Comprehensive and Integrated Genomic Characterization of Adult Soft Tissue Sarcomas.

Sarcomas are a broad family of mesenchymal malignancies exhibiting remarkable histologic diversity. We describe the multi-platform molecular landscape of 206 adult soft tissue sarcomas representing 6 major types. Along with novel insights into the biology of individual sarcoma types, we report three overarching findings: (1) unlike most epithelial malignancies, these sarcomas (excepting synovial sarcoma) are characterized predominantly by copy-number changes, with low mutational loads and only a few genes (TP53, ATRX, RB1) highly recurrently mutated across sarcoma types; (2) within sarcoma types, genomic and regulomic diversity of driver pathways defines molecular subtypes associated with patient outcome; and (3) the immune microenvironment, inferred from DNA methylation and mRNA profiles, associates with outcome and may inform clinical trials of immune checkpoint inhibitors. Overall, this large-scale analysis reveals previously unappreciated sarcoma-type-specific changes in copy number, methylation, RNA, and protein, providing insights into refining sarcoma therapy and relationships to other cancer types.

brinker levels regulated by a promoter proximal element support germ cell homeostasis.

A limited BMP signaling range in the stem cell niche of the ovary protects against germ cell tumors and promotes germ cell homeostasis. The canonical repressor of BMP signaling in both the Drosophila embryo and wing disc is the transcription factor Brinker (Brk), yet the expression and potential role of Brk in the germarium has not previously been described. Here, we find that brk expression requires a promoter-proximal element (PPE) to support long-distance enhancer action as well as to drive expression in the germarium. Furthermore, PPE subdomains have different activities; in particular, the proximal portion acts as a damper to regulate brk levels precisely. Using PPE mutants as well as tissue-specific RNA interference and overexpression, we show that altering brk expression within either the soma or the germline affects germ cell homeostasis. Remarkably, we find that Decapentaplegic (Dpp), the main BMP ligand and canonical antagonist of Brk, is upregulated by Brk in the escort cells of the germarium, demonstrating that Brk can positively regulate this pathway.

Transcriptomic profiles of myxofibrosarcoma and undifferentiated pleomorphic sarcoma correlate with clinical and genomic features.

Myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS) are two common and aggressive subtypes of soft tissue sarcoma. The aim of this study was to assess potential transcriptomic differences between MFS and UPS tumours and to evaluate the extent to which differences in gene expression profiles were associated with genomic and clinical features. The study included 162 patients with tumours diagnosed as MFS (N = 62) or UPS (N = 100). The patients had been diagnosed and treated at two Swedish sarcoma centres during a 30-year period. For gene expression profiling and gene fusion detection all tumours were analysed using RNA-sequencing and could be compared with data on clinical outcome (N = 155), global copy number profiles (N = 145), and gene mutations (N = 128). Gene expression profiling revealed three transcriptomic clusters (TCs) without any clear separation of MFS and UPS. One TC was associated with longer metastasis-free survival. These tumours had lower tumour mutation burden (TMB), were enriched for a copy number signature representative of focal LOH and chromosomal instability on a diploid background, and were relatively immune-depleted. MFS and UPS showed extensive genomic overlap, with whole genome doubling occurring more frequently among the latter. The results support the idea that MFS and UPS tumours have largely overlapping genomic and transcriptomic features, with UPS tumours showing more aggressive behaviour and more complex genomes. Independently of the tumour type, clinically relevant subgroups were revealed by gene expression analysis, and the finding of multiple genomic subgroups strongly suggest the existence of subgroups of relevance to treatment stratification. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Expanding the molecular landscape of undifferentiated sarcomas of bone with a novel EWSR1-SSX3 gene fusion.

Undifferentiated sarcomas characterized by a primitive monomorphic round to spindle cell phenotype and often non-specific immunoprofile remain difficult to subclassify outside molecular analysis. The increased application of RNA sequencing in clinical practice led to significant advances and discoveries of novel gene fusions that furthered our understanding and refined classification of otherwise undifferentiated neoplasms. In this study, we report an undifferentiated round to spindle cell sarcoma arising in the femur of a 34-year-old female. The round to spindle tumor cells were arranged in short fascicles, with focal rosette formation, within a hyalinized stroma. The tumor immunoprofile included diffuse reactivity for CD99, SATB2, and TLE1 and patchy positivity for Cyclin D1, Keratin AE1/AE3, synaptophysin, and chromogranin. Other markers, such as EMA, SMA, desmin, S100, ERG, and WT1, were negative. Fluorescence in situ hybridization analysis for EWSR1 gene alterations showed a break-apart signal and targeted RNA sequencing revealed an EWSR1::SSX3 gene fusion. The patient received neoadjuvant chemotherapy followed by surgery and subsequently relapsed in less than a year with lung metastasis. Larger series are needed to determine if this fusion defines a novel subset of undifferentiated tumors or represents a genomic variant of already existing primitive round cell sarcoma categories, such as Ewing sarcoma or synovial sarcoma.

Pyrin Inflammasome Activation Defines Colchicine-Responsive SURF Patients from FMF and Other Recurrent Fevers.

Syndrome of undifferentiated recurrent fever (SURF) is characterized by recurrent fevers, a lack of confirmed molecular diagnosis, and a complete or partial response to colchicine. Despite the clinical similarities to familial Mediterranean fever (FMF), the underlying inflammatory mechanisms of SURF are not yet understood. We here analyzed the in vitro activation of the pyrin inflammasome in a cohort of SURF patients compared to FMF and PFAPA patients. Peripheral blood mononuclear cells (PBMC) were collected from SURF (both colchicine-treated and untreated), FMF, PFAPA patients, and healthy donors. PBMC were stimulated ex vivo with Clostridium difficile toxin A (TcdA) and a PKC inhibitor (UCN-01), in the presence or absence of colchicine. The assembly of the pyrin inflammasome was evaluated by measuring the presence of apoptosis-associated Speck-like protein containing caspase recruitment domain (ASC) specks in monocytes using flow cytometry. IL-1ß secretion was quantified using an ELISA assay. No differences in TcdA-induced activation of pyrin inflammasome were observed among FMF, PFAPA, and healthy donors. Untreated SURF patients showed a reduced response to TcdA, which was normalized after colchicine treatment. In contrast to FMF, SURF patients, similar to PFAPA patients and healthy donors, did not exhibit pyrin inflammasome activation in response to UCN-01-mediated pyrin dephosphorylation. These data demonstrate that in vitro functional analysis of pyrin inflammasome activation can differentiate SURF from FMF and PFAPA patients, suggesting the involvement of the pyrin inflammasome in the pathophysiology of SURF.

C5AR1-induced TLR1/2 pathway activation drives proliferation and metastasis in anaplastic thyroid cancer.

This study aimed to elucidate the role and mechanisms of Complement C5a receptor 1 (C5AR1) in driving the malignant progression of anaplastic thyroid carcinoma (ATC). C5AR1 expression was assessed in ATC tissues and cell lines. Functional assays evaluated the effects of C5AR1 knockdown on the malignant features of ATC cells. The interaction between C5AR1 and miR-335-5p was confirmed using a luciferase reporter assay and Fluorescence in situ hybridization, and the impact of C5AR1 knockdown on the Toll-like receptor (TLR) 1/2 signaling pathway was examined. In vivo studies evaluated the effects of C5AR1 modulation on tumor growth and metastasis. C5AR1 levels were elevated in ATC tumor samples and associated with poor survival in ATC patients. C5AR1 knockdown impeded ATC cell proliferation, migration, and invasion in vitro. MiR-335-5p was identified as an upstream regulator of C5AR1, which negatively modulates C5AR1 expression. C5AR1 knockdown diminished TLR1, TLR2, and myeloid differentiation primary response 88 (MyD88) levels, while C5AR1 overexpression activated this pathway. Blocking TLR1/2 signaling abrogated the oncogenic effects of C5AR1 overexpression. C5AR1 silencing inhibited tumor growth and lung metastasis of ATC cells in nude mice. C5AR1 contributes to ATC tumorigenesis and metastasis by activating the TLR1/2 pathway, and is negatively regulated by miR-335-5p. Targeting the miR-335-5p/C5AR1/TLR1/2 axis represents a potential therapeutic strategy for ATC.

Dedifferentiated and Undifferentiated Ovarian Carcinoma: An Aggressive and Molecularly Distinct Ovarian Tumor Characterized by Frequent SWI/SNF Complex Inactivation.

Dedifferentiated and undifferentiated ovarian carcinomas (DDOC/UDOC) are rare neoplasms defined by the presence of an undifferentiated carcinoma. In this study, we detailed the clinical, pathological, immunohistochemical, and molecular features of a series of DDOC/UDOC. We collected a multi-institutional cohort of 23 DDOC/UDOC and performed immunohistochemistry for core switch/sucrose nonfermentable (SWI/SNF) complex proteins (ARID1A, ARID1B, SMARCA4, and SMARCB1), mismatch repair (MMR) proteins, and p53. Array-based genome-wide DNA methylation and copy number variation analyses were performed on a subset of cases with comparison made to a previously reported cohort of undifferentiated endometrial carcinoma (UDEC), small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), and tubo-ovarian high-grade serous carcinoma (HGSC). The age of all 23 patients with DDOC/UDOC ranged between 22 and 71 years (with an average age of 50 years), and a majority of them presented with extraovarian disease (16/23). Clinical follow-up was available for 19 patients. Except for 2 patients, the remaining 17 patients died from disease, with rapid disease progression resulting in mortality within a year in stage II-IV settings (median disease-specific survival of 3 months). Eighteen of 22 cases with interpretable immunohistochemistry results showed loss of expression of core SWI/SNF protein(s) that are expected to result in SWI/SNF complex inactivation as 10 exhibited coloss of ARID1A and ARID1B, 7 loss of SMARCA4, and 1 loss of SMARCB1. Six of 23 cases were MMR-deficient. Two of 20 cases exhibited mutation-type p53 immunoreactivity. Methylation profiles showed coclustering of DDOC/UDOC with UDEC, which collectively were distinct from SCCOHT and HGSC. However, DDOC/UDOC showed an intermediate degree of copy number variation, which was slightly greater, compared with SCCOHT but much less compared with HGSC. Overall, DDOC/UDOC, like its endometrial counterpart, is highly aggressive and is characterized by frequent inactivation of core SWI/SNF complex proteins and MMR deficiency. Its molecular profile overlaps with UDEC while being distinct from SCCOHT and HGSC.

Undifferentiated Round Cell Sarcoma With CRTC1::SS18 Fusion: Expanding Clinicopathologic Features of a Rare Translocation Sarcoma With Prominent Desmoplastic Stroma.

Undifferentiated round cell sarcomas (URCS) represent a diverse group of tumors, including conventional Ewing sarcoma, round cell sarcoma with EWSR1/FUS-non-ETS fusions, CIC-rearranged sarcoma, and sarcoma with BCOR alterations. Since 2018, 3 cases of URCS with a novel CRTC1::SS18 gene fusion have been reported in the literature. Herein, we report 3 additional cases of CRTC1::SS18 sarcoma, thereby doubling the number of described cases and expanding the clinicopathologic features of this rare translocation sarcoma. Together with the previously reported cases, we show that the male-to-female ratio is 1:2 with a median age of 34 years (range, 12-42 years). Tumors occurred primarily in intramuscular locations involving the lower extremity. Histologically, all tumors contained uniform round-to-epithelioid cells with a moderate amount of eosinophilic cytoplasm growing in sheets and nests with prominent desmoplastic stroma reminiscent of desmoplastic small round cell tumor. Immunohistochemical results were nonspecific, demonstrating variable expression of CD99 (patchy), ALK, GATA3, and cyclin D1. RNA sequencing revealed CRTC1::SS18 gene fusions in all cases, involving exons 1 to 2 of CRTC1 (the 5' partner gene) on chromosome 19 and either exon 2 or exon 4 of SS18 (the 3' partner gene) on chromosome 18. The clinical course was variable. Although 1 previously reported case demonstrated aggressive behavior with a fatal outcome, 2 others had a relatively indolent course with gradual growth for 6 to 7 years prior to resection. Two cases developed metastatic disease, including 1 case with bilateral lung metastasis and 1 with locoregional spread to a lymph node. By analyzing the clinicopathologic features, we aimed to improve recognition of this rare translocation sarcoma to better understand its biologic potential, optimize patient management, and expand the current classification of URCS.

Proteomic Characterization of Undifferentiated Small Round Cell Sarcomas With EWSR1 and CIC::DUX4 Translocations Reveals Diverging Tumor Biology and Distinct Diagnostic Markers.

Undifferentiated small round cell sarcomas (USRS) of bone and soft tissue are a group of tumors with heterogenic genomic alterations sharing similar morphology. In the present study, we performed a comparative large-scale proteomic analysis of USRS (n = 42) with diverse genomic translocations including classic Ewing sarcomas with EWSR1::FLI1 fusions (n = 24) or EWSR1::ERG fusions (n = 4), sarcomas with an EWSR1 rearrangement (n = 2), CIC::DUX4 fusion (n = 8), as well as tumors classified as USRS with no genetic data available (n = 4). Proteins extracted from formalin-fixed, paraffin-embedded pretherapeutic biopsies were analyzed qualitatively and quantitatively using shotgun mass spectrometry (MS). More than 8000 protein groups could be quantified using data-independent acquisition. Unsupervised hierarchical cluster analysis based on proteomic data allowed stratification of the 42 cases into distinct groups reflecting the different molecular genotypes. Protein signatures that significantly correlated with the respective genomic translocations were identified and used to generate a heatmap of all 42 sarcomas with assignment of cases with unknown molecular genetic data to either the EWSR1- or CIC-rearranged groups. MS-based prediction of sarcoma subtypes was molecularly confirmed in 2 cases where next-generation sequencing was technically feasible. MS also detected proteins routinely used in the immunohistochemical approach for the differential diagnosis of USRS. BCL11B highly expressed in Ewing sarcomas, and BACH2 as well as ETS-1 highly expressed in CIC::DUX4-associated sarcomas, were among proteins identified by the present proteomic study, and were chosen for immunohistochemical confirmation of MS data in our study cohort. Differential expressions of these 3 markers in the 2 genetic groups were further validated in an independent cohort of n = 34 USRS. Finally, our proteomic results point toward diverging signaling pathways in the different USRS subgroups.

The utility of DNA methylation profiling in the diagnosis of un-, de- and trans-differentiated melanoma: a series of 11 cases.

AIMS: Melanomas are recognised for their remarkable morphological plasticity. Some tumours may lose conventional features and/or acquire non-melanocytic characteristics, referred to as undifferentiated, dedifferentiated and transdifferentiated melanoma. Despite this phenotypical variability, melanomas typically maintain their cancer driver aberrations, affecting genes such as BRAF, NRAS and NF1. Currently, little is known about whether the DNA methylation profile follows the loss or change of differentiation or is retained despite extensive morphological transformation. METHODS AND RESULTS: In this study we analysed 11 melanoma cases, comprising six males and five females, with a median age of 67 years, including five undifferentiated, four trans-differentiated and two de-differentiated melanomas. Undifferentiated and trans-differentiated tumours either arose in a patient with known melanoma and/or presented in the groin/axilla with molecular alterations consistent with melanoma. Cases with heterologous differentiation resembled chondrosarcoma, osteosarcoma, angiosarcoma and rhabdomyosarcoma both morphologically and immunohistochemically, while undifferentiated tumours resembled undifferentiated pleomorphic sarcoma. Methylome profiling was performed, and unsupervised clustering analysis revealed nine cases (five undifferentiated, three trans-differentiated and one de-differentiated) to cluster closely together with conventional melanomas from a reference set. Two cases clustered separately with a distinct group of conventional melanomas exhibiting H3K27me3 loss. CONCLUSIONS: Despite loss of differentiation and phenotypical plasticity, methylation patterns seem to be retained in undifferentiated, de-differentiated and trans-differentiated melanomas and represent useful diagnostic tools to enhance diagnostic precision in these diagnostically challenging cases.

Undifferentiated sarcomatoid carcinoma of the pancreas-a single-institution experience with 23 cases.

BACKGROUND: The clinical course and surgical outcomes of undifferentiated sarcomatoid carcinoma of the pancreas (USCP) remain poorly characterized owing to its rarity. This study aimed to describe the histology, clinicopathologic features, perioperative outcomes, and overall survival (OS) of 23 resected USCP patients. METHODS: We retrospectively described the histology, clinicopathologic features, perioperative outcomes and OS of patients who underwent pancreatectomy with a final diagnosis of USCP in a single institution. RESULTS: A total of 23 patients were included in this study. Twelve patients were male, the median age at diagnosis was 61.5 ± 13.0 years (range: 35-89). Patients with USCP had no specific symptoms and characteristic imaging findings. The R0 resection was achieved in 21 cases. The En bloc resection and reconstruction of mesenteric-portal axis was undertaken in 9 patients. There were no deaths attributed to perioperative complications in this study. The intraoperative tumor-draining lymph nodes (TDLNs) dissection was undergone in 14 patients. The 1-, 3- and 5-year survival rates were 43.5%, 4.8% and 4.8% in the whole study, the median survival was 9.0 months. Only 1 patient had survived more than 5 years and was still alive at last follow-up. The presence of distant metastasis (p = 0.004) and the presence of pathologically confirmed mesenteric-portal axis invasion (p = 0.007) was independently associated with poor OS. CONCLUSIONS: USCP was a rare subgroup of pancreatic malignancies with a bleak prognosis. To make a diagnose of USCP by imaging was quite difficult because of the absence of specific manifestations. Accurate diagnosis depended on pathological biopsy, and the IHC profile of USCP was mainly characterized by co-expression of epithelial and mesenchymal markers. A large proportion of patients have an early demise, especially for patients with distant metastasis and pathologically confirmed mesenteric-portal axis invasion. Long-term survival after radical resection of USCPs remains rare.

Preclinical 3D model screening reveals digoxin as an effective therapy for a rare and aggressive type of endometrial cancer.

OBJECTIVE: Dedifferentiated endometrial carcinoma (DDEC) characterized by SWItch/Sucrose Non-Fermentable (SWI/SNF) complex inactivation is a highly aggressive type of endometrial cancer without effective systemic therapy options. Its uncommon nature and aggressive disease trajectory pose significant challenges for therapeutic progress. To address this obstacle, we focused on developing preclinical models tailored to this tumor type and established patient tumor-derived three-dimensional (3D) spheroid models of DDEC. METHODS: High-throughput drug repurposing screens were performed on in vitro 3D spheroid models of DDEC cell lines (SMARCA4-inactivated DDEC-1 and ARID1A/ARID1B co-inactivated DDEC-2). The dose-response relationships of the identified candidate drugs were evaluated in vitro, followed by in vivo evaluation using xenograft models of DDEC-1 and DDEC-2. RESULTS: Drug screen in 3D models identified multiple cardiac glycosides including digoxin and digitoxin as candidate drugs in both DDEC-1 and DDEC-2. Subsequent in vitro dose-response analyses confirmed the inhibitory activity of digoxin and digitoxin with both drugs showing lower IC50 in DDEC cells compared to non-DDEC endometrial cancer cells. In in vivo xenograft models, digoxin significantly suppressed the growth of DDEC tumors at clinically relevant serum concentrations. CONCLUSION: Using biologically precise preclinical models of DDEC derived from patient tumor samples, our study identified digoxin as an effective drug in suppressing DDEC tumor growth. These findings provide compelling preclinical evidence for the use of digoxin as systemic therapy for SWI/SNF-inactivated DDEC, which may also be applicable to other SWI/SNF-inactivated tumor types.

Trends in Mortality for Anaplastic Thyroid Cancer: Have We Made Progress?

INTRODUCTION: Anaplastic thyroid cancer (ATC) has one of the highest mortality rates of all human malignancies, accounting for two-thirds of all thyroid cancer deaths. Despite multimodal treatment, ATC still has a reported median survival period of 6 mo. Recent single-center studies have reported improved survival with the approval of new treatments for ATC. In this study, we sought to investigate whether the approval of new treatments and use of multimodal treatments was associated with reduced risk of mortality over time nationally. METHODS: Eight hundred and seventy four patients in the National Cancer Institute's Surveillance, Epidemiology, and End Results database that were diagnosed with ATC from 1990 to 2020 were included in this study. Cox proportional hazards models were used to assess the change in 2-y survival over time and to identify characteristics associated with survival. Overall survival (OS) and cancer specific survival (CSS) were both evaluated. RESULTS: The OS within 2 y of diagnosis was 14% and the CSS was 19%. For every 3-y increase in diagnosis year from 1990 to 2020, there was no significant change in the CSS (adjusted hazard ratio [95% confidence interval]: 0.98 [0.94, 1.01]). Patients who received treatment (surgery, chemotherapy, and/or radiation) had an increased CSS (adjusted hazard ratio [95% confidence interval]: 0.42 [0.32, 0.55]). CONCLUSIONS: We observed no significant change in OS or CSS after adjusting for confounders by year of diagnosis. Though receiving treatment was associated with increased CSS, more effective treatments are needed in the future to increase survival time in patients with ATC.

Natural history of undifferentiated pleomorphic sarcoma: Experience from the US Sarcoma Collaborative.

BACKGROUND: Undifferentiated pleomorphic sarcoma (UPS) is a relatively rare but aggressive neoplasm. We sought to utilize a multi-institutional US cohort of sarcoma patients to examine predictors of survival and recurrence patterns after resection of UPS. METHODS: From 2000 to 2016, patients with primary UPS undergoing curative-intent surgical resection at seven academic institutions were retrospectively reviewed. Epidemiologic and clinicopathologic factors were reviewed by site of origin. Overall survival (OS), recurrence-free survival (RFS), time-to-locoregional (TTLR), time-to-distant recurrence (TTDR), and patterns of recurrence were analyzed. RESULTS: Of the 534 UPS patients identified, 53% were female, with a median age of 60 and median tumor size of 8.5 cm. The median OS, RFS, TTLR, and TTDR for the entire cohort were 109, 49, 86, and 46 months, respectively. There were no differences in these survival outcomes between extremity and truncal UPS. Compared with truncal, extremity UPS were more commonly amenable to R0 resection (87% vs. 75%, p = 0.017) and less commonly associated with lymph node metastasis (1% vs. 6%, p = 0.031). R0 resection and radiation treatment, but not site of origin (extremity vs. trunk) were independent predictors of OS and RFS. TTLR recurrence was shorter for UPS resected with a positive margin and for tumors not treated with radiation. CONCLUSION: For patients with resected extremity and truncal UPS, tumor size >5 cm and positive resection margin are associated with worse survival OS and RFS, irrespectively the site of origin. R0 surgical resection and radiation treatment may help improve these survival outcomes.

Management of undifferentiated embryonal sarcoma of the liver: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: Undifferentiated embryonal sarcoma of the liver (UESL) is a rare tumor for which there are few evidence-based guidelines. The aim of this study was to define current management strategies and outcomes for these patients using a multi-institutional dataset curated by the Pediatric Surgical Oncology Research Collaborative. METHODS: Data were collected retrospectively for patients with UESL treated across 17 children's hospitals in North America from 1989 to 2019. Factors analyzed included patient and tumor characteristics, PRETEXT group, operative details, and neoadjuvant/adjuvant regimens. Event-free and overall survival (EFS, OS) were the primary and secondary outcomes, respectively. RESULTS: Seventy-eight patients were identified with a median age of 9.9 years [interquartile range [IQR): 7-12]. Twenty-seven patients underwent resection at diagnosis, and 47 patients underwent delayed resection, including eight liver transplants. Neoadjuvant chemotherapy led to a median change in maximum tumor diameter of 1.6 cm [IQR: 0.0-4.4] and greater than 90% tumor necrosis in 79% of the patients undergoing delayed resection. R0 resections were accomplished in 63 patients (81%). Univariate analysis found that metastatic disease impacted OS, and completeness of resection impacted both EFS and OS, while multivariate analysis revealed that R0 resection was associated with decreased expected hazards of experiencing an event [hazard ratio (HR): 0.14, 95% confidence interval (CI): 0.04-0.6]. At a median follow-up of 4 years [IQR: 2-8], the EFS was 70.0% [95% CI: 60%-82%] and OS was 83% [95% CI: 75%-93%]. CONCLUSION: Complete resection is associated with improved survival for patients with UESL. Neoadjuvant chemotherapy causes minimal radiographic response, but significant tumor necrosis.

Predictive significance of pretreatment 18F-FDG PET volumetric parameters on survival outcomes in pediatric patients with locally advanced undifferentiated nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a rare pediatric cancer. Most children are first diagnosed with advanced locoregional disease. Identification of patients at higher risk of treatment failure is crucial as they may benefit from more aggressive initial treatment approaches. 18Fluorine-labeled fluoro-2-deoxyglucose positron emission tomography (18F-FDG PET) has shown promise as a prognostic tool for predicting outcomes. METHODS: Retrospective study of pediatric patients with locally advanced undifferentiated NPC who underwent 18F-FDG PET/CT prior to intial treatment. Predictive significance of metabolic PET parameters on survival outcomes were estimated. RESULTS: Thirty-two children were included, age range was 7.1-18 years at the time of diagnosis. The median follow-up duration was 46.1 months. Three patients (9.4%) were classified as AJCC stage IIb, 13 patients (40.6%) as stage IIIa, eight patients (25%) as stage IIIb, and eight patients (25%) as stage IVa. Our findings revealed that high whole-body metabolic tumor volume at the threshold of hepatic reference SUVmean (WB-MTV-HR) (>135 mL) was associated with significantly lower event-free survival (EFS) compared to the low WB-MTV-HR group (≤135 mL) (3-year EFS: 50% ± 18% vs. 82% ± 8%; p = .015). Additionally, the 3-year overall survival (OS) rates differed significantly between the high whole-body metabolic tumor volume at the threshold of an SUV of 2.5 isocontour (WB-MTV-2.5) group (MTV >74 mL) and the low WB-MTV-2.5 group (MTV ≤74 mL) (63% ± 18% vs. 100%; p = .021). CONCLUSION: Our study suggests that WB-MTV parameters could serve as significant prognostic factors for disease progression in pediatric patients with locally advanced undifferentiated NPC. However, further prospective studies with larger sample sizes are needed to validate these findings.

Expanding the Spectrum of Sarcoma with an Internal Tandem Duplication of BCOR: A Non-Pediatric Nasosinusal Case.

INTRODUCTION: Undifferentiated small round-cell sarcomas with BCL6 corepressor (BCOR) alterations, such as an internal tandem duplication (ITD) within exon 15, are typically described as a pediatric group of Ewing-like small round-cell sarcomas. CASE PRESENTATION: In contrast to this notion, we report the case of a 71-year-old woman with a nasosinusal sarcoma featuring a BCOR ITD. To the best of our knowledge, this presence had not been previously documented in a sarcoma of the nasal and sinus cavities in an elderly patient. The identified duplication shares a similar minimal critical region as described in clear-cell sarcomas of the kidney in children. This alteration, located within the PCGF1 binding domain, is believed to disrupt the activity of PRC1.1. CONCLUSION: This case underscores the need for in-depth research into the molecular biology of these rare tumors and explores potential alternative treatment options. The patient achieved remission after two cycles of doxorubicin and cyclophosphamide chemotherapy, highlighting the promise of potential therapeutic options for BCOR ITD sarcomas.

SMARCA4-deficient undifferentiated gastric carcinoma: a case series and literature review.

Undifferentiated gastric carcinoma, characterized by anaplastic cells lacking distinct features of cytological or architectural differentiation, poses diagnostic and therapeutic challenges. Recent studies have suggested an association between this carcinoma and deficiencies in the SWI/SNF complex, particularly mutations in subunits such as SMARCA4. We herein report six cases of SMARCA4-deficient undifferentiated gastric carcinoma with molecular findings, highlighting the rarity and diagnostic pitfalls of this malignancy. Predominantly occurring in males over 50 years, these cases presented with nonspecific symptoms and were often diagnosed at an advanced stage. Histologically, the tumors exhibited a sheet-like growth pattern, reduced or absent epithelial markers, and loss of BRG-1 expression, with molecular analysis confirming SMARCA4 gene mutations. The response to conventional chemotherapy was poor, underscoring the importance of complete surgical resection and the development of alternative treatment modalities.

Identification of maximal tumor size associated with negligible lymph node metastasis for endoscopic submucosal dissection of undifferentiated-type early gastric cancer.

BACKGROUND AND AIMS: When treating undifferentiated-type early gastric cancer (UD-EGC) that is limited to the mucosa (clinically T1a), endoscopic submucosal dissection (ESD) can be considered if the tumor is 2 cm or less and is not ulcerated. However, there is insufficient evidence to determine the relationships between tumor size and oncological safety of ESD in UD-EGC. METHODS: The pathology reports of Korean patients who were diagnosed with UD-EGC (n = 5286) were retrospectively reviewed. The cumulative incidence of lymph node metastasis (LNM) according to tumor size was evaluated in subgroups. The tumor-size cut-off was identified as the upper limit of the 95% confidence interval (CI) of cumulative LNM incidence that did not exceed 1.0%. RESULTS: We identified 1516 patients with non-ulcerated T1a tumors ≤2 cm in size. Among patients without lymphatic invasion, 1.5% (95% CI 0.91-2.16%) had LNM. In patients with poorly differentiated tubular adenocarcinoma (PD), LNM increased from 0 to 0.74% based on a tumor size of 1.0 cm. Regardless of tumor size, smaller percentages of undifferentiated-type (UD) and poorly cohesive carcinoma (PCC) patients experienced LNM than did those with PD. In non-ulcerated mucosal cancer without lymphatic invasion and tumor size ≤0.9 cm, no LNM was observed in patients with UD (95% CI 0-0.53%), PCC (95% CI 0-0.59%), or PD (95% CI 0-0.86%) histologic type. CONCLUSION: In patients diagnosed with non-ulcerated T1a UD-EGC, ESD can be performed if the tumor size is 0.9 cm or less, regardless of histologic type.

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.