An EWSR1-CREB3L1 Fusion Gene in Extraskeletal Undifferentiated Round Cell Sarcoma Expands the Spectrum of Genetic Landscape in the "Ewing-Like" Undifferentiated Round Cell Sarcomas

Case Report: Colon malignant tumor caused by retroperitoneal small round cell undifferentiated sarcoma

Small round cell undifferentiated sarcoma is a rare and highly invasive group of malignant bone and soft tissue tumors, often associated with a high misdiagnosis rate. The patient in this case was a 34-year-old male who presented with a two-month history of abdominal pain that worsened over the past two weeks. Elevated levels of tumor markers CA19-9 and CA72-4 were observed. Imaging revealed a substantial, well-vascularized mass in the lower left abdomen, located in the posterior abdominal cavity, invading the descending colon and the root of the small mesentery, and infiltrating the serous layer. The lesion was extensively resected without any postoperative complications. Microscopic examination indicated a combination of mucinous adenocarcinoma (approximately 30%) and small round cell undifferentiated sarcoma (approximately 70%). The patient was followed up for six months, and one month after surgery, a recurrence of the tumor was observed in the left paracolonic sulcus area, with metastases to the abdominal wall, peritoneum, and medial iliac muscles. Chemotherapy and targeted therapy were administered, and the patient currently survives with the presence of tumors. Small round cell undifferentiated sarcoma is an uncommon and highly invasive tumor, and clinical surgeons need to raise their awareness and realize to the maximum extent possible that this disease can be described through a multi-modal combination of immunohistochemistry and genetic test to improve diagnostic accuracy and reduce missed diagnoses. Further research in the field of biology is necessary to explore targeted drugs specifically suitable for this disease.

Adamantinoma-like ewing sarcoma arising in the pancreatic tail: a case report of a rare entity and review of the literature

ALES is a rare subtype that demonstrates the EWSR1-FLI1 translocation characteristic of ES and demonstrates complex epithelial differentiation including diffuse cytokeratin and p40 expression. It has predominantly recognized in the head and neck and is common in middle-aged population. This case is the first case of ALES reported in the pancreatic tail, sharing some morphological characteristics with ALES in the head and neck, including monotonous cytology, infiltrative growth pattern, and complex epithelioid differentiation, but ALES in the head and neck often has high-grade histological features (e.g., necrosis, high mitotic rate, etc.), and sudden keratinization can also occur, but these features were not reflected in this primary pancreatic tail ALES. Although ALES arising in the pancreatic tail and in the head and neck sites share the immunohistochemical and molecular profile, our case can provide new ideas in differential diagnosis of ALES arising in pancreatic tail and promote increased recognition and understanding of ALES.

Prognostic Nomogram of Osteocarcinoma after Surgical Treatment

Purpose

This study aimed to establish a valid prognostic nomogram for osteocarcinoma after surgical management.

Methods

Based on the SEER database, we retrieved the clinical variables of patients confirmed to have osteocarcinoma between 1975 and 2016. Then, we performed univariate and multivariate analyses and constructed a nomogram of overall survival.

Results

Multivariate analysis of the primary cohort revealed that the independent factors for survival were age, grade, pathologic stage, T stage, and surgery performed. All these factors were showed by the nomogram. The correction curve of survival probability showed that the prediction results of nomogram well agreed with the actual observation results. The C index of the nomogram used to predict survival was 0.82; the AUC of 1-year, 3-year, and 5-year survival rates in the training cohort were 0.9, 0.819, and 0.80631, respectively, indicating that the model was accurate and reliable; whether the operation was performed or not; T stage; grade; and age were the main factors affecting the survival of patients. The AUC of the validation cohort for 1 year, 3 years, and 5 years were 0.8, 0.831, and 0.80023, respectively.

Conclusion

The proposed nomogram can more accurately predict the prognosis of patients with osteocarcinoma after surgical management. This could be a potential method that services clinical work.

Pan-cancer analysis of CREB3L1 as biomarker in the prediction of prognosis and immunotherapeutic efficacy

Background: CAMP response element binding protein 3-like 1 (CREB3L1) has been indicated as a critical biomarker and can modulate multifaced behaviors of tumor cells in diverse cancers. However, a systematic assessment of CREB3L1 in pan-cancer is of absence, and the predictive value of CREB3L1 in cancer prognosis, the tumor immune microenvironment and the efficacy of immunotherapy remains unexplored.

Methods: CREB3L1 expression in 33 different cancer types was investigated using RNAseq data from The Cancer Genome Atlas (TCGA) database. The characteristics of CREB3L1 alternations were illustrated in cBioPortal database. The prognostic and clinicopathological value of CREB3L1 was analyzed through clinical data downloaded from the TCGA database. The potential role of CREB3L1 in the tumor immune microenvironment was illustrated by utilizing CIBERSORT and ESTIMATE algorithms, and TISIDB online database. The associations between CREB3L1 expression and tumor mutation burden (TMB), and microsatellite instability (MSI) were assessed by spearman’s rank correlation coefficient. Furthermore, Gene Set Enrichment Analysis (GSEA) was conducted to explore the potential biological functions and downstream pathways of CREB3L1 in different human cancers. The correlations of CREB3L1 expression with PD-1/PD-L1 inhibitors efficacy and drug sensitivity were also investigated.

Results: The expression of CREB3L1 was abnormally high or low in several different cancer types, and was also strictly associated with the prognosis of cancer patients. CREB3L1 expression levels have a strong relationship with infiltrating immune cells, including regulatory T cells, CD8+ T cells, macrophages, B naïve cells, dendritic cells and mast cells. CREB3L1 expression was also correlated with the expression of multiple immune-related biomolecules, TMB, and MSI in several cancers. Moreover, CREB3L1 had promising applications in predicting the immunotherapeutic benefits and drug sensitivity in cancer management.

Conclusions: Our results highlight the value of CREB3L1 as a predictive biomarker for the prognosis and immunotherapy efficacy in multiple cancers, and CREB3L1 seems to play key roles in the tumor immune microenvironment, suggesting the role of CREB3L1 as a promising biomarker for predicting the prognosis and immune-related signatures in diverse cancers.

Detection of sarcoma fusions by a next-generation sequencing based-ligation-dependent multiplex RT-PCR assay

Morphological, immunohistochemical, and molecular methods often need to be combined for accurate diagnosis and optimal clinical management of sarcomas. Here, we have developed, a new molecular diagnostic assay, for the detection of gene fusions in sarcomas. This targeted multiplexed next-generation sequencing (NGS)-based method utilizes ligation dependent reverse-transcriptase polymerase chain reaction (LD-RT-PCR-NGS) to detect oncogenic fusion transcripts involving 137 genes, leading to 139 gene fusions known to be recurrently rearranged in soft-tissue and bone tumors. 158 bone and soft-tissue tumors with previously identified fusion genes by fluorescent in situ hybridization (FISH) or RT-PCR were selected to test the specificity and the sensitivity of this assay. RNA were extracted from formalin-fixed paraffin-embedded (n = 143) or frozen (n = 15) material (specimen; n = 42 or core needle biopsies; n = 116). Tested tumors encompassed 23 major translocation-related sarcomas types, including Ewing and Ewing-like sarcomas, rhabdomyosarcomas, desmoplastic small round-cell tumors, clear-cell sarcomas, infantile fibrosarcomas, endometrial stromal sarcomas, epithelioid hemangioendotheliomas, alveolar soft-part sarcomas, biphenotypic sinonasal sarcomas, extraskeletal myxoid chondrosarcomas, myxoid/round-cell liposarcomas, dermatofibrosarcomas protuberans and solitary fibrous tumors. In-frame fusion transcripts were detected in 98.1% of cases (155/158). Gene fusion assay results correlated with conventional techniques (FISH and RT-PCR) in 155/158 tumors (98.1%). These data demonstrate that this assay is a rapid, robust, highly sensitive, and multiplexed targeted RNA sequencing assay for the detection of recurrent gene fusions on RNA extracted from routine clinical specimens of sarcomas (formalin-fixed paraffin-embedded or frozen). It facilitates the precise diagnosis and identification of tumors with potential targetable fusions. In addition, this assay can be easily customized to cover new fusions.

Loss of histone H3 trimethylation on lysine 27 and nuclear expression of transducin-like enhancer 1 in primary intracranial sarcoma, DICER1-mutant

AIMS

Primary intracranial sarcoma, DICER1-mutant is a recently described central nervous system tumour with specific genomic and DNA-methylation profiles. Although some of its histological features (focal spindle-cell morphology, intracytoplasmic eosinophilic granules, and focal heterologous differentiation) are common across most reported cases, the presence of significant histological variability and the lack of differentiation pose diagnostic challenges. We aim to further define the immunoprofile of this tumor.

METHODS AND RESULTS

We reviewed the clinical history and performed immunohistochemistry for glial fibrillary acidic protein, oligodendrocyte transcription factor 2, SOX2, SOX10, S100, histone H3 trimethylated on lysine 27 (H3K27me3), desmin, myogenin, CD99, epithelial membrane antigen (EMA) and transducin-like enhancer of split 1 (TLE1) on six primary intracranial sarcomas, DICER1-mutant, with appropriate controls. Targeted exome sequencing was performed on all cases. The sarcomas showed diffuse (n = 4), mosaic (n = 1) or minimal (≤5%, n = 1) loss of H3K27 trimethylation and nuclear TLE1 expression (n = 6). Four had immunohistochemical evidence of myogenic differentiation. SOX2, SOX10, S100 and EMA were negative; CD99 expression ranged from focal cytoplasmic (n = 4) to crisp diffuse membranous (n = 2). One tumour had focal cartilaginous differentiation. Similar immunohistochemical findings were observed in a pleuropulmonary blastoma (albeit with focal TLE1 expression), a DICER1-related pineoblastoma, and an embryonal tumour with a multilayered rosette-like DICER1-related cerebellar tumour. Targeted exome sequencing confirmed the presence of pathogenic biallelic DICER1 mutations in all tumours included in this study.

CONCLUSION

We conclude that H3K27me3 and TLE1 immunostains, when utilised in combination, can be helpful diagnostic markers for primary intracranial sarcoma, DICER1-mutant.