A nationwide analysis of desmoplastic small round cell tumor

Pediatric Soft Tissue Sarcoma in Limb-Girdle Muscular Dystrophy: Molecular Findings and Clinical Implications

BACKGROUND Limb-girdle muscular dystrophy recessive 1 (LGMDR1) is an autosomal recessive degenerative muscle disorder characterized by progressive muscular weakness caused by pathogenic variants in the CAPN3 gene. Desmoplastic small round cell tumors (DSRCT) are ultra-rare and aggressive soft tissue sarcomas usually in the abdominal cavity, molecularly characterized by the presence of a EWSR1::WT1 fusion transcript. Mouse models of muscular dystrophy, including LGMDR1, present an increased risk of soft tissue sarcomas. However, the DSRCT risk and general cancer risk in patients with LGMD is unknown. Here, we delineate the clinical, molecular, and genetic findings of a patient with LGMDR1 who developed a DSRCT. CASE REPORT The patient was a boy who was diagnosed at the age of 9 years with LGMDR1, caused by the biallelic pathogenic variants NP_000061.1:p.(Arg448Cys) and NP_000061.1:p.(Thr184ArgfsTer36) in CAPN3. At 17 years of age, a pathologic soft tissue mass was found in the right pelvis. Immunostaining was positive for Desmin and negative for Myogenin and MyoD1, and RNA sequencing showed a EWSR1::WT1 fusion transcript, confirming the diagnosis of DSRCT. The patient relapsed after 1 year and, following a second relapse, he was started on palliative treatment. No germline variants in childhood cancer predisposition genes were detected by whole genome sequencing. CONCLUSIONS We describe a patient with LGMDR1 who developed a DSRCT. Since associations between LGMD and pediatric cancer are hitherto unknown, further studies are warranted, as little information is currently published about the pediatric cancer risk in this patient group.

Desmoplastic Small Round Cell Tumor: a study of CT, MRI, PET/CT multimodal imaging features and their correlations with pathology

PURPOSE

Exploring the computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (FDG-PET)/CT Multimodal Imaging Characteristics of Desmoplastic Small Round Cell Tumor (DSRCT) to enhance the diagnostic proficiency of this condition.

METHODS

A retrospective analysis was performed on clinical data and multimodal imaging manifestations (CT, MRI, FDG-PET/CT) of eight cases of DSRCT. These findings were systematically compared with pathological results to succinctly summarize imaging features and elucidate their associations with both clinical and pathological characteristics.

RESULTS

All eight cases within this cohort exhibited abdominal-pelvic masses, comprising six solitary masses and two instances of multiple nodules, except for one case located in the left kidney, the remaining cases lacked a clear organ source. On plain images, seven cases exhibited patchy areas of low density within the masses, four cases showed calcification within the masses. Post-contrast imaging displayed mild-to-moderate, uneven enhancement. Larger masses displayed patchy areas without significant enhancement at the center. In the four MRI examinations, T1-weighted images exhibited uneven, low signal intensity, while T2-weighted images demonstrated uneven high signal intensity. Imaging unveiled four cases of liver metastasis, four cases of ascites, seven cases of lymph node metastasis, three cases of diffuse peritoneal thickening, and one case involving left ureter invasion with obstruction. In the FDG-PET/CT examinations of seven cases, multiple abnormal FDG accumulations were observed in the abdominal cavity, retroperitoneum, pelvis, and liver. One postoperative case revealed a new metastatic focus near the colonic hepatic region. The range of maximum standardized uptake values (SUVmax) for all lesions are 6.62-11.15.

CONCLUSIONS

DSRCT is commonly seen in young men, and the imaging results are mostly multiple lesions with no clear organ source. Other common findings include intratumoral calcification, liver metastasis, ascites, peritoneal metastasis, and retroperitoneal lymph node enlargement. The combined use of CT, MRI and FDG-PET/CT can improve the diagnostic accuracy and treatment evaluation of DSRCT. However, it is imperative to underscore that the definitive diagnosis remains contingent upon pathological examination.

Desmoplastic Small Round Cell Tumors of the Gastrointestinal Tract

Desmoplastic small round cell tumors (DSRCTs) of the gastrointestinal (GI) tract are a rare and highly aggressive variant of soft tissue sarcomas, predominantly affecting the abdominal region. These tumors are believed to originate from multipotent mesenchymal stem cells or primitive progenitor cells. They are composed of small round tumor cells associated with prominent stromal desmoplasia, polyphenotypic differentiation, and EWSR1::WT1 gene fusion. Diagnostically, DSRCTs present a significant challenge due to their histological resemblance to other small round cell tumors, such as Ewing sarcoma and rhabdomyosarcoma, necessitating the use of ancillary tests, including immunopanels and molecular analysis, to reach a definitive diagnosis. Immunohistochemical staining, including markers like cytokeratin, vimentin, desmin, and WT1, has proven valuable in differentiating DSRCTs from their mimickers. The prognosis of these tumors is highly dependent on factors such as tumor location and stage at diagnosis, and given their aggressive nature, a multidisciplinary approach may be required that combines surgical resection, chemotherapy, and radiation therapy, among other options. In this review, we provide a synopsis of the pathophysiology of DSRCTs and the latest diagnostic advancements, including the utility of molecular profiling and novel biomarkers.

Desmoplastic small round cell tumor: from genomics to targets, potential paths to future therapeutics

Desmoplastic Small Round Cell Tumor (DSRCT) is a highly aggressive pediatric cancer caused by a reciprocal translocation between chromosomes 11 and 22, leading to the formation of the EWSR1::WT1 oncoprotein. DSRCT presents most commonly in the abdominal and pelvic peritoneum and remains refractory to current treatment regimens which include chemotherapy, radiotherapy, and surgery. As a rare cancer, sample and model availability have been a limiting factor to DSRCT research. However, the establishment of rare tumor banks and novel cell lines have recently propelled critical advances in the understanding of DSRCT biology and the identification of potentially promising targeted therapeutics. Here we review model and dataset availability, current understanding of the EWSR1::WT1 oncogenic mechanism, and promising preclinical therapeutics, some of which are now advancing to clinical trials. We discuss efforts to inhibit critical dependencies including NTRK3, EGFR, and CDK4/6 as well as novel immunotherapy strategies targeting surface markers highly expressed in DSRCT such as B7-H3 or neopeptides either derived from or driven by the fusion oncoprotein. Finally, we discuss the prospect of combination therapies and strategies for prioritizing clinical translation.

Treatment of Abdominal Desmoplastic Small Round Cell Tumor Induces Acute Myeloid Leukemia-M5: A Case Report and Literature Review

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive malignancy. Most patients are diagnosed at a late stage with poor prognosis. The treatment usually includes combined intensive chemotherapy, cytoreductive surgery, radiotherapy, and targeted therapy. Due to the low incidence rate and dismal survival, there is currently a lack of case reports on DSRCT with concurrent leukemia. We report a case of a young patient who achieved disease stabilization for 14 months after receiving 6 cycles of chemotherapy and whole abdominal radiation therapy (WART), followed by consolidation treatment with anlotinib. However, the treatment was terminated due to the development of Acute Myeloid Leukemia-M5 (AML-M5). Multimodal therapy may provide a survival benefit for rare tumors that lack standard treatment. However, intensive chemotherapy and extensive radiotherapy carry a risk of inducing secondary malignancies. This is the first reported case of concurrent DSRCT and AML-M5 with short intervals between onset.

Desmoplastic small round cell tumor of the liver: diagnosing a rare case on liver biopsy

Desmoplastic small round-cell tumors (DSRCT) frequently develop in the retroperitoneum, pelvis, omentum, and mesentery. Here, we present an unusual case of primary DSRCT in the liver. The patient was an 11-year-old boy with multiple solid masses in the liver parenchyma. The tumor in the needle biopsy had a histology revealing a small round cell morphology and desmoplasia. It shows the immunohistochemical features of DSRCT and documentation of EWSR1-WT1 fusion.A potential diagnostic pitfall is exerted when evaluating liver biopsy, in which DSRCT is a great mimicker and may be easily confused with more common liver malignancies of childhood, such as hepatoblastoma, calcifying nested stromal-epithelial tumor, undifferentiated embryonal sarcoma, and other small round cell tumors, as well as the fibrolamellar variant of hepatocellular carcinoma. This distinction is critical because an accurate therapeutic approach requires a correct diagnosis.

Primary and secondary tumors of the peritoneum: key imaging features and differential diagnosis with surgical and pathological correlation

Peritoneal malignancies represent a diagnostic challenge for abdominal radiologists, oncologists, surgeons and pathologists in multidisciplinary teams, who must address their differential diagnosis, staging and treatment. In this article, we explain the pathophysiology of these processes and lay out the role of different imaging techniques in their evaluation. Then, we review the clinical and epidemiological aspects, the main radiological features and the therapeutic approaches for each primary and secondary peritoneal neoplasm, with surgical and pathological correlation. We further describe other rare peritoneal tumors of uncertain origin and a variety of entities that may mimic peritoneal malignancy. Finally, we summarize the key imaging findings of each peritoneal neoplasm to facilitate an accurate differential diagnosis that may impact patient management.Clinical relevance statementImaging plays an essential role in the evaluation of peritoneal malignancies, assessing their extension, detecting unfavorable sites of involvement and facilitating an accurate differential diagnosis, helping to choose the best therapeutic approach.

Intra-abdominal desmoplastic small round cell tumor: The European pediatric Soft tissue sarcoma Study Group (EpSSG) experience

BACKGROUND

This study describes the clinical findings of a consecutive series of pediatric and adolescent patients with a diagnosis of intra-abdominal desmoplastic small round cell tumor (DSRCT) prospectively enrolled in European pediatric Soft tissue sarcoma Study Group (EpSSG) protocols: the BERNIE study, the EpSSG MTS 2008 study, and the EpSSG NRSTS 2005 study.

METHODS

Patients aged less than 21 years with a diagnosis of DSRCT arising in the abdomen were included. All trials recommended a multimodal approach including intensive multidrug chemotherapy and loco-regional treatment with surgery and/or radiotherapy whenever possible.

RESULTS

The analysis included 32 cases (median age 13.7 years, male:female ratio 1.5:1). Three patients had localized tumors, seven had regionally disseminated disease, and 22 extraperitoneal metastases. All but one patient received multidrug chemotherapy and 11 had maintenance chemotherapy. Loco-regional treatment consisted of surgery only in seven cases, surgery plus adjuvant radiotherapy in 10, and radiotherapy only in six. Among the 17 cases who had radiotherapy, six had irradiation of the primary site, 10 had whole abdominopelvic radiotherapy plus boost to macroscopic residual disease, and one had irradiation to lung metastases only. With a median follow-up of 76 months (range: 18-124 months), 5-year event-free and overall survivals were 19.7% and 21.0%, respectively. Event-free survival was significantly worse for patients who did not receive loco-regional treatment (p-value .007).

CONCLUSIONS

The study confirmed that the outcome of patients with DSRCT remains dismal and did not improve over recent years despite an intensive multimodal treatment approach.

Desmoplastic small round cell tumor: from state of the art to future clinical prospects

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is an extremely rare and highly aggressive soft tissue sarcoma, presenting mainly in male adolescents and young adults with multiple nodules disseminated within the abdominopelvic cavity. Despite a multimodal approach including aggressive cytoreductive surgery, intensive multi-agent chemotherapy, and postoperative whole abdominopelvic radiotherapy, the prognosis for DSRCT remains dismal. Median progression-free survival ranges between 4 and 21 months, and overall survival between 17 and 60 months, with the 5-year overall survival rate in the range of 10-20%.

AREA COVERED

This review discusses the treatment strategies used for DSRCT over the years, the state of the art of current treatments, and future clinical prospects.

EXPERT OPINION

The unsatisfactory outcomes for patients with DSRCT warrant investigations into innovative treatment combinations. An international multidisciplinary and multi-stakeholder collaboration, involving both pediatric and adult sarcoma communities, is needed to propel preclinical model generation and drug development, and innovative clinical trial designs to enable the timely testing of treatments involving novel agents guided by biology to boost the chances of survival for patients with this devastating disease.

Selective Immunoreactivity for WT1 Carboxy-Terminus Distinguishes Desmoplastic Small Round Cell Tumor From its Histologic Mimics

Desmoplastic small round cell tumor (DSRCT) is an aggressive pediatric round cell sarcoma containing a characteristic EWSR1-WT1 gene fusion. In the absence of genetic data, distinguishing DSRCT from other small round cell tumors of childhood can be problematic due to overlapping histologic and immunohistochemical features. We studied the utility of immunohistochemistry with antibodies targeting both the amino-terminal and carboxy-terminal regions of the Wilms tumor-1 (WT1) protein in differentiating these groups of tumors. The study cohort included 33 cases of genetically confirmed pediatric round cell tumors (10 DSRCTs, 12 Wilms tumors, 10 Ewing sarcomas, and 1 CIC-rearranged sarcoma). Immunoreactivities and immunolocalization of both the WT1 amino-terminus and carboxy-terminus were scored and documented. All DSRCTs displayed selective reactivity for only the WT1 carboxy-terminus (10/10), while dual immunoreactivity for both the WT1 carboxy-terminus (12/12) and amino-terminus antibodies (12/12) were characteristic of Wilms tumors. CIC-rearranged sarcoma showed variable WT1 nuclear immunopositivity (1/1, 1/1) and Ewing sarcomas were consistently WT1-negative for both the WT1 amino-terminus (0/10) and carboxy-terminus (0/10). Dual WT1 amino-terminus and carboxy-terminus immunohistochemistry remains a helpful diagnostic tool in discriminating intraabdominal small round cell tumors, which serves as an adjunct to the genetic information in preventing misdiagnosis.

Desmoplastic Small Round Cell Tumor in a Pregnant Woman: A Case Report and Literature Review

Background: Desmoplastic small round cell tumor (DSRCT) is an aggressive malignant tumor commonly found in young men; most occurs in the abdominal cavity. Here we conducted an in-depth analysis of a pregnant patient in our hospital and explored all the case information in the literature on small round cell carcinoma of women. Case presentation: A 27-year-old pregnant woman underwent tumor resection in our hospital at 29 weeks gestational age for a large progressive shoulder lump. The postoperative pathology showed that the mass was a DSRCT. Genetic testing found no fusion gene. At 36 weeks gestation, a painful mass was found in the breast and proved to be a metastatic focus of the desmoplastic small round cell tumor. Twenty days after a successful cesarean section at 40 weeks gestation, she received the VAC-IE chemotherapy regimen, successfully completed the first course, but when awaiting the next chemotherapy, unfortunately, the patient died during follow-up due to tumor recurrence and metastasis. Conclusion: The treatment of DSRCT in pregnant women requires a multidisciplinary consultation, and the treatment and examination during pregnancy are subject to many constraints, which may have a negative impact on the patient's prognosis. Also, a review of the literature found that there is still no standard treatment protocol for DSRCT, and its prognosis in female patients is independent of age and tissue origin.

Intra-Abdominal Desmoplastic Small Round Cell Tumor: Current Treatment Options and Perspectives

Intra-abdominal desmoplastic small round cell tumor (IDSRCT) is a rare and highly malignant soft tissue neoplasm, which is characterized by rapid progression and poor prognosis. The mechanism underlying the development of this neoplasm remains elusive, but all cases are characterized by the chromosomal translocation t (11;22) (p13; q12), which results in a formation of EWSR1-WT1 gene fusion. The diagnosis of IDSRCT is often made with core-needle tissue biopsy specimens or laparoscopy or laparotomy. Immunohistochemical analyses have shown the co-expression of epithelial, neuronal, myogenic, and mesenchymal differentiation markers. FISH or reverse transcription polymerase chain reaction detecting EWS-WT1 fusion can be performed to assist in molecular confirmation. There is no standard of care for patients with IDSRCT currently, and majority of newly diagnosed patients received the aggressive therapy, which includes >90% resection of surgical debulking, high-dose alkylator-based chemotherapy, and radiotherapy. More recently, targeted therapy has been increasingly administered to recurrent IDSRCT patients and has been associated with improved survival in clinical conditions. Immunotherapy as a possible therapeutic strategy is being explored in patients with IDSRCT. In this review, we summarize currently available knowledge regarding the epidemiology, potential mechanisms, clinical manifestations, diagnosis, treatment, and prognosis of IDSRCT to assist oncologists in comprehensively recognizing and accurately treating this malignancy.

Postmarketing observational study of pazopanib in patients with metastatic soft tissue sarcoma in Japan

BACKGROUND

This study evaluated the safety and efficacy of pazopanib in patients with metastatic soft tissue sarcoma in routine clinical use in Japan.

METHODS

It was a multicentre, centrally registered and uncontrolled observational study in patients who received pazopanib for metastatic soft tissue sarcoma, with an observation period of 1 year after the start of drug administration. The study was conducted at 378 investigational sites in Japan from September 2012 to September 2019. Progression-free survival (PFS) and overall survival (OS) were the efficacy endpoints of the study.

RESULTS

A total of 1970 patients were enrolled. Of these, 680 with finalized study forms were included in the analysis. Overall, 649 patients were included in the safety analysis set, and 569 were included in the efficacy analysis set. Most of the patients (81.97%) experienced at least one adverse drug reaction (ADR); 22.34% of patients reported serious ADRs and 34.98% of patients experienced grade ≥ 3 ADRs in the safety set. Hypertension (40.37%) and hepatic dysfunction (26.50%) were the two most common ADRs. A total of 262 deaths were reported, of which 12 were due to ADRs. The median PFS was 3.09 months, whereas the median OS was not reached at the end of the 1-year observation period.

CONCLUSIONS

The safety and efficacy profiles in this postmarketing observational study were consistent with prior data and registration clinical trials. No new safety signals were observed while treating patients with metastatic soft tissue sarcoma with pazopanib.