CIC-fused sarcomas represent an emerging family of tumors, for long connected to the Ewing family group of tumors, but underlined by distinct CIC fusions with different partners. 3′ Fusion partners ...include DUX4, FOXO4, and, as recently emphasized, NUTM1. In this study, we report the clinicopathologic and molecular features of a series of 6 CIC-NUTM1 sarcomas. Mean age at diagnosis was 6 years (2 to 27 y), and 4 patients were male individuals. Primary tumors were located in the central nervous system (n=3), paravertebral soft tissue and epidural spaces (n=1, each), and lung (n=1). Median overall survival was 17.5 months (7 to 37 mo), and all but one patient died of disease. All tumors displayed classic features of CIC-DUX4 sarcomas with round cell to epithelioid microscopic appearance. Most tumors expressed ETV4 and NUTM1 (n=5/6 and 6/6, respectively), whereas WT1cter was positive in only 2 cases. All tested tumors were positive for break-apart fluorescence in situ hybridization for CIC and NUTM1. Apart from CIC or NUTM1 genomic breakpoints, no other recurrent copy number alteration was seen on genomic profiles. Fusion transcripts were identified by RNA-sequencing on either formalin-fixed paraffin-embedded or frozen material. CIC and NUTM1 breakpoints were located between exons 16 and 20 and exons 2 and 5, respectively. Altogether, CIC-NUTM1 sarcomas represent a new molecular variant of CIC-fused sarcomas with a predilection for the central nervous system and younger pediatric population. Its phenotype may be confused with NUT carcinomas.
Deep penetrating nevus (DPN) is characterized by enlarged, pigmented melanocytes that extend through the dermis. DPN can be difficult to distinguish from melanoma but rarely displays aggressive ...biological behavior. Here, we identify a combination of mutations of the β-catenin and mitogen-activated protein kinase pathways as characteristic of DPN. Mutations of the β-catenin pathway change the phenotype of a common nevus with BRAF mutation into that of DPN, with increased pigmentation, cell volume and nuclear cyclin D1 levels. Our results suggest that constitutive β-catenin pathway activation promotes tumorigenesis by overriding dependencies on the microenvironment that constrain proliferation of common nevi. In melanoma that arose from DPN we find additional oncogenic alterations. We identify DPN as an intermediate stage in the step-wise progression from nevus to melanoma. In summary, we delineate specific genetic alterations and their sequential order, information that can assist in the diagnostic classification and grading of these distinctive neoplasms.Deep penetrating nevi (DPN) are unusual melanocytic neoplasms with unknown genetic drivers. Here the authors show that majority of DPN harbor activating mutations in the β-catenin and the MAP-kinase pathways; this characteristic can help in the classification and grading of these distinctive neoplasms.
Rhabdomyosarcoma (RMS) encompasses a heterogenous collection of tumors in which new groups have recently been identified that improved the World Health Organization (WHO) classification. While ...performing RNA-sequencing in our routine practice, we identified 3 cases of well-differentiated RMS harboring new fusion genes. We also analyzed these tumors through array-comparative genomic hybridization. Clinically, these tumors were deep paraspinal tumors, occurring in neo-nat and young children. The patients underwent resection and adjuvant therapy. At the time of last follow-up (ranging from 12 to 108 mo), they were alive without disease. Histologically, these tumors consisted of well-differentiated rhabdomyoblastic proliferations with nuclear atypia, infiltrative borders, and a specific growth pattern. These tumors harbored new fusion genes involving SRF and either FOXO1 or NCOA1. We compared the expression profiles of these 3 tumors to the expression data of a series of 33 skeletal muscle tumors including embryonal RMSs, alveolar rhandomyosarcomas, RMSs with VGLL2 fusions, RMSs with the myoD1 mutation, EWSR1/FUS-TFCP2 epithelioid and spindle cell RMSs of the bone, and rhabdomyomas with PTCH1 loss. According to clustering analyses, the 3 SRF-fused tumors formed a distinct group with a specific expression profile different from that of the other types of skeletal muscle tumors. Array-comparative genomic hybridization showed a recurrent gain of chromosome 11. These 3 tumors define a new group of RMS associated with a fusion of the SRF gene. FOXO1 rearrangements, usually used to confirm the diagnosis of alveolar RMS and identify poor-outcome RMSs, were identified in a nonalveolar RMS for the first time.
Cutaneous sweat gland tumors are a subset of adnexal neoplasms that derive or differentiate into the sweat apparatus. Their great diversity, rarity, and complex terminology make their pathological ...diagnosis challenging. Recent findings have revealed a wide spectrum of oncogenic drivers, several of which are of diagnostic interest for pathologists. Most of these molecular alterations are represented by gene fusions, which are shared with other homologous neoplasms occurring in organs containing exocrine glands, such as salivary and breast glands, which show similarities to the sweat apparatus. This review aims to provide a synthesis of the most recent immunohistochemical and molecular markers used for the diagnosis of sweat gland tumors and to highlight their relationship with similar tumors in other organs. It will cover adenoid cystic carcinoma (
,
and
fusion), cutaneous mixed tumor (
fusion), cylindroma and spiradenoma and their carcinomas thereof (NF-κB activation through
inactivation or
hotspot mutation), hidradenoma and hidradenocarcinoma (
fusion), myoepithelioma (
and
fusion), poroma and porocarcinoma (
,
and
fusion), secretory carcinoma (
,
fusion), tubular adenoma and syringo-cystadenoma papilliferum (
and
activating mutations). Sweat gland tumors for which there are no known molecular abnormalities will also be briefly discussed, as well as potential future developments.
Paraneoplastic cerebellar degenerations with anti-Yo antibodies (Yo-PCD) are rare syndromes caused by an auto-immune response against neuronal antigens (Ags) expressed by tumor cells. However, the ...mechanisms responsible for such immune tolerance breakdown are unknown. We characterized 26 ovarian carcinomas associated with Yo-PCD for their tumor immune contexture and genetic status of the 2 onconeural Yo-Ags,
CDR2
and
CDR2L
. Yo-PCD tumors differed from the 116 control tumors by more abundant T and B cells infiltration occasionally organized in tertiary lymphoid structures harboring CDR2L protein deposits. Immune cells are mainly in the vicinity of apoptotic tumor cells, revealing tumor immune attack. Moreover, contrary to un-selected ovarian carcinomas, 65% of our Yo-PCD tumors presented at least one somatic mutation in Yo-Ags, with a predominance of missense mutations. Recurrent gains of the
CDR2L
gene with tumor protein overexpression were also present in 59% of Yo-PCD patients. Overall, each Yo-PCD ovarian carcinomas carried at least one genetic alteration of Yo-Ags. These data demonstrate an association between massive infiltration of Yo-PCD tumors by activated immune effector cells and recurrent gains and/or mutations in autoantigen-encoding genes, suggesting that genetic alterations in tumor cells trigger immune tolerance breakdown and initiation of the auto-immune disease.
Micro‐RNAs (miRNA) are currently used as cancer biomarkers for hematological cancers and solid tumors. Osteosarcoma is the first primary malignant bone tumor, characterized by a complex genetic and ...resistance to conventional treatments. For this latter property, the median survival has not been improved since 1990 despite preoperative administration of chemotherapeutic agents. The prediction of tumor response before chemotherapy treatment would constitute a major progress for this pathology. We assessed in this study if miRNA profiling could surpass the current limitations for osteosarcoma diagnosis. We measured the miRNA expression in different osteosarcoma samples: (i) 27 osteosarcoma paraffin‐embedded tumors from patients, (ii) human osteosarcoma cell lines, and (iii) tumors from a syngeneic rat osteosarcoma model, recapitulating human osteosarcoma. miRNA profiles were determined using microfluidic cards performing high‐throughput TaqMan®‐based PCR assays, called TaqMan® Low Density Arrays. Osteosarcoma of rat and human origins showed a miRNA signature, which could discriminate good from bad responders. In particular, we identified five discriminating miRNAs (miR‐92a, miR‐99b, miR‐132, miR‐193a‐5p and miR‐422a) in patient tumors, which could be easily transferable to diagnosis. These discriminating miRNAs, as well as those identified in rat, targeted the TGFβ, the Wnt and the MAP kinase pathways. These results indicate that our platform constitutes a potent diagnostic tool to predict tumor sensitivity to a drug in attempt to better adapt treatment to tumor biological specificities and also to identify new potential therapeutic strategies.
This article focuses on families of round cell sarcomas other than classical Ewing sarcomas. Until recently, these tumors were referred to as so-called Ewing-like tumors, as they morphologically ...resemble Ewing sarcomas but are negative for canonical fusion transcripts of Ewing sarcomas involving gene members of the ETS family of transcription factors. Clinicopathologic and molecular evidence has dramatically influenced the diagnostic approach of these tumors in recent years. Molecular data that support these sarcoma subtypes are biologically distinct from those of Ewing sarcomas, thereby advocating discarding the all-embracing and confusing terminology of "Ewing-like tumors."
Background
While great advances in clinical and pathological description of tenosynovial giant cell tumors (TGCT) have been made, TGCT molecular heterogeneity represents an ongoing challenge. The ...canonical oncogenic fusion
CSF1::COL6A3
is not systematically observed, suggesting that other oncogenic mechanisms are involved in tumorigenesis. This study aims to explore by RNA sequencing a retrospective series of tumors diagnosed as TGCT, in order to provide a better description of their molecular landscape and to correlate molecular features with clinical data.
Methods
We analyzed clinicopathological data and performed whole-exome RNA sequencing on 41 TGCT samples.
Results
RNAseq analysis showed significant higher CSF1 and CSF1-R expression than a control panel of 2642 solid tumors. RNA sequencing revealed fusion transcripts in 14 patients including 6 not involving CSF1 and some previously unreported fusions. Unsupervised clustering on the expression profiles issued from this series suggested two distinct subgroups: one composed of various molecular subtypes including
CSF1
and
FN1
rearranged samples and one composed of four tumors harboring an
HMGA2::NCOR2
fusion, suggesting distinct tumor entities. Overall, 15 patients received at least one systemic anti-CSF1R treatment and clinical improvement was observed in 11 patients, including patients from both clusters.
Discussion
This study reported molecular heterogeneity in TGCT, contrasting with the clinical and pathological homogeneity and the ubiquitous high CSF1 and CSF1R expression levels. Whether molecular diversity may impact the efficacy of systemic treatments needs to be further investigated.
A series of 42 patient tumors diagnosed as endometrial stromal sarcoma (ESS) based on the morphology but negative for JAZF1 and/or YWHAE rearrangement in FISH was analyzed by RNA-sequencing. A ...chromosomal rearrangement was identified in 31 (74%) of the cases and a missense mutation in known oncogenes/tumor suppressor genes in 11 (26%). Cluster analyses on the expression profiles from this series together with a control cohort composed of five samples of low grade ESS harboring a JAZF1-SUZ12 fusion, one high grade ESS harboring a BCOR-ITD, two uterine tumors resembling ovarian sex cord tumors, two samples each of uterine leiomyoma and leiomyosarcomas and a series of BCOR-rearranged family of tumor (n = 8) indicated that tumors could be gather in three distinct subgroups: one mainly composed of BCOR-rearranged samples that contained seven ESS samples, one mainly composed of JAZF1-fused ESS (n = 15) and the last composed of various molecular subtypes (n = 19). These three subgroups display different gene signatures, different in silico cell cycle scores and very different clinical presentations, natural history and survival (log-rank test, p = 0.004). While YWHAE-NUTM2 fusion genes may be present in both high and low grade ESS, the high-grade presents with additional BCOR or BCORL1 gene mutations. RNAseq brings clinically relevant molecular classification, enabling the reclassification of diseases and the guidance of therapeutic strategy.
Background
In certain rare undifferentiated small round cell sarcomas new specific molecular CIC‐DUX4/other partner, BCOR‐CCNB3/other partner, YWHAE fusions, or BCOR‐ITD (internal tandem duplication) ...were identified. These new “CIC fused” (CIC‐fused/ATXN1::NUTM1) and “BCOR rearranged” (BCOR fused/ITD/ YWHAE) soft tissue sarcomas (STS) are not well described.
Methods
Multi‐institutional European retrospective analysis of young patients (0–24 years) with CIC‐fused and BCOR rearranged STS.
Results
Overall, out of the 60 patients selected, the fusion status was CIC‐fused (n = 29), ATXN1::NUTM1 (n = 2), BCOR::CCNB3 (n = 18), BCOR‐ITD (n = 7), and YWHAE (n = 3), MAML::BCOR STS (n = 1). The main primaries were abdomen‐pelvic (n = 23) and limbs (n = 18). Median age was 14 years (0.9–23.8) and 0.9 (0.1–19.1) for CIC‐fused and BCOR‐rearranged groups, respectively (n = 29; p < 0.001). IRS stages were I (n = 3), II (n = 7), III (n = 35), and IV (n = 15). Overall, 42 patients had large tumors (>5 cm) but only six had lymph node involvement. Patients received mainly chemotherapy (n = 57), local surgery (n = 50), and/or radiotherapy (n = 34). After a median follow‐up of 47.1 months (range, 3.4–230), 33 (52%) patients had an event and 23 patients died. Three‐year event‐free survivals were 44.0% (95% CI 28.7–67.5) and 41.2% (95% CI 25.4–67.0) for CIC and BCOR groups (p = 0.97), respectively. Three‐year overall survivals were 46.3% (95% CI 29.6–72.4) and 67.1% (95% CI 50.4–89.3; p = 0.24), respectively.
Conclusions
Pediatric patients often present with large tumors and metastatic disease, especially CIC sarcomas. Overall outcome is dismal. New treatment options are needed.
CIC, BCOR, and YWHAE rearranged soft tissue sarcomas are poorly characterized.
Analysis of 60 young patients with these very rare sarcomas.
Overall outcome is dismal and new therapies are warranted.
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