Prognostic Factors in Epithelioid Hemangioendothelioma: Analysis of a Nationwide Molecularly/Immunohistochemically Confirmed Cohort of 57 Cases.

Epithelioid hemangioendothelioma (EHE) is an extremely rare vascular sarcoma with variable aggressive clinical behavior. In this retrospective study, we aimed to investigate prognostic factors based on clinicopathologic findings in a molecularly/immunohistochemically confirmed nationwide multicenter cohort of 57 EHE cases. Patients had unifocal disease (n = 29), multifocal disease (n = 5), lymph node metastasis (n = 8) and/or distant metastasis (n = 15) at the time of diagnosis. The overall survival rate was 71.4% at 1 year and 50.7% at 5 years. Survival did not correlate with sex, age or histopathological parameters. No survival differences were observed between multifocal and metastatic disease, suggesting that multifocality represents early metastases and treatment options are limited in comparison to unifocal disease. In unifocal tumors, survival could be predicted using the risk stratification model of Shibayama et al., dividing the cases into low- (n = 4), intermediate- (n = 15) and high- (n = 3) risk groups. No clinical or histopathological parameters were associated with progressive unifocal disease course. Lymph node metastases at the time of diagnosis occurred in 14.0% of the cases and were mainly associated with tumor localization in the head and neck area, proposing lymph node dissection. In conclusion, our results demonstrate the aggressive behavior of EHE, emphasize the prognostic value of a previously described risk stratification model and may provide new insights regarding tumor focality, therapeutic strategies and prognosis.

Establishment and characterization of the first patient-derived radiation-induced angiosarcoma xenograft model (RT-AS5).

Angiosarcomas are a heterogeneous group of rare endothelial malignancies with a complex, not completely unravelled biology. They encompass primary (sporadically occurring) angiosarcomas of several origins and secondary angiosarcomas, which often arise due to DNA damaging factors including radiotherapy or ultraviolet light exposure. The optimal treatment of metastatic angiosarcomas is unclear and the prognosis is poor. In order to discover novel treatment strategies for angiosarcomas it is important to take the heterogeneity of these tumors into account. For this reason it is also important to have preclinical models available for the different clinical subtypes. Owing to the rarity of angiosarcomas, models are scarce. So far, only five human cell lines of angiosarcomas (all of the scalp after UV exposure) are available worldwide. In this paper we describe a novel established patient-derived xenograft model of a radiotherapy-induced angiosarcoma of the breast. The tumor was characterized by a MYC amplification, CD31 and ERG immunohistochemical positivity and was further characterized by using next generation sequencing (TruSight Oncology 500) in combination with the R-package XenofilteR to separate mouse from human sequence reads.

Immunological and Genomic Analysis Reveals Clinically Relevant Distinctions between Angiosarcoma Subgroups.

Angiosarcomas (AS) are extremely rare and aggressive vascular malignancies subdivided in de novo primary AS (pAS) and secondary AS (sAS). We hypothesize that the combination of immunological and genomic profiles significantly differs between primary and secondary AS, with potential impact on treatment strategies and a role for immunotherapy. Tumor-infiltrating lymphocytes were analyzed using multiplex immunohistochemistry from 79 pAS and 178 sAS. Median cell density was significantly higher in sAS for CD3+ T-cells (p < 0.001), CD8+ cytotoxic T-cells (p = 0.033), CD4+ T-helper cells (p < 0.001) and FoxP3+ T-regulatory cells (p < 0.001). CD20+ B-cell density was comparable (p = 0.417). Comprehensive genomic profiling was performed in 25 pAS and 25 sAS. A (likely) pathogenic mutation was detected in 80% of pAS vs. 88% of sAS (p = 0.702). Amplifications were found in 15% of pAS vs. 84% of sAS (p < 0.001). DNA damage response (DDR) pathway mutations (p = 0.021) and MYC amplifications (p < 0.001) were predominantly seen in sAS. In conclusion we observed a clear and clinical relevant distinction in immune infiltration and genomic profiles between pAS and sAS. The T-cell infiltrated tumor microenvironment and frequent DDR gene mutations, especially in sAS, warrant clinical trials with immunotherapy.

PARP inhibition in UV-associated angiosarcoma preclinical models.

PURPOSE: Angiosarcoma (AS) is a rare vasoformative sarcoma, with poor overall survival and a high need for novel treatment options. Clinically, AS consists of different subtypes, including AS related to previous UV exposure (UV AS) which could indicate susceptibility to DNA damage repair inhibition. We, therefore, investigated the presence of biomarkers PARP1 (poly(ADP-ribose)polymerase-1) and Schlafen-11 (SLFN11) in UV AS. Based on experiences in other sarcomas, we examined (combination) treatment of PARP inhibitor (PARPi) olaparib and temozolomide (TMZ) in UV AS cell lines. METHODS: Previously collected UV AS (n = 47) and non-UV AS (n = 96) patient samples and two UV AS cell lines (MO-LAS and AS-M) were immunohistochemically assessed for PARP1 and SLFN11 expression. Both cell lines were treated with single agents PARPi olaparib and TMZ, and the combination treatment. Next, cell viability and treatment synergy were analyzed. In addition, effects on apoptosis and DNA damage were examined. RESULTS: In 46/47 UV AS samples (98%), PARP1 expression was present. SLFN11 was expressed in 80% (37/46) of cases. Olaparib and TMZ combination treatment was synergistic in both cell lines, with significantly increased apoptosis compared to single agent treatment. Furthermore, a significant increase in DNA damage marker γH2AX was present in both cell lines after combination therapy. CONCLUSION: We showed combination treatment of olaparib with TMZ was synergistic in UV AS cell lines. Expression of PARP1 and SLFN11 was present in the majority of UV AS tumor samples. Together, these results suggest combination treatment of olaparib and TMZ is a potential novel AS subtype-specific treatment option for UV AS patients.

Health-related quality of life and symptom burden of epithelioid hemangioendothelioma patients: a global patient-driven Facebook study in a very rare malignancy.

Purpose: Epithelioid hemangioendothelioma (EHE) is an ultra-rare vascular sarcoma with unique clinical features. EHE is characterized by an unpredictable, often protracted, clinical course and highly variable clinical presentation. Due to difficulty recruiting ultra-rare cancer patients, health-related quality of life (HRQoL) of EHE patients has not yet been studied. The aim of this study was to assess EHE symptom burden and its impact on HRQoL and psychological distress.Methods: The study was initiated after EHE patients' foundations approached our research group to study HRQoL. Patients were recruited from the international EHE Facebook group from May through October 2018. Data were collected using the online PROFILES registry. Latent class cluster analysis was performed to identify groups based on frequently reported symptoms. Differences in HRQoL (EORTC-QLQ-C30) and psychological distress (Hospital Anxiety and Depression Scale) between symptom-based clusters were examined.Results: Among 115 EHE patients from 20 countries, three clusters were identified, with low-, intermediate- and high-symptom burden, respectively. Highly symptomatic patients (33%) had clinically relevantly lower scores on HRQoL compared to the other two groups (p < 0.001). These patients suffered mostly from pain, insomnia and fatigue. Symptom burden significantly correlated with reduced daily functioning and high levels of psychological distress. Only for highly symptomatic patients, HRQoL and symptom levels were worse compared to healthy individuals.Conclusion: For the first time, we studied HRQoL in a large international cohort of ultra-rare cancer patients with distinct clinical characteristics, enabled by collaboration with patients and use of social media. We showed a considerable number of EHE patients were highly symptomatic, with a significant impact on HRQoL and psychological distress.

DNA Methylation Profiling Identifies Distinct Clusters in Angiosarcomas.

PURPOSE: DNA methylation profiling has previously uncovered biologically and clinically meaningful subgroups within many tumor types, but was not yet performed in angiosarcoma. Angiosarcoma is a rare sarcoma with very heterogeneous clinical presentations, which may be based on differences in biological background. In this exploratory study, DNA methylation profiling of 36 primary angiosarcoma samples from visceral, deep soft tissue, radiation-induced, and UV-induced localizations was performed. EXPERIMENTAL DESIGN: Primary angiosarcoma formalin-fixed paraffin-embedded samples from visceral, soft tissue, radiation-induced, and UV-induced origin were collected from a nationwide search for angiosarcoma in the Netherlands. DNA was extracted for methylation profiling with the Illumina Infinium MethylationEPIC array. Quality control assessment and unsupervised hierarchical clustering were performed. Copy-number profiles were generated and analyzed for chromosomal stability. Clinical data were obtained from the Netherlands Cancer Registry. RESULTS: DNA methylation profiling by unsupervised hierarchical clustering of 36 angiosarcoma samples (6 visceral, 5 soft tissue, 14 radiation-induced, 11 UV-induced) revealed two main clusters (A and B), which were divided into four subclusters. The clusters largely corresponded with clinical subtypes, showing enrichment of UV-induced cases in cluster A1 and radiation-induced cases in cluster A2. Visceral and soft tissue cases almost exclusively fell into cluster B. Cluster A showed significantly increased chromosomal instability and better overall survival (22 vs. 6 months, P = 0.046) compared with cluster B. CONCLUSIONS: In this novel methylation profiling study, we demonstrated for the first time four different angiosarcoma clusters. These clusters correlated with clinical subtype, overall survival, and chromosomal stability.

Prognostic Factors in a Large Nationwide Cohort of Histologically Confirmed Primary and Secondary Angiosarcomas.

Angiosarcoma (AS) is a rare sarcoma of endothelial origin, arising spontaneously (primary AS) or after external damage such as radiation therapy or UV exposure (secondary AS). To date, reliable assessment of prognostic factors has proven difficult, due to disease rarity and heterogeneity of study cohorts. Although large registries provide relatively large AS patient series, these cases often lack histological confirmation. This study aimed to analyze AS prognostic factors in a large nationwide cohort of histologically confirmed cases, established through linkage of clinical data from the Netherlands Cancer Registry and pathology data from the Dutch pathology registry (PALGA). All cases were reviewed by an expert pathologist, showing a 16% discordance rate. Multivariable Cox regression survival analysis among 479 confirmed AS patients revealed remarkably poorer overall survival (OS) for primary AS compared to secondary AS (7 vs 21 months, Hazard ratio (HR) = 1.5; 95% confidence interval (CI) = 1.2-1.9). Age above 65 years, male gender, and no surgical treatment also significantly correlated to worse OS. Overall, OS was relatively poor, with a median of 13 months (95% CI = 10-16 months) and 22% five-year survival rate. With this study, we illustrate AS heterogeneity in clinical behavior and show for the first time better survival for secondary AS compared to primary AS.

Expression and clinical association of programmed cell death-1, programmed death-ligand-1 and CD8+ lymphocytes in primary sarcomas is subtype dependent.

In order to explore the potential of immune checkpoint blockade in sarcoma, we investigated expression and clinical relevance of programmed cell death-1 (PD-1), programmed death ligand-1 (PD-L1) and CD8 in tumors of 208 sarcoma patients. Primary untreated osteosarcoma (n = 46), Ewing sarcoma (n = 32), alveolar rhabdomyosarcoma (n = 20), embryonal rhabdomyosarcoma (n = 77), synovial sarcoma (n = 22) and desmoplastic small round cell tumors (DSRCT) (n = 11) were examined immunohistochemically. PD-L1 expression was predominantly detected in alveolar and embryonal rhabdomyosarcomas (15% and 16%, respectively). In the alveolar subtype PD-L1 expression was associated with better overall, event-free and metastases-free survival. PD-1 expression on lymphocytes was predominantly seen in synovial sarcomas (18%). High levels of CD8+ lymphocytes were predominantly detected in osteosarcomas (35%) and associated with worse event-free survival in synovial sarcomas. Ewing sarcoma and DSRCTs showed PD-1 on tumor cells instead of on tumor infiltrating lymphocytes. Overall, expression and clinical associations were found to be subtype dependent. For the first time PD-1 expression on Ewing sarcoma (19%) and DSRCT (82%) tumor cells was described.