Clinicopathologic and molecular correlates to neoadjuvant chemotherapy-induced pathologic response in breast angiosarcoma.

Both primary and secondary breast angiosarcoma (AS) are characterized by multifocal presentation and aggressive behavior. Despite multimodality therapy, local and distant relapse rates remain high. Therefore, neoadjuvant chemotherapy (NACT) is employed to improve the R0 resection rates and survival, but its benefits remain controversial. Herein, we investigate pathologic and molecular correlates to NACT-induced histologic response in a group of 29 breast AS, 4 primary and 25 radiation-associated (RA). The two NACT regimens applied were anthracycline- and non-anthracycline-based. The pathologic response grade was defined as: I: ≤ 50%, II: 51%-90%, III: 91%-99%, and IV: 100%. An additional 45 primary AS and 102 RA-AS treated by surgery alone were included for survival comparison. The genomic landscape was analyzed in a subset of cases and compared to a cohort of AS without NACT on a paired tumor-normal targeted DNA NGS platform. All patients were females, with a median age of 31 years in primary AS and 68 years in RA-AS. All surgical margins were negative in NACT group. The NACT response was evenly divided between poor (Grades I-II; n = 15) and good responders (Grades III-IV; n = 14). Mitotic count >10/mm2 was the only factor inversely associated with pathologic response. By targeted NGS, all 10 post-NACT RA-AS demonstrated MYC amplification, while both primary AS harbored KDR mutations. TMB or other genomic alterations did not correlate with pathologic response. All four patients with Grade IV response remained free of disease. The good responders had a significantly better disease-specific survival (p = 0.04). There was no survival difference with NACT status or the NACT regimens applied. However, NACT patients with MYC-amplified tumors showed better disease-free survival (p = 0.04) compared to MYC-amplified patients without NACT. The overall survival of NACT group correlated with size >10 cm (p = 0.02), pathologic response (p = 0.04), and multifocality (p = 0.01) by univariate, while only size >10 cm (p = 0.03) remained significant by multivariate analysis.

Metastasizing aneurysmal dermatofibroma initially diagnosed as angiosarcoma confirmed by CD63::PRKCD fusion gene detection with nanopore sequencing.

Dermatofibroma (DF) is a benign tumor that forms pedunculated lesions ranging in size from a few millimeters to 2 cm, usually affecting the extremities and trunks of young adults. Histopathologically, DF is characterized by the storiform proliferation of monomorphic fibroblast-like spindle cells. In addition to neoplastic cells, secondary elements such as foamy histiocytes, Touton-type giant cells, lymphoplasmacytes, and epidermal hyperplasia are characteristic histological features. Several histological variants, including atypical, cellular, aneurysmal, and lipidized variants, have been reported; cases with variant histologies are sometimes misdiagnosed as sarcomas. We present a case of metastasizing aneurysmal DF that was initially diagnosed as an angiosarcoma on biopsy. A 26-year-old woman was referred to our hospital with a gradually enlarging subcutaneous mass in her lower left leg. Positron emission tomography-computed tomography revealed high fluorodeoxyglucose uptake not only in the tumor but also in the left inguinal region. On biopsy, ERG and CD31-positive atypical spindle cells proliferated in slit-like spaces with extravasation, leading to the diagnosis of angiosarcoma. Histology of the wide-resection specimen was consistent with DF, and lymph node metastasis was also observed. Nanopore DNA sequencing detected CD63::PRKCD fusion and copy number gain, although CD63 was not included in the target region of adaptive sampling. This report highlights the importance of recognizing the unusual clinical, radiological, and pathological features of DF to avoid misdiagnosis, and the potential diagnostic utility of nanopore sequencer.

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.

Treatment Monitoring of a Patient with Synchronous Metastatic Angiosarcoma and Breast Cancer Using ctDNA.

Angiosarcoma is a rare and aggressive type of soft-tissue sarcoma with high propensity to metastasize. For patients with metastatic angiosarcoma, prognosis is dismal and treatment options are limited. To improve the outcomes, identifying patients with poor treatment response at an earlier stage is imperative, enabling alternative therapy. Consequently, there is a need for improved methods and biomarkers for treatment monitoring. Quantification of circulating tumor-DNA (ctDNA) is a promising approach for patient-specific monitoring of treatment response. In this case report, we demonstrate that quantification of ctDNA using SiMSen-Seq was successfully utilized to monitor a patient with metastatic angiosarcoma. By quantifying ctDNA levels using 25 patient-specific mutations in blood plasma throughout surgery and palliative chemotherapy, we predicted the outcome and monitored the clinical response to treatment. This was accomplished despite the additional complexity of the patient having a synchronous breast cancer. The levels of ctDNA showed a superior correlation to the clinical outcome compared with the radiological evaluations. Our data propose a promising approach for personalized biomarker analysis to monitor treatment in angiosarcomas, with potential applicability to other cancers and for patients with synchronous malignancies.

The complete Kaposi sarcoma-associated herpesvirus genome induces early-onset, metastatic angiosarcoma in transgenic mice.

Kaposi sarcoma (KS) is the most common cancer in persons living with HIV. It is caused by KS-associated herpesvirus (KSHV). There exists no animal model for KS. Pronuclear injection of the 170,000-bp viral genome induces early-onset, aggressive angiosarcoma in transgenic mice. The tumors are histopathologically indistinguishable from human KS. As in human KS, all tumor cells express the viral latency-associated nuclear antigen (LANA). The tumors transcribe most viral genes, whereas endothelial cells in other organs only transcribe the viral latent genes. The tumor cells are of endothelial lineage and exhibit the same molecular pattern of pathway activation as KS, namely phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR, interleukin-10 (IL-10), and vascular endothelial growth factor (VEGF). The KSHV-induced tumors are more aggressive than Ha-ras-induced angiosarcomas. Overall survival is increased by prophylactic ganciclovir. Thus, whole-virus KSHV-transgenic mice represent an accurate model for KS and open the door for the genetic dissection of KS pathogenesis and evaluation of therapies, including vaccines.

New risk factors and molecular landscapes of hepatic angiosarcoma in the Taiwanese population†.

Hepatic angiosarcoma is a rare, highly aggressive malignancy of the liver. The tumorigenesis of hepatic angiosarcoma has been relatively understudied in terms of aetiology and molecular properties. A recent study published in The Journal of Pathology revealed a strong association between hepatic angiosarcoma incidence and chronic kidney disease, particularly in end-stage renal disease using population-based data from the National Health Insurance Research Database in Taiwan and an institutional cohort. The study also revealed enrichment in the mutational signature of aristolochic acid exposure and is the first reported observation of this mutational signature in human sarcomas. © 2023 The Pathological Society of Great Britain and Ireland.

Dysregulated miRNAs in a canine model of haemangiosarcoma metastatic to the brain.

Haemangiosarcoma is a highly metastatic and lethal cancer of blood vessel-forming cells that commonly spreads to the brain in both humans and dogs. Dysregulations in phosphatase and tensin (PTEN) homologue have been identified in various types of cancers, including haemangiosarcoma. MicroRNAs (miRNAs) are short noncoding single-stranded RNA molecules that play a crucial role in regulating the gene expression. Some miRNAs can function as oncogenes or tumour suppressors, influencing important processes in cancer, such as angiogenesis. This study aimed to investigate whether miRNAs targeting PTEN were disrupted in canine haemangiosarcoma and its corresponding brain metastases (BM). The expression levels of miRNA-10b, miRNA-19b, miRNA-21, miRNA-141 and miRNA-494 were assessed in samples of primary canine cardiac haemangiosarcomas and their matched BM. Furthermore, the miRNA profile of the tumours was compared to samples of adjacent non-cancerous tissue and healthy control tissues. In primary cardiac haemangiosarcoma, miRNA-10b showed a significant increase in expression, while miRNA-494 and miRNA-141 exhibited downregulation. Moreover, the overexpression of miRNA-10b was retained in metastatic brain lesions. Healthy tissues demonstrated significantly different expression patterns compared to cancerous tissues. In particular, the expression of miRNA-10b was nearly undetectable in both control brain tissue and perimetastatic cerebral tissue. These findings can provide a rationale for the development of miRNA-based therapeutic strategies, aimed at selectively treating haemangiosarcoma.

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.

Primary cardiac sarcomas: A clinicopathologic study in a single institution with 25 years of experience with an emphasis on MDM2 expression and adjuvant therapy for prognosis.

BACKGROUND: Primary cardiac sarcomas are rare and their clinicopathologic features are heterogeneous. Among them, particularly intimal sarcoma is a diagnostic challenge due to nonspecific histologic features. Recently, MDM2 amplification reported to be a characteristic genetic event in the intimal sarcoma. In this study, we aimed to identify the types and incidence of primary cardiac sarcomas that occurred over 25 years in tertiary medical institutions, and to find clinicopatholgical significance through reclassification of diagnoses using additional immunohistochemistry (IHC). METHODS: We reviewed the primary cardiac sarcoma cases between January 1993 and June 2018 at Asan Medical Center, South Korea, with their clinicopathologic findings, and reclassified the subtypes, especially using IHC for MDM2 and then, analyzed the significance of prognosis. RESULTS: Forty-eight (6.8%) cases of a primary cardiac sarcoma were retrieved. The tumors most frequently involved the right atrium (n = 25, 52.1%), and the most frequent tumor subtype was angiosarcoma (n = 23, 47.9%). Seven cases (53.8%) were newly reclassified as an intimal sarcoma by IHC for MDM2. Twenty-nine (60.4%) patients died of disease (mean, 19.8 months). Four patients underwent a heart transplantation and had a median survival of 26.8 months. This transplantation group tended to show good clinical outcomes in the earlier stages, but this was not statistically significant (p = 0.318). MDM2 positive intimal sarcoma showed the better overall survival (p = 0.003) than undifferentiated pleomorphic sarcoma. Adjuvant treatment is beneficial for patient survival (p < 0.001), particularly in angiosarcoma (p < 0.001), but not in intimal sarcoma (p = 0.154). CONCLUSION: Our study supports the use of adjuvant treatment in primary cardiac sarcoma, as it was associated with a significantly better overall survival rate. Further consideration of tumor histology may be important in determining the optimal use of adjuvant treatment for different types of sarcomas. Therefore, accurate diagnosis by MDM2 test is important condsidering patient's prognosis and treatment.

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.

[Primary cardiac angiosarcoma: a clinicopathological and molecular genetic analysis of thirteen cases].

Objective: To investigate the clinicopathological and molecular features of primary cardiac angiosarcoma (PCAS), and to analyze the correlation between KDR mutation and the clinicopathological features of PCAS. Methods: Thirteen cases of PCAS were collected at Beijing Anzhen Hospital, Capital Medical University from January 2007 to December 2021. The clinicopathological features, diagnosis, differential diagnosis and outcome were retrospectively analyzed. KDR mutation was detected by next-generation sequencing (NGS) and then the expression of KDR (VEGFR2) was determined by immunohistochemistry (IHC), with review of relevant literatures. Results: There were eight males and five females with a mean age of 45 years. The primary tumor was in the right atrium in 10 cases, left atrium in two cases and right ventricle in one case. The histomorphology was mainly poorly differentiated angiosarcoma (11 cases), with highly pleomorphic spindle or round cells in solid sheets, brisk mitotic activity and extensive necrosis. Vascular lumen formation was observed in two cases of high to moderate differentiation, and biphenotypic differentiation was seen in five cases. IHC staining showed CD34, CD31, Fli1, ERG and vimentin were diffusely positive, pan-cytokeratin was positive, Ki-67 index ranged from 3% to 90%, which was positively correlated with the differentiation degree and grade of the PCASs (P<0.05). At the end of follow-up period, one patient was alive, two patients were lost to follow-up, and the remaining 10 patients had an average survival time of 4.6 months. Finally, NGS sequencing was performed on seven samples after screening, and the results showed that KDR and NF1 mutations were both present in three cases. VEGFR2 expression had no significant correlation with the differentiation degree and grade of PCAS (P>0.05), and it was not related to KDR mutation. Conclusions: PCASs mainly occur in the right atrium, and are mainly poorly differentiated. Ki-67 index is helpful to assess the degree and grade of tumor differentiation. The occurrence and development of PCAS may be related to the pathway involved in KDR mutation, but KDR mutation has no clear correlation with clinicopathological characteristics of PCAS, and immunohistochemical staining can not replace gene detection to determine whether the tumor had KDR mutation.

New molecular targets in canine hemangiosarcoma-Comparative review and future of the precision medicine.

Human angiosarcoma and canine hemangiosarcoma reveal similarities not only in their aggressive clinical behaviour, but especially in molecular landscape and genetic alterations involved in tumorigenesis and metastasis formation. Currently, no satisfying treatment that allows for achieving long overall survival or even prolonged time to progression does not exist. Due to the progress that has been made in targeted therapies and precision medicine the basis for a new treatment design is to uncover mutations and their functions as possible targets to provide tailored drugs for individual cases. Whole exome or genome sequencing studies and immunohistochemistry brought in the last few years important discoveries and identified the most common mutations with probably crucial role in this tumour development. Also, despite a lack of mutation in some of the culprit genes, the cancerogenesis cause may be buried in main cellular pathways connected with proteins encoded by those genes and involving, for example, pathological angiogenesis. The aim of this review is to highlight the most promising molecular targets for precision oncology treatment from the veterinary perspective aided by the principles of comparative science. Some of the drugs are only undergoing laboratory in vitro studies and others entered the clinic in the management of other cancer types in humans, but those used in dogs with promising responses have been mentioned as priorities.

Distinct genomic landscapes in radiation-associated angiosarcoma compared with other radiation-associated sarcoma histologies.

MYC amplifications have been frequently detected in radiation (RT)-associated angiosarcomas (ASs) by low-resolution molecular methods. However, large-scale next-generation sequencing (NGS) studies to investigate the genomic landscape of RT-AS are scarce, particularly compared with other RT-associated sarcomas. We performed a detailed comparative genomic investigation of RT-AS versus other RT-associated histotypes, as well as sporadic sarcomas with similar histologies. Our institutional targeted DNA-NGS assay database was searched for RT-associated sarcomas. Clinical outcome data, pathologic diagnosis, and the types and frequencies of genomic alterations, including single nucleotide variants (SNVs) and copy number alterations (CNAs), were analyzed. The cohort consisted of 82 patients, 68 (83%) females and 14 (17%) males, aged 37-88 (mean 64) years. Forty-four RT-ASs (38 from breast) and 38 RT sarcomas of other histologies, including 12 malignant peripheral nerve sheath tumors (RT-MPNSTs), 14 undifferentiated pleomorphic sarcomas (RT-UPSs), and 12 osteosarcomas (RT-OSs), were included. Median time intervals from radiation to initial diagnosis in RT-AS (8.0 years) were significantly lower than those in RT-MPNST and RT-UPS (12.5 and 18.5 years), respectively. Each RT-sarcoma histotype harbored distinct mutations and CNAs. RT-associated AS had more frequent MYC, FLT4, CRKL, HRAS, and KMT2D alterations than sporadic AS (enriched in TP53, KDR, ATM, ATRX), whereas the mutational landscapes of MPNST, UPS, and OS were similar in both RT and non-RT settings. CDKN2A/B deletions and TP53 alterations were infrequent in RT-AS compared with other RT sarcomas. Among RT sarcomas, RT-AS harbored the lowest fraction of genome altered (FGA), while RT-MPNST showed the highest FGA. RT-AS had the lowest insertion:SNV and deletion:SNV ratios, while RT-UPS had the highest. The predominant mutational signatures were associated with errors in DNA repair and replication. In conclusion, RT-AS has a distinct genomic landscape compared with other RT sarcomas and sporadic AS. Potential molecular targets for precision medicine may be histotype-dependent. © 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.

Primary and secondary angiosarcomas of the liver: a multi-institutional study of 32 cases.

Angiosarcomas involving the liver can be hepatic primary or metastasis from another anatomic site, which have not been systematically compared. We analyzed a series of liver biopsy or resection specimens carrying a diagnosis of angiosarcoma collected between 2005 and 2022 at 3 tertiary medical centers. The cohort included 32 patients (20 M and 12 F) with a median age of 64 years. Nineteen were primary hepatic angiosarcoma (PHA) and 13 metastatic angiosarcoma to liver (MA). Males were predominant in PHA (15/19, 78%) compared to MA (5/13, 38%, P = .025). There was no age difference between the 2 groups. Five cases had background hepatic cirrhosis, which more likely harbored PHA (4/5, 80%). Multifocality and multiorgan involvement were common in both groups. Tumor size was significantly larger in PHA than in MA (10.4 versus 4.7 cm, P < .01). Histologically, there were no differences in terms of tumor morphology (spindled versus epithelioid) and growth patterns (vasoformative versus solid) between the 2 groups. Immunohistochemically, all tumor cells were positive for CD31 (28/28, 100%) and ERG (18/18, 100%). Molecular analysis in 5 cases demonstrated different mutation profiles involving different genes, including MTOR, PIK3CA, ARID1A, CDKN2A, PTEN, TP53, ATRX, KDR/VEGFR2, and so forth. On follow-up, 30 patients (93%) died of disease, with a median survival of 114 days. Univariate and multivariate analyses revealed PHA and epithelioid morphology to be associated with worse survival (P < .05), while treatment was associated with better survival (P < .001). Our results confirmed that angiosarcoma, particularly PHA, is extremely aggressive. Epithelioid morphology is an adverse prognosticator and may be used for tumor subclassification.

Contemporary diagnostic approach to atypical vascular lesion and angiosarcoma.

Vascular neoplasms account for a substantial fraction of cutaneous mesenchymal tumors, spanning from clinically indolent benign lesions to highly aggressive malignancies. These neoplasms present a distinctive challenge in terms of their diagnostic histopathology, both because of the breadth of their morphological manifestations and because of the significant histological overlap between different entities, even benign and malignant ones. The post-radiotherapy setting is particularly problematic diagnostically, insofar as radiation exposure predisposes not only to secondary angiosarcoma, but also to atypical vascular lesion, a largely benign proliferation of cutaneous blood vessels typically affecting the breast. To address these challenges, we explore the clinical, histological, and molecular features of malignant vascular neoplasia, including primary and secondary subtypes, through the comparative lens of atypical vascular lesion. In addition to highlighting the key morphological indicators of malignancy in superficial vasoformative tumors, we offer an approach that integrates clinical characteristics and molecular genetic profiling to facilitate accurate classification. With this current knowledge as our foundation, we also look ahead in an effort to frame some of the key unanswered questions regarding superficial vascular malignancies and their natural history, clinical management, and molecular underpinnings.

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.

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.