumor models. The utility of canine models has been particularly apparent in sarcoma research, where the increased incidence of sarcomas in dogs as compared to people has facilitated comparative research resulting in treatment advances benefitting both species. Although there is an increasing awareness of the advantages in using spontaneous canine sarcoma models for research, these models remain underutilized, in part due to a lack of more permanent institutional and cross-institutional infrastructure to support partnerships between veterinary and human clinician-scientists. In this review, we provide an updated overview of historical and current applications of spontaneously occurring canine tumor models in sarcoma research, with particular attention to knowledge gaps, limitations, and growth opportunities within these applications. Furthermore, we propose considerations for working within existing veterinary translational and comparative oncology research infrastructures to maximize the benefit of partnerships between veterinary and human biomedical researchers within and across institutions to improve the utility and application of spontaneous canine sarcomas in translational oncology research.

Cutaneous angiosarcoma: A review of current evidence for treatment with checkpoint inhibitors

Cutaneous angiosarcoma (cAS) is a rare and aggressive subtype of soft tissue sarcoma with poor prognosis and suboptimal treatment options. Clinical presentation is variable, but cAS often arises from the head and neck. The most widely accepted current approach, surgical excision with adjuvant radiotherapy, is associated with high recurrence rates and can leave patients with profound disfigurement. Chemotherapy and targeted therapy alternatives have had limited success. Thus, there is a significant unmet need to address the absence of durable treatments for advanced and metastatic cAS. Like melanoma and cutaneous squamous cell carcinoma, tumor types with known response to immunotherapy, cAS harbors immune biomarkers, such as tumor mutational burden high (TMB-H), PD-L1 positivity, ultraviolet signature expression, and tertiary lymphoid structures. While data on the use and efficacy of immunotherapy in cAS is limited, the biomarkers suggest a promising advancement in future treatment options. This review aims to summarize and discuss current data from case reports, case series, retrospective studies and clinical trials regarding immunotherapy treatment and outcomes for cAS.

Anti-PD-1 therapy in advanced sarcomas: is cutaneous primary site a stronger predictor of response than histologic subtype?

BACKGROUND

Immune checkpoint inhibitors (ICIs) have shown modest antitumor activity in unselected advanced sarcomas. Histology driven approach to patient selection is the current standard for off-label anti-programmed cell death 1 (PD1) immunotherapy use.

METHODS

We retrospectively reviewed the clinical characteristics and outcomes of patients with advanced sarcoma who were treated with off label anti-PD1 immunotherapy at our center.

RESULTS

A total of 84 patients with 25 histological subtypes were included. Nineteen patients (23%) had a cutaneous primary tumor site. Eighteen patients (21%) were classified as having clinical benefit, including 1 patient with complete response, 14 with partial response, and 3 with stable disease lasting over 6 months with previously progressive disease. Cutaneous primary site location was associated with higher clinical benefit rate (58% vs. 11%, p < 0.001), longer median PFS (8.6 vs. 2.5 months, p = 0.003) and OS (19.0 vs. 9.2 months, p = 0.011), compared to non-cutaneous primary. Patients with histological subtypes that pembrolizumab is indicated per current National Comprehensive Cancer Network guidelines had modestly higher rate of clinical benefit versus other histologies, however, the difference was statistically insignificant (29% vs. 15%, p = 0.182) and no statistically significant difference in PFS or OS was observed between these groups. Immune-related adverse events were more frequently seen among patients with clinical benefit (72% vs. 35%, p = 0.007).

CONCLUSIONS

Anti-PD1-based immunotherapy is highly efficacious in advanced sarcomas of cutaneous primary site. Cutaneous primary site location is a stronger predictor of ICI response than histologic subtype and should be accounted for in treatment guidelines and clinical trial design.

Immunotherapy for Soft Tissue Sarcomas: Anti-PD1/PDL1 and Beyond

Sarcomas gather a heterogeneous group of mesenchymal malignant tumors including more than 150 different subtypes. Most of them represent aggressive tumors with poor prognosis at the advanced stage, despite the better molecular characterization of these tumors and the development of molecular-driven therapeutic strategies. During the last decade, immunotherapy has been developed to treat advanced cancers, mainly thanks to immune checkpoint inhibitors (ICI) such as anti-PD1/PDL1 and later to adoptive immune cell therapies. In this review, we aim to summarize the state of the art of immunotherapy in soft tissue sarcomas (STS). Overall, the clinical trials of ICI that included a wide diversity of STS subtypes reported limited efficacy with some outlying responders. Both emerging biomarkers are of interest in selecting good candidates and in the development of combination therapies. Finally, the recent breakthroughs of innovative adoptive therapies in STS seem highly promising.