Dedifferentiated Liposarcoma: Systemic Therapy Options

Pancreatic liposarcoma: A case report

Primary liposarcoma (LPS) of the pancreas is extremely rare. The present report describes an additional case of primary pancreatic LPS and reviews the current literature. A 40-year-old female patient that initially presented with a fever was subsequently found to have a pancreatic tumor. CT was used to identify a heterogeneous mass in the pancreatic head and body, which had a notable absence of fat components. The tumor exhibited slightly heterogeneous enhancement during the arterial phase, moderate enhancement in the venous phase and persistent enhancement in the delayed phase, with encapsulation of the common hepatic artery, splenic vein and portal vein. The patient underwent a successful distal pancreatectomy and splenectomy. Pathological examination and next-generation sequencing confirmed the diagnosis of dedifferentiated LPS (DDLPS). The present report elucidated the CT findings of this rare case of DDLPS of the pancreas, characterized by vascular invasion and progressive enhancement but without fat components, which can serve as a reference for the diagnosis of this uncommon tumor. The uncommon CT manifestation makes differentiation from pancreatic neuroendocrine tumors particularly challenging based on imaging characteristics.

Primary intracranial dedifferentiated liposarcoma: An extremely rare site with unusual histopathological findings

Primary intracranial sarcomas constitute a rare group of tumors, with the most common types described in the literature being chondrosarcoma and fibrosarcoma. Dedifferentiated liposarcoma (DDLS) is a high-grade sarcoma that sometimes metastasizes to the brain. However, a primary intracranial DDLS is exceedingly rare. A 45-year-old patient from the Middle East came to India for treatment. His magnetic resonance imaging (MRI) scans revealed a space-occupying lesion at the level of the lateral ventricle T2/fluid attenuated inversion recovery hyperintensity with peripheral edema. A T1 perfusion map showed high relative cerebral blood volume values in the peripheral part, suggesting a high-grade neoplasm. Gross total resection was performed, and histopathology showed a high-grade tumor composed of sheets of pleomorphic lipoblasts and epithelioid tumor cells arranged in nests and cords. Immunohistochemistry showed diffuse immunopositivity for MDM2, CDK4, and p16, while GFAP and OLIG2 were negative. Fluorescence in situ hybridization showed MDM2 amplification. Final diagnosis of DDLS was rendered. The patient had no systemic lesions elsewhere on positron emission tomography computed tomography scan.

Clinical course and prognostic factors of patients with dedifferentiated liposarcoma: a retrospective analysis

INTRODUCTION

Dedifferentiated liposarcoma (DDLPS) is a fairly common subtype of soft tissue sarcoma, but relatively little is known about the clinical course and prognostic factors of this mesenchymal malignancy.

METHODS

We performed a retrospective analysis of patients diagnosed with DDLPS at the University Hospital Leuven, Belgium between 1991 and 2022 based on an established clinical database and patient records.

RESULTS

We identified 259 patients with DDLPS, with the retroperitoneum as most common location of the primary tumor (47.5%). 204/259 patients (78.8%) patients had primary surgery. Radiotherapy was administered in the pre- (46/259, 17.8%) or postoperative setting (51/259, 19.7%). At diagnosis 28/259 (10.8%) patients presented with locally inoperable disease and 26/259 (10.0%) with synchronous metastasis. In patients who had primary surgery, local relapses were seen in 114/259 (44.0%) patients and 80/259 (30.9%) patients developed metachronous metastasis. A total of 48/259 (18.5%) patients developed both local relapse and metastasis. Patients with inoperable or metastatic disease were often treated with systemic therapy. The most common first-line systemic therapies were doxorubicin (51/98, 52.0%), doxorubicin combined with ifosfamide (12/98, 12.2%) and different types of experimental treatments (18/98, 18.4%). The median overall survival from first diagnosis of DDLPS to death of all causes was 70.5 months (95% confidence interval [CI] 56.6-98.6) for all patients, 10.9 months (95% CI 3.6-29.2) in patients with inoperable disease, 28.4 months (95% CI 1.3-199.3) for patients with local relapse and only 9.4 months (95% CI 1.2-25.9) for patients with metastatic disease. We identified lower age, primary surgery, absence of synchronous metastasis, absence of local relapse and treatment with experimental therapy as statistically significant favorable prognostic factors.

CONCLUSIONS

DDLPS is a subtype of soft tissue sarcoma with an aggressive clinical course and very poor prognosis, especially in patients with inoperable or metastatic disease. The results with classic chemotherapy are poor, and experimental treatments may be a preferred choice for individual patients. Data from this retrospective series can inform the design of future prospective and ongoing trials in this setting.

Dedifferentiated liposarcoma of transverse colon: a case report and review of the literature

Dedifferentiated liposarcoma (DDL) is an aggressive subtype of liposarcoma that rarely arises within the abdominal cavity. We describe the case of a 71-year-old female incidental transverse colon mass suspicious for colorectal cancer. Pre-operative biopsy at colonoscopy was not possible due to the lesion's extraluminal location; however, complete resection was achieved through left hemicolectomy. Histology confirmed DDL. Review of the literature found four additional cases of DDL in the transverse colon. Clinical presentation, management, and follow-up were reviewed, illustrating poor outcomes; three of the five cases died within 3 years of surgery. DDL is associated with higher rates of local recurrence, metastasis, and mortality compared to well-differentiated liposarcomas. While limited by its rarity, DDL in the transverse colon appears to follow similarly poor outcomes.

Giant dedifferentiated liposarcoma of the neck with osteosarcoma and chondrosarcoma components: A case report

Dedifferentiated liposarcoma (DDLPS) is a subtype of LPS characterized by two distinct levels of differentiation and morphological structures, comprising areas of well-differentiated LPS and dedifferentiated, non-lipogenic, highly malignant components. DDLPS most frequently occurs in the retroperitoneum and the soft tissues of the pelvis and limbs, and is rare in the head and neck region, accounting for only 1% of head and neck sarcomas. The present study describes the case of a 72-year-old male with a 30-year history of left upper limb numbness and heaviness. During physical examination, a tumor measuring ~13x22 cm was discovered in the left posterior region of the head and neck. The mass was hard in texture and had limited mobility. A biopsy of the lesion revealed a mesenchymal tumor rich in adipose components with ossification, containing heterologous elements primarily indicative of osteosarcoma, highly suggestive of DDLPS. A radical excision of the tumor was subsequently performed. The surgical specimen exhibits cross-sections with a gray-white to gray-yellow solid consistency, featuring gray-white, semi-transparent areas resembling cartilage. Immunohistochemical staining was positive for murine double minute 2 (MDM2), cyclin-dependent kinase 4 (CDK4), P16, P53, Vimentin and Ki-67, and negative for cytokeratin pan, S-100, CD34 and smooth muscle actin. Fluorescence in situ hybridization results indicated amplification of the MDM2 and CDK4 genes. In the present study, a case of a large DDLPS in the neck with components of osteosarcoma and chondrosarcoma was reported. There was no recurrence during the follow-up period. The pathological characteristics, diagnosis and current treatment methods for DDLPS were also described. Although cases of DDLPS have been reported, the number of cases described at this site remains limited to date, and it is currently not possible to accurately predict the treatment efficacy and prognosis.

Targeted transcriptomic analysis of well-differentiated and dedifferentiated liposarcoma reveals multiple dysregulated pathways including glucose metabolism, TGF-β, and HIF-1 signaling

Liposarcoma is the most prevalent sarcoma in adults representing 20% of all sarcomas with well-differentiated/dedifferentiated among the most common subtypes represented. Despite multimodality treatment approaches, there has not been any appreciable change in survival benefit in the past 10 years. The future of targeted therapy for WD/DDLPS is promising with the intention to spare multi-visceral removal due to radical surgical resection. Therefore, there is a need to expand upon the molecular landscape of WDLPS and DDLPS which can help identify potential therapeutic targets for the treatment of this disease. Targeted transcriptome analysis using the NanoString tumor signaling 360 panel revealed a dysregulation in glucose metabolism and HIF1 signaling pathways in both WDLPS and DDLPS when compared to normal fat controls. WDLPS, however, demonstrated upregulation of HIF-1A and TGF-β when compared to DDLPS by targeted transcriptome analysis and orthogonal validation by RT-qPCR suggesting activation of EMT pathway in WDLPS when compared to DDLPS. Our findings implicate a putative role for dysregulation in glucose metabolism, TGF-β and HIF1 signaling in the pathogenesis of both WD/DDLPS suggesting a possible proinflammatory tumor environment within WDLPS and subsequent activation of the TGF-β signaling pathway.

Primary dedifferentiated liposarcoma of the gallbladder: a case report and literature review

Background

Liposarcoma (LPS) is a kind of malignancy of soft tissue usually found in the retroperitoneal, limb, or neck region, and some may be detected with delayed symptoms (pain or palpable mass), and less frequently occurs in organs of the digestive system. In contrast, Dedifferentiated liposarcoma (DDLPS) is a common histological subtype of LPS. The present study reported a case of dedifferentiated liposarcoma originating in the gallbladder. Differentiated liposarcoma originating from the gallbladder is rarely reported.

Case description

A 64-year-old female patient presented to our hospital with a painless abdominal mass. Abdominal computed tomography (CT) showed that the gallbladder had lost its normal shape, and a 9.1 cm × 7.1 cm × 12.1 cm mass was seen in the area of the gallbladder fossa and the right upper abdomen below it, which had an irregular morphology, inhomogeneous density, and nodular calcification, with marked inhomogeneous enhancement on enhancement scan. Preoperative tumor markers and liver function indicators were not abnormal. With suspicion of a giant malignant tumor of the gallbladder, she underwent a cholecystectomy combined with abdominal mass resection. After surgery, the tumor and gallbladder, were completely resected, and postoperative pathological results confirmed the diagnosis of dedifferentiated liposarcoma deriving from gallbladder. After surgery, the patient and his family refused to continue treatment. After 15 months follow-up, the patient remains asymptomatic and does not show any signs of recurrence. And she is now under continued follow - up.

Conclusions

Treatment of dedifferentiated liposarcoma is still at exploratory stage, and a lack of clinical evidence for this condition might hinder access to clinical trials and studies. Currently, the treatment of choice for dedifferentiated liposarcoma remains radical resection. In the available clinical studies, there are no robust data to support clinical use of neoadjuvant and adjuvant radiochemotherapy. As with other diseases, the use of radiotherapy and chemotherapy before and after surgery may be a potential future treatment.

Left inguinal dedifferentiated liposarcoma and primary unclassified sarcoma of the left lung as synchronous multiple sarcomas: a case report

BACKGROUND

Pulmonary nodules in patients with soft tissue sarcomas are likely pulmonary metastases, whereas synchronous primary pulmonary sarcomas are rare. Without surgery, determining whether a solitary pulmonary nodule is a primary or metastatic nodule is difficult. Herein, we report a rare case of a primary pulmonary sarcoma that presented synchronously with a primary dedifferentiated liposarcoma.

CASE PRESENTATION

A 77-year-old man presented to another hospital with left inguinal swelling and a suspected recurrent inguinal hernia. Computed tomography revealed a left inguinal mass and pure-solid nodule in the left lung and the patient was referred to our hospital for detailed examination and treatment. The inguinal mass was pathologically diagnosed as a dedifferentiated liposarcoma using needle biopsy, whereas bronchoscopic biopsy revealed histological findings suggestive of a sarcoma; however, the primary site could not be determined. Positron emission tomography-computed tomography revealed no high-accumulation lesions except for the two sarcomas. We decided to perform surgery on both sarcomas for diagnostic and curative purposes. The surgical specimens showed that the two sarcomas were different. Based on the immunohistochemical staining findings of MDM2, a left inguinal dedifferentiated liposarcoma and primary pulmonary unclassified sarcoma were diagnosed. The patient displayed no evidence of recurrence 1 year after surgery.

CONCLUSIONS

We encountered a rare case of synchronous multiple primary sarcomas, one presenting in the lung and the other in the soft tissue. Surgery was required to achieve a definitive diagnosis for the patient, who achieved disease-free survival at 1 year. This case suggests that proactive resection of pulmonary nodules in patients with soft tissue sarcomas may be feasible as a diagnostic treatment if complete resection is achieved.

Deciphering the prognostic and therapeutic significance of BAG1 and BAG2 for predicting distinct survival outcome and effects on liposarcoma

Liposarcoma (LPS) is the second most common kind of soft tissue sarcoma, and a heterogeneous malignant tumor derived from adipose tissue. Up to now, the prognostic value of BAG1 or BAG2 in LPS has not been defined yet. Expression profiling data of LPS patients were collected from TCGA and GEO database. Survival curves were plotted to verify the outcome differences of patients based on BAG1 or BAG2 expression. Univariate and multivariate Cox regression models were used to analyze the prognostic ability of BAG1 or BAG2. Chaperone's regulators BAG1 and BAG2 were identified as prognostic biomarkers for LPS patients, which exhibited distinct expression patterns and survival outcome prediction performances. Patients with high BAG2 expression and/or low BAG1 expression had worse prognosis. Enrichment analysis showed that BAG1 was involved in negative regulation of TGF-β signaling. Low expression of BAG1 was associated with high abundance of regulatory T cells (Tregs). The 2-gene signature model further confirmed the improved risk assessment performance of BAG1 and BAG2: high risk patients displayed poor prognosis. BAG1 and BAG2 are supposed to be potential prognostic biomarkers for LPS and have impacts on liposarcomagenesis and immune infiltration in distinctive manners, which may function as potential therapy targets (BAG1 agonists/BAG2 inhibitors) for LPS.

Esophageal dedifferentiated liposarcoma resected by the cervical approach: a case report

BACKGROUND

While liposarcomas tend to mainly occur in the soft tissues of the extremities and retroperitoneum, esophageal liposarcoma is rare. Herein, we report a case of a patient who underwent complete resection of an esophageal dedifferentiated liposarcoma via the cervical approach, leading to the preservation of the esophagus.

CASE PRESENTATION

A 69-year-old man underwent an upper gastrointestinal endoscopy, as a result of which a submucosal-like tumor was observed. Upper gastrointestinal imaging showed a 12-cm tumor with a stalk arising from the esophageal entrance, extending to the middle intrathoracic esophagus, with a normal surface mucosa. Endoscopic ultrasound-fine needle aspiration biopsy showed that the nuclei of tumors cells were positive for murine double minute (MDM) and weakly positive for cyclin-dependent kinase 4 (CDK4). We diagnosed the tumor as the esophageal dedifferentiated liposarcoma, and planed tumor resection via the cervical approach. The tumor was successfully resected and the postoperative course was uneventful.

CONCLUSION

This case report highlights the use of tumor resection via the cervical approach as a good option for esophageal liposarcoma.

Transmediastinal primary pulmonary liposarcoma: Case report and review of management strategies

Soft tissue sarcomas account for less than 1% of new cancer diagnoses, approximately one in five of which are liposarcomas. These tumors typically arise in the deep tissues of the proximal extremity or retroperitoneum, with just under 3% presenting as primary intrathoracic neoplasms. We present an exceedingly rare and particularly unique presentation of primary lung liposarcoma which traversed the mediastinum into the contralateral hemithorax. This report highlights the primary characteristics of the disease and underscores the importance of a multidisciplinary approach to its successful treatment.

Well-differentiated liposarcomas and dedifferentiated liposarcomas: Systemic treatment options for two sibling neoplasms

Well-differentiated liposarcomas (WDLPS) and dedifferentiated liposarcomas (DDLPS) account for 60 % of all liposarcomas, reflecting the heterogeneity of this type of sarcoma. Genetically, both types of liposarcomas are characterized by the amplification of MDM2 and CDK4 genes, which indicates an important molecular event with diagnostic and therapeutic relevance. In both localized WDLPS and DDLPS of the retroperitoneum and the extremities, between 25 % and 30 % of patients have local or distant recurrence, even when perioperatively treated, with clear margins present. The systemic treatment of WDLPS and DDLPS remains a challenge, with anthracyclines as the gold standard for first-line treatment. Several regimens have been tested with modest results regarding their efficacy. Herein we discuss the systemic treatment options for WDLPS and DDLPS and review their reported clinical efficacy results.

Dedifferentiated Liposarcoma of the Rectum: A Case Report

Liposarcoma is a malignant soft tissue tumor that rarely involves the gastrointestinal tract. The dedifferentiated type typically carries the worst prognosis. Here, we describe a rare case of dedifferentiated liposarcoma of the rectum in a young male patient who was treated with surgical excision. Treatment is often difficult and there is no clear consensus on the benefits of radiotherapy or chemotherapy.

The pyroptosis-related signature predicts prognosis and influences the tumor immune microenvironment in dedifferentiated liposarcoma

Background

Dedifferentiated liposarcoma (DDL), a member of malignant mesenchymal tumors, has a high local recurrence rate and poor prognosis. Pyroptosis, a newly discovered programmed cell death, is tightly connected with the progression and outcome of tumor.

Objective

The aim of this study was to explore the role of pyroptosis in DDL.

Methods

We obtained the RNA sequencing data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression databases to identify different pyroptosis-related genes (PRGs) expression pattern. An unsupervised method for clustering based on PRGs was performed. Based on the result of cluster analysis, we researched clinical outcomes and immune microenvironment between clusters. The differentially expressed genes (DEGs) between the two clusters were used to develop a prognosis model by the LASSO Cox regression method, followed by the performance of functional enrichment analysis and single-sample gene set enrichment analysis. All of the above results were validated in the Gene Expression Omnibus (GEO) dataset.

Results

Forty-one differentially expressed PRGs were found between tumor and normal tissues. A consensus clustering analysis based on PRGs was conducted and classified DDL patients into two clusters. Cluster 2 showed a better outcome, higher immune scores, higher immune cells abundances, and higher expression levels in numerous immune checkpoints. DEGs between clusters were identified. A total of 5 gene signatures was built based on the DEGs and divided all DDL patients of the TCGA cohort into low-risk and high-risk groups. The low-risk group indicates greater inflammatory cell infiltration and better outcome. For external validation, the survival difference and immune landscape between the two risk groups of the GEO cohort were also significant. Receiver operating characteristic curves implied that the risk model could exert its function as an outstanding predictor in predicting DDL patients' prognoses.

Conclusion

Our findings revealed the clinical implication and key role in tumor immunity of PRGs in DDL. The risk model is a promising predictive tool that could provide a fundamental basis for future studies and individualized immunotherapy.

PDE3A Is a Highly Expressed Therapy Target in Myxoid Liposarcoma

Liposarcomas (LPSs) are a heterogeneous group of malignancies that arise from adipose tissue. Although LPSs are among the most common soft-tissue sarcoma subtypes, precision medicine treatments are not currently available. To discover LPS-subtype-specific therapy targets, we investigated RNA sequenced transcriptomes of 131 clinical LPS tissue samples and compared the data with a transcriptome database that contained 20,218 samples from 95 healthy tissues and 106 cancerous tissue types. The identified genes were referred to the NCATS BioPlanet library with Enrichr to analyze upregulated signaling pathways. PDE3A protein expression was investigated with immunohistochemistry in 181 LPS samples, and PDE3A and SLFN12 mRNA expression with RT-qPCR were investigated in 63 LPS samples. Immunoblotting and cell viability assays were used to study LPS cell lines and their sensitivity to PDE3A modulators. We identified 97, 247, and 37 subtype-specific, highly expressed genes in dedifferentiated, myxoid, and pleomorphic LPS subtypes, respectively. Signaling pathway analysis revealed a highly activated hedgehog signaling pathway in dedifferentiated LPS, phospholipase c mediated cascade and insulin signaling in myxoid LPS, and pathways associated with cell proliferation in pleomorphic LPS. We discovered a strong association between high PDE3A expression and myxoid LPS, particularly in high-grade tumors. Moreover, myxoid LPS samples showed elevated expression levels of SLFN12 mRNA. In addition, PDE3A- and SLFN12-coexpressing LPS cell lines SA4 and GOT3 were sensitive to PDE3A modulators. Our results indicate that PDE3A modulators are promising drugs to treat myxoid LPS. Further studies are required to develop these drugs for clinical use.

Discoidin Domain Receptor Tyrosine Kinase 1 (DDR1) Is a Novel Therapeutic Target in Liposarcoma: A Tissue Microarray Study

BACKGROUND

Liposarcoma is the most commonly diagnosed subtype of soft tissue sarcoma. As these tumors often arise near vital organs and neurovascular structures, complete resection can be challenging; consequently, recurrence rates are high. Additionally, available chemotherapeutic agents have shown limited benefit and substantial toxicities. There is, therefore, a clear and unmet need for novel therapeutics for liposarcoma. Discoidin domain receptor tyrosine kinase 1 (DDR1) is involved in adhesion, proliferation, differentiation, migration, and metastasis in several cancers. However, the expression and clinical importance of DDR1 in liposarcoma are unknown.

QUESTIONS/PURPOSES

The purposes of this study were to assess (1) the expression, (2) the association between DDR1 and survival, and (3) the functional roles of DDR1 in liposarcoma.

METHODS

The correlation between DDR1 expression in tumor tissues and clinicopathological features and survival was assessed via immunohistochemical staining of a liposarcoma tissue microarray. It contained 53 samples from 42 patients with liposarcoma and 11 patients with lipoma. The association between DDR1 and survival in liposarcoma was analyzed by Kaplan-Meier plots and log-rank tests. The DDR1 knockout liposarcoma cell lines were generated by CRISPR-Cas9 technology. The DDR1-specific and highly selective DDR1 inhibitor 7RH was applied to determine the impact of DDR1 expression on liposarcoma cell growth and proliferation. In addition, the effect of DDR1 inhibition on liposarcoma growth was further accessed in a three-dimensional cell culture model to mimic DDR1 effects in vivo.

RESULTS

The results demonstrate elevated expression of DDR1 in all liposarcoma subtypes relative to benign lipomas. Specifically, high DDR1 expression was seen in 55% (23 of 42) of liposarcomas and no benign lipomas. However, DDR1 expression was not found to be associated with poor survival in patients with liposarcoma. DDR1 knockout or treatment of 7RH showed decreased liposarcoma cell growth and proliferation.

CONCLUSION

DDR1 is aberrantly expressed in liposarcoma, and it contributes to several markers of oncogenesis in these tumors.

CLINICAL RELEVANCE

This work supports DDR1 as a promising therapeutic target in liposarcoma.

Giant dedifferentiated liposarcoma of the gastrocolic ligament: A case report

BACKGROUND

Dedifferentiated liposarcoma (DDLS) has a worse prognosis and occurs most commonly in the retroperitoneal region and rarely in the intraperitoneal region. Histological diagnosis was revolutionized by the combined contributions of histo-immuno-chemistry and molecular biology. Aside from surgery, there is no consensus on the optimal treatment for this chemoresistant cancer.

CASE SUMMARY

A thirty-year-old black female presented with a large painful abdominal mass occupying nearly the entire abdomen and progressive weight loss was admitted for surgery. Abdominal computed tomography showed a large heterogeneous mass of the mesentery that was sized 18 cm × 16 cm in size and had heterogeneous contrast enhancement. During laparotomy, en bloc excision of the large and multilobulated gastrocolic ligament mass was performed. The initial postoperative histopathological diagnosis was undifferentiated sarcoma. Finally, the results of immunohistochemistry and molecular biology allowed us to confirm the diagnosis of DDLS. The tumour followed an aggressive evolution with diffuse metastasis, causing the death of the patient less than 5 mo after the operation.

CONCLUSION

Dedifferentiated liposarcomas are rare tumours that typically originate in the retroperitoneum but may arise in unexpected locations.

Whole exome sequencing of well-differentiated liposarcoma and dedifferentiated liposarcoma in older woman: a case report

Background

Common kinds of soft tissue sarcomas (STS) include well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS). In this case, we present a comprehensive clinical profile of a patient who underwent multiple recurrences during the progression from WDLPS to DDLPS.

Case presentation

A 62-year-old Asian female underwent retroperitoneal resection of a large tumor 11 years ago, the initial pathology revealed a fibrolipoma-like lesion. Over the next six years, the patient underwent three resections for recurrence of abdominal tumors. Postoperative histology shows mature adipose tissue with scattered "adipoblast"-like cells with moderate-to-severe heterogeneous spindle cells, pleomorphic cells, or tumor giant cells. Immunohistochemistry (IHC) demonstrated positive staining for MDM2 and CDK4, confirming that the abdominal tumor was WDLPS and gradually progressing to DDLPS. Post-operative targeted sequencing and IHC confirmed the POC1B::ROS1 fusion gene in DDLPS. Whole-exome sequencing (WES) revealed that WDLPS and DDLPS shared similar somatic mutations and copy number variations (CNVs), whereas DDLPS had more mutated genes and a higher and more concentrated amplification of the chromosome 12q region. Furthermore, somatic mutations in DDLPS were significantly reduced after treatment with CDK4 inhibitors, while CNVs remained elevated.

Conclusion

Due to the high likelihood of recurrence of liposarcoma, various effective treatments should be taken into consideration even if surgery is the primary treatment for recurrent liposarcoma. To effectively control the course of the disease following surgery, combination targeted therapy may be a viable alternative to chemotherapy and radiotherapy in the treatment of liposarcoma.

Notch signaling regulates a metabolic switch through inhibiting PGC-1α and mitochondrial biogenesis in dedifferentiated liposarcoma

Human dedifferentiated liposarcoma (DDLPS) is a rare but lethal cancer with no driver mutations being identified, hampering the development of targeted therapies. We and others recently reported that constitutive activation of Notch signaling through overexpression of the Notch1 intracellular domain (NICDOE) in murine adipocytes leads to tumors resembling human DDLPS. However, the mechanisms underlying the oncogenic functions of Notch activation in DDLPS remains unclear. Here, we show that Notch signaling is activated in a subset of human DDLPS and correlates with poor prognosis and expression of MDM2, a defining marker of DDLPS. Metabolic analyses reveal that murine NICDOE DDLPS cells exhibit markedly reduced mitochondrial respiration and increased glycolysis, mimicking the Warburg effect. This metabolic switch is associated with diminished expression of peroxisome proliferator-activated receptor gamma coactivator 1α (Ppargc1a, encoding PGC-1α protein), a master regulator of mitochondrial biogenesis. Genetic ablation of the NICDOE cassette rescues the expression of PGC-1α and mitochondrial respiration. Similarly, overexpression of PGC-1α is sufficient to rescue mitochondria biogenesis, inhibit the growth and promote adipogenic differentiation of DDLPS cells. Together, these data demonstrate that Notch activation inhibits PGC-1α to suppress mitochondrial biogenesis and drive a metabolic switch in DDLPS.

The Conundrum of Dedifferentiation in a Liposarcoma at a Peculiar Location: A Case Report and Literature Review

Dedifferentiated liposarcoma of the deep soft tissue of the lower extremities is an infrequent finding. Myxoid liposarcoma is considered the most common soft tissue neoplasia arising in this anatomic region. Divergent differentiation usually occurs within well-differentiated liposarcoma and is exceedingly rare in a myxoid liposarcoma. We report a 32-year-old man who developed a dedifferentiated liposarcoma of the thigh on the background of a pre-existing myxoid liposarcoma. The gross examination of the surgical specimen showed a 11/7/2 cm tumour mass with solid tan-grey areas and focal myxoid degeneration. The microscopic examination revealed a malignant lipogenic proliferation, containing round cells with hyperchromatic nuclei and atypical lipoblasts, confined to the basophilic stroma with a myxoid aspect. Abrupt transition towards a hypercellular, non-lipogenic area consisting of highly pleomorphic spindle cells with atypical mitotic figures was also noted. Immunohistochemical staining was performed. Tumour cells in the lipogenic area were intensely positive for S100 and p16, and CD34 staining highlighted an arborizing capillary network. The dedifferentiated tumour areas showed positive MDM2 and CDK4 staining within neoplastic cells, with the Ki 67 proliferation marker expressed in approximately 10% of the cells. Wild-type TP53 protein expression pattern was documented. Thus, the diagnosis of a dedifferentiated liposarcoma was established. This paper aims to provide further knowledge about liposarcomas with divergent differentiation at peculiar locations, emphasizing the importance of histopathologic examination and immunohistochemical analysis for establishing the diagnosis and assessing the therapeutic response and prognosis of this condition.

A Mixed-Methods Study to Better Measure Patient-Reported Pain and Fatigue in Soft Tissue Sarcoma

INTRODUCTION

Pain and fatigue are commonly reported by patients with soft tissue sarcoma (STS) as distressing symptoms, yet no patient-reported outcome (PRO) measures have been validated or developed specifically for STS. This study aimed to develop novel PRO scales using existing item banks to measure pain and fatigue in STS.

METHODS

A three-stage mixed-methods approach was used. Stage 1: a literature review examined the development and validation of the European Organization for Research and Treatment of Cancer (EORTC) library, Patient-Reported Outcomes Measurement Information System (PROMIS) pain/fatigue item banks, Functional Assessment of Cancer Therapy-General, and FACIT-Fatigue. Conceptual models were developed for pain and fatigue. Stage 2: semi-structured interviews were conducted with clinical experts (n = 3) and STS patients (n = 28) to ensure conceptual coverage and cognitively debrief the selected PRO items. Stage 3: exploratory Rasch measurement theory (RMT) analyses were performed to examine the measurement properties of the proposed scales.

RESULTS

Stage 1: The conceptual model for fatigue was organized into two overarching domains: fatigability and fatigue, further split into two subdomains: symptoms and impact. The conceptual model for pain had one overarching domain split into two subdomains: descriptors and impact. Pain (n = 56) and fatigue (n = 40) items were selected from the EORTC item library. Stage 2: qualitative findings ensured conceptual coverage, provided insight into the relevance and comprehension of the items, and informed subsequent item reduction. Stage 3: The total item number was reduced to 43 (pain n = 18, fatigue n = 25). Exploratory RMT analyses supported the final scales' psychometric properties.

CONCLUSIONS

This mixed-methods research generated important information on the experience of pain and fatigue in specific subtypes of STS. Five novel PRO scales have been developed through careful item selection in consultation with experts and supported by qualitative and quantitative evidence. These scales may be of value to future clinical trials for STS.

Head pleomorphic sarcoma showing murine double minute 2 amplification without a well-differentiated liposarcoma component in a pediatric patient

BACKGROUND

Murine double minute 2 (MDM2) is an oncogene that inhibits p53, leading to decreased apoptosis. Sarcomas showing MDM2 amplification are rare among pediatric patients.

CASE

A 14-year-old boy presented with pleomorphic sarcoma of the head showing MDM2 amplification without a well-differentiated liposarcoma component. Although chemotherapy was initially performed to reduce the tumor size before surgery, the tumor did not shrink. The patient underwent complete surgical resection. Microscopic examination revealed a positive surgical margin; thus, postoperative proton-beam radiotherapy was performed. 3 years after the therapy, no sign of recurrence was observed.

CONCLUSION

Macroscopic surgical resection combined with adjuvant postoperative radiotherapy was effective against MDM2-amplified pleomorphic sarcoma refractory to neoadjuvant chemotherapy in a pediatric patient.

Genomic alterations and clinical outcomes in patients with dedifferentiated liposarcoma

PURPOSE

Patients with unresectable dedifferentiated liposarcoma (DDLPS) have poor overall outcomes. Few genomic alterations have been identified with limited therapeutic options.

EXPERIMENTAL DESIGN

Patients treated at Levine Cancer Institute with DDLPS were identified. Next generation sequencing (NGS), immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH) testing were performed on tumor tissue collected at diagnosis or recurrence/progression. Confirmation of genomic alterations was performed by orthologous methods and correlated with clinical outcomes. Univariate Cox regression was used to identify genomic alterations associated with clinical outcomes.

RESULTS

Thirty-eight DDLPS patients with adequate tissue for genomic profiling and clinical data were identified. Patient characteristics included: median age at diagnosis (66 years), race (84.2% Caucasian), and median follow-up time for the entire cohort was 12.1 years with a range from approximately 3.5 months to 14.1 years. Genes involved in cell cycle regulation, including MDM2 (74%) CDK4 (65%), and CDKN2A (23%), were amplified along with WNT/Notch pathway markers: HMGA2, LGR5, MCL1, and CALR (19%-29%). While common gene mutations were identified, PDE4DIP and FOXO3 were also mutated in 47% and 34% of patients, respectively, neither of which have been previously reported. FOXO3 was associated with improved overall survival (OS) (HR 0.37; p = 0.043) along with MAML2 (HR 0.30; p = 0.040). Mutations that portended worse prognosis included RECQL4 (disease-specific survival HR 4.67; p = 0.007), MN1 (OS HR = 3.38; p = 0.013), NOTCH1 (OS HR 2.28, p = 0.086), and CNTRL (OS HR 2.42; p = 0.090).

CONCLUSIONS

This is one of the largest retrospective reports analyzing genomic aberrations in relation to clinical outcomes for patients with DDLPS. Our results suggest therapies targeting abnormalities should be explored and confirmation of prognostic markers is needed. Dedifferentiated liposarcoma is one of the most common subtypes of soft tissue sarcoma yet little is known of its molecular aberrations and possible impact on outcomes. The work presented here is an evaluation of genetic abnormalities among a population of patients with dedifferentiated liposarcoma and how they corresponded with survival and risk of metastases. There were notable gene mutations and amplifications commonly found, some of which had interesting prognostic implications.

The Immune Contexture of Liposarcoma and Its Clinical Implications

Liposarcomas (LPS) are the most frequent malignancies in the soft tissue sarcoma family and consist of five distinctive histological subtypes, termed well-differentiated LPS, dedifferentiated LPS (DDLPS), myxoid LPS (MLPS), pleomorphic LPS, and myxoid pleomorphic LPS. They display variations in genetic alterations, clinical behavior, and prognostic course. While accumulating evidence implicates a crucial role of the tumor immune contexture in shaping the response to anticancer treatments, the immunological landscape of LPS is highly variable across different subtypes. Thus, DDLPS is characterized by a higher abundance of infiltrating T cells, yet the opposite was reported for MLPS. Interestingly, a recent study indicated that the frequency of pre-existing T cells in soft tissue sarcomas has a predictive value for immune checkpoint inhibitor (CPI) therapy. Additionally, B cells and tertiary lymphoid structures were identified as potential biomarkers for the clinical outcome of LPS patients and response to CPI therapy. Furthermore, it was demonstrated that macrophages, predominantly of M2 polarization, are frequently associated with poor prognosis. An improved understanding of the complex LPS immune contexture enables the design and refinement of novel immunotherapeutic approaches. Here, we summarize recent studies focusing on the clinicopathological, genetic, and immunological determinants of LPS.

Beyond targeting amplified MDM2 and CDK4 in well differentiated and dedifferentiated liposarcomas: From promise and clinical applications towards identification of progression drivers

Well differentiated and dedifferentiated liposarcomas (WDLPS and DDLPS) are tumors of the adipose tissue poorly responsive to conventional cytotoxic chemotherapy which currently remains the standard-of-care. The dismal prognosis of the DDLPS subtype indicates an urgent need to identify new therapeutic targets to improve the patient outcome. The amplification of the two driver genes MDM2 and CDK4, shared by WDLPD and DDLPS, has provided the rationale to explore targeting the encoded ubiquitin-protein ligase and cell cycle regulating kinase as a therapeutic approach. Investigation of the genomic landscape of WD/DDLPS and preclinical studies have revealed additional potential targets such as receptor tyrosine kinases, the cell cycle kinase Aurora A, and the nuclear exporter XPO1. While the therapeutic significance of these targets is being investigated in clinical trials, insights into the molecular characteristics associated with dedifferentiation and progression from WDLPS to DDLPS highlighted additional genetic alterations including fusion transcripts generated by chromosomal rearrangements potentially providing new druggable targets (e.g. NTRK, MAP2K6). Recent years have witnessed the increasing use of patient-derived cell and tumor xenograft models which offer valuable tools to accelerate drug repurposing and combination studies. Implementation of integrated "multi-omics" investigations applied to models recapitulating WD/DDLPS genetics, histologic differentiation and biology, will hopefully lead to a better understanding of molecular alterations driving liposarcomagenesis and DDLPS progression, as well as to the identification of new therapies tailored on tumor histology and molecular profile.

Surgery of intraabdominal giant dedifferentiated liposarcoma of ascending colon mesentery: A rare case report

Introduction

Liposarcoma, a lipogenic tumor of large deep-seated connective tissue space, presents the most common type of soft tissue sarcoma arising in the retroperitoneum. Liposarcoma that arises from colonic mesentery is especially a very rare disease. The present case describes a surgery of giant dedifferentiated liposarcoma at ascending colon mesentery.

Presentation of case

A 47-year-old South Korean man was admitted and presented with palpable abdominal mass. Abdominal pelvic computed tomography scan revealed a huge mass at his right sided abdomen (about 25 × 19 cm sized mass at right abdomen with encapsulation). After the surgery, the entire mass was completely excised en bloc with the ascending colon. The specimen consisted of multinodular, pinkish tanned, focally myxoid tissue, which measured up to 25.5 × 19 × 12.5 cm. Final pathological analysis reported dedifferentiated liposarcoma (high grade sarcoma) with MDM2 and CDK2 (+) in immunohistochemistry.

Conclusion

The present case report concerns a 47-year-old male with giant dedifferentiated liposarcoma arising from colonic mesentery and achieved en-bloc resection of liposarcoma with right hemicolectomy.

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Dedifferentiated liposarcoma arising from colonic mesentery is a rare form of the soft tissue sarcoma.

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In giant dedifferentiated liposarcoma, grossly complete resection is known as the better prognostic factor.

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liposarcoma excision with right hemicolectomy was inevitable for this case to achieve the complete resection due to colon wall invasion.

Effects of marital status on survival of retroperitoneal liposarcomas stratified by age and sex: A population-based study

BACKGROUND

Previous studies have shown that marital status is associated with survival in patients with a variety of cancer types, including lung cancer, prostate cancer, and bladder cancer. However, to date, the impact of marital status on the survival of patients with retroperitoneal liposarcomas (RPLs) has not been established.

METHODS

A total of 1211 eligible patients diagnosed with RPLs were identified in the Surveillance, Epidemiology, and End Results (SEER) database. The relationships between marital status and survival in patients with RPLs were assessed. Patients were stratified by age to determine whether an association exists between marital status and age. We also probed the association between marital status and survival in males and females.

RESULTS

Our findings suggest that divorced, separated, or widowed patients have more advanced cancer stages, and more of these patients do not undergo surgery. Meanwhile, divorced, separated, or widowed patients have worse survival outcomes than married patients (overall survival (OS): HR = 1.66 (95% CI, 1.12, 2.46)); cancer-specific survival (CSS): HR = 1.90 (95% CI, 1.13, 3.19)). OS does not differ between single patients and married patients (HR = 1.21 [95% CI, 0.81, 1.81]) or CSS (HR = 1.36 [95% CI, 0.80, 2.29]). In addition, these results demonstrate that being divorced, separated, or widowed can play a significant detrimental role in mortality in older and female patients.

CONCLUSION

Married patients have earlier disease stages at diagnosis and better survival outcomes than divorced, separated, or widowed patients with RPLs. In addition, this effect is especially pronounced in older people and females.

Development and Validation of a Prognostic Model to Predict the Prognosis of Patients With Retroperitoneal Liposarcoma: A Large International Population-Based Cohort Study

Background

Retroperitoneal liposarcomas (RPLs), sarcoma of mesenchymal origin, are the most common soft tissue sarcomas (STS) of the retroperitoneum. Given the rarity of RPLs, the prognostic values of clinicopathological features in the patients remain unclear. The nomogram can provide a visual interface to aid in calculating the predicted probability that a patient will achieve a particular clinical endpoint and communication with patients.

Methods

We included a total of 1,392 RPLs patients diagnosed between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. For nomogram construction and validation, patients in the SEER database were divided randomly into the training cohort and internal validation cohort at a ratio of 7:3, while 65 patients with RPLs from our center between 2010 and 2016 served as the external validation cohort. The OS curves were drawn using the Kaplan-Meier method and assessed using the log-rank test. Moreover, Fine and Gray's competing-risk regression models were conducted to assess CSS. Univariate and multivariate analyses were performed to select the prognostic factors for survival time. We constructed a predictive nomogram based on the results of the multivariate analyses.

Results

Through univariate and multivariate analyses, it is found that age, histological grade, classification, SEER stage, surgery constitute significant risk factors for OS, and age, classification, SEER stage, AJCC M stage, surgery, and tumor size constitute risk factors for CSS. We found that the nomogram provided a good assessment of OS and CSS at 1, 3, and 5 years in patients with RPLs (1-year OS: (training cohort: AUC = 0.755 (95% CI, 0.714, 0.796); internal validation cohort: AUC = 0.754 (95% CI, 0.681, 0.827); external validation cohort: AUC = 0.793 (95% CI, 0.651, 0.935)); 3-year OS: (training cohort: AUC = 0.782 (95% CI, 0.752, 0.811); internal validation cohort: AUC = 0.788 (95% CI, 0.736, 0.841); external validation cohort: AUC = 0.863 (95% CI, 0.773, 0.954)); 5-year OS: (training cohort: AUC = 0.780 (95% CI, 0.752, 0.808); internal validation cohort: AUC = 0.783 (95% CI, 0.732, 0.834); external validation cohort: AUC = 0.854 (95% CI, 0.762, 0.945)); 1-year CSS: (training cohort: AUC = 0.769 (95% CI, 0.717, 0.821); internal validation cohort: AUC = 0.753 (95% CI, 0.668, 0.838); external validation cohort: AUC = 0.799 (95% CI, 0.616, 0.981)); 3-year CSS: (training cohort: AUC = 0.777 (95% CI, 0.742, 0.811); internal validation cohort: AUC = 0.787 (95% CI, 0.726, 0.849); external validation cohort: AUC = 0.808 (95% CI, 0.673, 0.943)); 5-year CSS: (training cohort: AUC = 0.773 (95% CI, 0.741, 0.805); internal validation cohort: AUC = 0.768 (95% CI, 0.709, 0.827); external validation cohort: AUC = 0.829 (95% CI, 0.712, 0.945))). The calibration plots for the training, internal validation, and external validation cohorts at 1-, 3-, and 5-year OS and CSS indicated that the predicted survival rates closely correspond to the actual survival rates.

Conclusion

We constructed and externally validated an unprecedented nomogram prognostic model for patients with RPLs. The nomogram can be used as a potential, objective, and supplementary tool for clinicians to predict the prognosis of RPLs patients around the world.

Dedifferentiated liposarcoma (DDLPS) in the rectum: A case report

Dedifferentiated liposarcoma (DDLPS) is a rare subtype of liposarcoma with a poor prognosis. This current case report describes a rectal DDLPS in a 68-year-old Chinese male that presented with lower abdominal pain and weight loss. Computed tomography and magnetic resonance imaging were undertaken to evaluate the tumour. The patient underwent radical resection of the rectal tumour, sigmoid colostomy and partial ureterectomy. The tumour was positive for mouse double minute 2 by immunohistochemistry. The patient healed well but refused chemotherapy postoperatively for economic reasons. The tumour recurred and metastasized 4 weeks after the operation. After relevant treatment, the patient's condition deteriorated and he died of shock, metabolic acidosis, hyperlactataemia and acute renal failure. The case report also reviews the literature in terms of the clinical diagnosis, treatment and pathological characteristics of rectal DDLPS with the aim of improving the level of diagnosis and treatment.

Telomere as a Therapeutic Target in Dedifferentiated Liposarcoma

BACKGROUND

Well-differentiated (WD)/dedifferentiated (DD) liposarcoma (LPS) accounts for ~60% of retroperitoneal sarcomas. WDLPS and DDLPS divergently evolve from a common precursor and are both marked by the amplification of the 12q13-q15 region, leading to the abnormal expression of MDM2, CDK4, and HMGA2 genes. DDLPS is a non-lipogenic disease associated with aggressive clinical behavior. Patients have limited therapeutic options, especially for advanced disease, and their outcome remains largely unsatisfactory. This evidence underlines the need for identifying and validating DDLPS-specific actionable targets to design novel biology-driven therapies.

METHODS

Following gene expression profiling of DDLPS clinical specimens, we observed the up-regulation of "telomere maintenance" (TMM) pathways in paired DD and WD components of DDLPS. Considering the relevance of TMM for LPS onset and progression, the activity of a telomeric G-quadruplex binder (RHPS4) was assessed in DDLPS patient-derived cell lines.

RESULTS

Equitoxic concentrations of RHPS4 in DDLPS cells altered telomeric c-circle levels, induced DNA damage, and resulted in the accumulation of γ-H2AX-stained micronuclei. This evidence was paralleled by an RHPS4-mediated reduction of in vitro cell migration and induction of apoptosis/autophagy.

CONCLUSIONS

Our findings support telomere as an intriguing therapeutic target in DDLPS and suggest G-quadruplex binders as innovative therapeutic agents.

Establishment and characterization of a novel patient-derived cell line of dedifferentiated liposarcoma, NCC-DDLPS6-C1

Dedifferentiated liposarcoma (DDLPS) is morphologically characterized by well-differentiated liposarcomas associated with high-grade non-lipogenic sarcoma and molecularly characterized by the coamplification of MDM2 and CDK4(12q14-15). DDLPS is highly aggressive, and effective systemic chemotherapy has not been developed yet. In this study, we established a novel DDLPS cell line, NCC-DDLPS6-C1, as a potential tool for the development of novel therapies. NCC-DDLPS6-C1 cells were established from surgically resected tumor tissues of a patient with DDLPS. Amplification and overexpression of MDM2 and CDK4 were observed in NCC-DDLPS6-C1 cells. NCC-DDLPS6-C1 cells proliferated rapidly, invaded aggressively, and formed spheroids. Moreover, NCC-DDLPS6-C1 cells formed tumors in mice. These observations suggested that the malignant potentials that may reflect the original features of DDLPS were retained in the NCC-DDLPS6-C1. Anticancer drugs that significantly reduced the proliferation of NCC-DDLPS6-C1 cells were identified by drug library screening. Thus, NCC-DDLPS6-C1 may recapitulate the original genotypes and phenotypes, and we conclude that the NCC-DDLPS6-C1 cell line is a useful resource for the study of DDLPS.

Overall and net survival of patients with sarcoma between 2005 and 2010: Results from the French Network of Cancer Registries (FRANCIM)

BACKGROUND

Sarcomas are rare, heterogeneous, ubiquitously localized malignancies with many histologic subtypes and genomic patterns. The survival of patients with sarcoma has rarely been described based on this heterogeneity; therefore, the authors' objective was to estimate survival outcomes in patients who had sarcomas using the 2020 version of the World Health Organization classification of soft tissue and bone tumors.

METHODS

Patients older than 15 years who had incident sarcoma diagnosed between 2005 and 2010 were extracted from 14 French population-based cancer registries covering 18% of the French metropolitan population. Vital status for each patient was actively followed up to June 30, 2013. Net survival (NS) was estimated using the unbiased Pohar-Perme method.

RESULTS

Overall, 4202 patients were included. NS declined with increasing age at diagnosis. According to topographic groups, large 5-year NS disparities were observed, ranging from 47% among women with gynecologic sarcomas to 89% among patients with skin sarcomas. Patients with soft tissue, bone, and gastrointestinal sarcomas had 5-year NS rates of 53%, 61%, and 70%, respectively. Similar heterogeneity was observed according to histologic subtypes, with 5-year NS ranging from 19% for patients with angiosarcomas to 96% for patients with dermatofibrosarcomas. Patients with sarcoma who displayed missense mutations had a better 5-year NS (74%); those with MDM2-amplified sarcomas had the worst NS (45%).

CONCLUSIONS

NS rates in patients with sarcoma are presented here for the first time based on the 2020 World Health Organization classification applied to population-based registry data. Large prognostic heterogeneity was observed based on age, topographic and histologic groups, and genomic alteration profiles, constituting a benchmark for future studies and clinical trials.

Expression of the preadipocyte marker ZFP423 is dysregulated between well-differentiated and dedifferentiated liposarcoma

BACKGROUND

Well-differentiated and dedifferentiated liposarcomas are rare soft tissue tumors originating in adipose tissue that share genetic abnormalities but have significantly different metastatic potential. Dedifferentiated liposarcoma (DDLPS) is highly aggressive and has an overall 5-year survival rate of 30% as compared to 90% for well-differentiated liposarcoma (WDLPS). This discrepancy may be connected to their potential to form adipocytes, where WDLPS is adipogenic but DDLPS is adipogenic-impaired. Normal adipogenesis requires Zinc Finger Protein 423 (ZFP423), a transcriptional coregulator of Perixosome Proliferator Activated Receptor gamma (PPARG2) mRNA expression that defines committed preadipocytes. Expression of ZFP423 in preadipocytes is promoted by Seven-In-Absentia Homolog 2 (SIAH2)-mediated degradation of Zinc Finger Protein 521 (ZFP521). This study investigated the potential role of ZFP423, SIAH2 and ZFP521 in the adipogenic potential of WDLPS and DDLPS.

METHODS

Human WDLPS and DDLPS fresh and paraffin-embedded tissues were used to assess the gene and protein expression of proadipogenic regulators. In parallel, normal adipose tissue stromal cells along with WDLPS and DDLPS cell lines were cultured, genetically modified, and induced to undergo adipogenesis in vitro.

RESULTS

Impaired adipogenic potential in DDLPS was associated with reduced ZFP423 protein levels in parallel with reduced PPARG2 expression, potentially involving regulation of ZFP521. SIAH2 protein levels did not define a clear distinction related to adipogenesis in these liposarcomas. However, in primary tumor specimens, SIAH2 mRNA was consistently upregulated in DDLPS compared to WDLPS when assayed by fluorescence in situ hybridization or real-time PCR.

CONCLUSIONS

These data provide novel insights into ZFP423 expression in adipogenic regulation between WDLPS and DDLPS adipocytic tumor development. The data also introduces SIAH2 mRNA levels as a possible molecular marker to distinguish between WDLPS and DDLPS.

Establishment and characterization of NCC-DDLPS5-C1: a novel patient-derived cell line of dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is a highly aggressive subtype of liposarcoma that is morphologically defined as a transition from a well-differentiated lipomatous component to a non-lipogenic one. Curative therapy for DDLPS is complete resection, and the benefits of current systemic chemotherapy remain marginal. Although DDLPS is molecularly characterized by co-amplification of MDM2 and CDK4 (12q14-15) and detailed genomic analyses have been conducted by multiple research groups, the effects of molecular targeted drugs are marginal, and novel therapeutic modalities are required. Although patient-derived cell lines are pivotal for cancer research, no DDLPS cell lines are currently available from public cell repositories. Accordingly, in this study, we established a novel DDLPS cell line, NCC-DDLPS5-C1, using surgically resected tumor tissues from a patient with DDLPS. NCC-DDLPS5-C1 cells exhibited typical gene amplification, overexpression of MDM2 and CDK4, and other DNA copy number alterations. The NCC-DDLPS5-C1 cells were capable of rapid cell proliferation, aggressive invasion, and spheroid formation, but not tumor formation in mice. We reported the utility of NCC-DDLPS5-C1 cells for a drug-response assay to detect anticancer drugs that significantly attenuated cell proliferation. Thus, we concluded that the NCC-DDLPS5-C1 cell line could be a useful resource for the study of DDLPS. Considering the diversity of disease in terms of clinical outcomes, continuous efforts are required to develop more patient-derived cancer models with different clinical and pathological backgrounds.

Overview of systemic therapy options in liposarcoma, with a focus on the activity of selinexor, a selective inhibitor of nuclear export in dedifferentiated liposarcoma

Liposarcoma (LPS) is a common soft tissue sarcoma that encompasses diverse subtypes of well-differentiated/dedifferentiated, myxoid/round cell, and pleomorphic LPS. There is heterogeneity among the various LPS types with regard to prognosis, molecular pathogenesis, and response to treatment. Well-differentiated (WDLPS) and dedifferentiated liposarcoma (DDLPS) are most common types, which share common genetic alteration of chromosome 12q13-15 amplification resulting in amplification of oncogenes, including MDM2 (Mouse double minute 2), CDK4 (cyclin-dependent kinase 4), and HMGA2 (High mobility group protein AT-hook 2). Despite sharing the same molecular alteration, DDLPS has a worse prognosis, with a higher recurrence rate and higher propensity for metastases compared to WDLPS. Here we provide an overview of the LPS treatment landscape focusing on recent developments in the treatment of DDLPS with a focus on selinexor. Selinexor, a selective inhibitor of XPO1, was recently evaluated in a phase 3 trial, the first prospective randomized trial in DDLPS, and we discuss its efficacy in context of other available agents for DDLPS.

Case report: Two cases of primary paratesticular liposarcoma

Paratesticular liposarcoma is a sporadic urological tumor. We report the clinical presentation, treatment course, and prognosis of 2 cases of primary paratesticular liposarcoma with different pathological types, with the aim of further understanding the diagnosis and treatment of this rare disease. Case 1 was a 53-years-old male patient who presented with left scrotal enlargement with swelling 3 years ago and was considered to have a testicular malignancy on preoperative CT scan and enhanced MRI. The patient underwent resection of the left scrotal mass and left orchiectomy under general anaesthesia. Histopathological study confirmed the diagnosis of dedifferentiated liposarcoma. At the 4-months follow-up, no local recurrence or distant metastasis was observed. Case 2 is a 42-years-old male patient with a left scrotal mass which was discovered six months ago. Preoperatively, he underwent CT plain and enhanced MRI examinations suggesting an intra-scrotal occupancy. The patient underwent scrotoscopic excision of the left scrotal mass under general anesthesia. Histopathological studies confirmed the diagnosis of highly differentiated liposarcoma. At the 10-months follow-up, no local recurrence or distant metastasis was observed. Preoperative differential diagnosis of paratesticular liposarcoma should be noted with testicular tumor and extra-abdominal hernia. Extensive local excision and, if necessary, concomitant radical testicular resection is the treatment of choice. If the tumor in the scrotum spreads to the inguinal region, surgical removal with the aid of a scrotoscope may be attempted. This procedure avoids the formation of a large incision in the inguinal region compared to traditional open surgery. Patients commonly experience local recurrence and less distant metastases after surgery, so long-term follow-up is recommended.

A Rare Case of Dedifferentiated Retroperitoneal Liposarcoma Presenting As Cardiac-Sounding Chest Pain

Retroperitoneal liposarcomas (RPL) are rare mesenchymal tumours with an annual incidence of 2.7 cases per million. Well-differentiated liposarcomas (WDLs) and dedifferentiated liposarcomas (DDLs) are the most common subtype. WDLs are widely known to be low-grade tumours that are less likely to metastasise and easily resected. In contrast, DDLs are high-grade aggressive metastatic tumours with mortality rates between 50% and 70%.

We present an unusual case of a 47-year-old male with a background of hypertension presenting with cardiac-sounding chest pain. Initially managed as an acute coronary syndrome (ACS), he eventually underwent a CT scan which revealed a 20x18x17cm retroperitoneal complex mass with possible infiltrates to the posterior wall of the greater curvature of the stomach. Ultrasound-guided biopsy and subsequent histopathology analysis revealed DDL consistent with MDM2 amplification.

This case highlights how RPL can present with diagnostic difficulties. Multidisciplinary input from haematology, surgery and specialist teams is vital to optimise patient management.

Dedifferentiated Liposarcoma of the Transverse Colon

While liposarcoma is one of the most common soft tissue sarcomas, it is rarely seen within the gastrointestinal tract, and even less frequently seen within the colon. Dedifferentiated liposarcoma is a subtype of liposarcoma, which along with the pleomorphic subtype is considered a high-grade, aggressive tumor; both possess the ability to metastasize and are associated with decreased survival. Despite complete resection, recurrence is common. While surgical excision is the cornerstone of treatment for liposarcoma of the colon, there is no consensus on adjuvant therapies. We present the case of a 66-year-old woman who presented with abdominal pain with rectal bleeding and was found on colonoscopy to have a high-grade dedifferentiated liposarcoma of the transverse colon. She underwent robotic segmental colectomy. Due to absence of nodal involvement or distal metastasis, adjuvant therapy was not administered. On 1-year follow-up, the patient remains disease free.

Establishment and Characterization of NCC-DDLPS4-C1: A Novel Patient-Derived Cell Line of Dedifferentiated Liposarcoma

Dedifferentiated liposarcoma (DDLPS) is a highly malignant sarcoma characterized by the co-amplification of MDM2 and CDK4. Although systemic chemotherapy is recommended for unresectable or metastatic cases, DDLPS is insensitive to conventional chemotherapy, leading to an unfavorable prognosis. Therefore, novel treatment methods are urgently required. Patient-derived cell lines are essential in preclinical studies. Recently, large-scale screening studies using a number of cell lines have been actively conducted for the development of new therapeutic drugs. However, the DDLPS cell line cannot be obtained from public cell banks owing to its rarity, hindering screening studies. As such, novel DDLPS cell lines need to be established. Accordingly, this study aimed to establish a novel DDLPS cell line from surgical specimens. The cell line was named NCC-DDLPS4-C1. NCC-DDLPS4-C1 cells retained copy number alterations corresponding to the original tumors. Further, the cells demonstrated constant growth, spheroid formation, and equivalent invasiveness to MG63 osteosarcoma cells. We also conducted drug screening and integrated the results with those of the previously reported DDLPS cell lines. Consequently, we identified the histone deacetylase inhibitor romidepsin as a novel candidate drug. In conclusion, the NCC-DDLPS4-C1 cell line is a useful tool for the basic study of DDLPS.

Clinical Application of Chromosome Microarray Analysis in the Diagnosis of Lipomatous Tumors

Well-differentiated liposarcoma/atypical lipomatous tumor (WDLS/ALT) and dedifferentiated liposarcoma (DDLS) have characteristic supernumerary ring and giant marker chromosomes involving the chromosomal region 12q13-15 which contains MDM2 (12q15), CDK4 (12q14.1), HMGA2 (12q14.3), YEATS4 (12q15), CPM (12q15), and FRS2 (12q15). Detecting MDM2 amplification by fluorescence in situ hybridization (FISH) is considered to be the gold standard for the diagnosis of WDLS/ALT and DDLS. In this study, formalin fixed paraffin embedded clinical specimens (16 liposarcomas and 19 benign lipomatous tumors) were used to detect MDM2 amplification and other chromosomal alterations in WDLS/ALT and DDLS by single nucleotide polymorphism-based chromosome microarray (CMA). All 16 liposarcomas showed MDM2 amplification with a MDM2/cep12 ratio from 2.4 to 8.4 by CMA. Ten (62.5%) of these cases had CDK4/cep12 ratio ≥2.0. All the cases without CDK4 amplification were from the thigh. The MDM2/cep12 ratio of all the benign lipomatous tumors (19/19) was within the normal limits. Twenty-one of the 35 benign lipomatous tumors and liposarcomas were also tested for MDM2 amplification by FISH. All the FISH results were consistent with the CMA results (100%). Along with MDM2 amplification, all 16 liposarcomas (100%) also showed amplification of YEATS4, CPM and FRS2. Only 11 of 16 (69%) cases showed HMGA2 amplification. In conclusion, this study demonstrated that CMA on routine formalin fixed paraffin embedded tissue is a sensitive and specific clinical test for detection of MDM2 gene amplification. Moreover, CMA allows simultaneous detection of genomic changes of interest including CDK4 and others, which provides enriched information for diagnosing lipomatous tumors.

Biology and Management of Dedifferentiated Liposarcoma: State of the Art and Perspectives

Dedifferentiated liposarcoma (DDL) is defined as the transition from well-differentiated liposarcoma (WDL)/atypical lipomatous tumor (ALT) to non-lipogenic sarcoma, which arises mostly in the retroperitoneum and deep soft tissue of proximal extremities. It is characterized by a supernumerary ring and giant marker chromosomes, both of which contain amplified sequences of 12q13-15 including murinedouble minute 2 (MDM2) and cyclin-dependent kinase 4 (CDK4) cell cycle oncogenes. Detection of MDM2 (and/or CDK4) amplification serves to distinguish DDL from other undifferentiated sarcomas. Recently, CTDSP1/2-DNM3OS fusion genes have been identified in a subset of DDL. However, the genetic events associated with dedifferentiation of WDL/ALT remain to be clarified. The standard treatment for localized DDL is surgery, with or without radiotherapy. In advanced disease, the standard first-line therapy is an anthracycline-based regimen, with either single-agent anthracycline or anthracycline in combination with the alkylating agent ifosfamide. Unfortunately, this regimen has not necessarily led to a satisfactory clinical outcome. Recent advances in the understanding of the pathogenesis of DDL may allow for the development of more-effective innovative therapeutic strategies. This review provides an overview of the current knowledge on the clinical presentation, pathogenesis, histopathology and treatment of DDL.

Establishment and characterization of NCC-DDLPS3-C1: a novel patient-derived cell line of dedifferentiated liposarcoma

Dedifferentiated liposarcoma (DDLPS) is a highly malignant subtype of liposarcoma, with characteristic amplification of MDM2 and CDK4 (12q14-15). It is caused by the dedifferentiation of well-differentiated liposarcoma. DDLPS is refractory to conventional chemotherapy; thus, surgical resection is the primary treatment modality. However, complete resection of DDLPS is difficult because of its deep location, which results in poor prognosis. Therefore, novel systemic chemotherapy is required to improve the clinical outcome. Patient-derived cell lines are important tools in the development of novel chemotherapy. However, there are no DDLPS cell lines available from public cell banks. In this study, we established a novel DDLPS cell line, NCC-DDLPS3-C1, using a surgically resected specimen from a patient with DDLPS. NCC-DDLPS3-C1 cells retained the characteristic gene amplification of MDM2 and CDK4. In addition, other gene amplifications and losses related to the poor prognosis of DDLPS were also observed in concordance with the original tumor. The cells also exhibited rapid cell proliferation, aggressive invasion ability, spheroid formation ability, and tumorigenic ability in nude mice. Furthermore, a drug-screening test showed significant antiproliferative effects of proteasome inhibitors and HDAC inhibitors. Thus, the NCC-DDLPS3-C1 cell line should be a useful tool for the development of novel chemotherapy for DDLPS.

Selinexor versus doxorubicin in dedifferentiated liposarcoma PDXs: evidence of greater activity and apoptotic response dependent on p53 nuclear accumulation and survivin down-regulation

BACKGROUND

Dedifferentiated liposarcoma (DDLPS), a tumor that lacks effective treatment strategies and is associated with poor outcomes, expresses amplified MDM2 in the presence of wild-type p53. MDM2 ubiquitination of p53 facilitates its XPO1-mediated nuclear export, thus limiting p53 tumor suppressor functions. Consequently, nuclear export is a rational target in DDLPS. We directly compared the antitumor activity of the first-in class XPO1 inhibitor selinexor and doxorubicin, the standard front-line therapy in sarcomas, in DDLPS patient-derived xenografts (PDXs) and primary cell lines.

METHODS

Drug activity was assessed in three PDXs (and two corresponding cell lines) established from the dedifferentiated component of primary untreated retroperitoneal DDLPS with myogenic (N = 2) and rhabdomyoblastic (N = 1) differentiation from patients who underwent surgery. These models were marked by amplification of MDM2, CDK4 and HMGA2 genes.

RESULTS

Selinexor was moderately active in the three PDXs but achieved greater tumor response compared to doxorubicin (maximum tumor volume inhibition: 46-80 % vs. 37-60 %). The PDX harboring rhabdomyoblastic dedifferentiation showed the highest sensitivity to both agents. PDX response to selinexor and doxorubicin was not associated with the extent of MDM2 and CDK4 gene amplification. Interestingly, the most chemosensitive PDX model showed the lowest extent of HMGA2 amplification. Selinexor was also more efficient than doxorubicinin in inducing an apoptotic response in PDXs and cell lines. Consistently, an increased nuclear accumulation of p53 was seen in all selinexor-treated models. In addition, a time-dependent decrease of survivin expression, with an almost complete abrogation of the cytoplasmic anti-apoptotic pool of this protein, was observed as a consequence of the decreased acetylation/activation of STAT3 and the increased ubiquitination of nuclear survivin.

CONCLUSIONS

Selinexor showed a moderate antitumor activity in three DDLPS PDXs, which was, however, consistently higher than doxorubicin across all different models regardless the extent of MDM2 amplification and the histological differentiation. The depletion of survivin protein seems to significantly contribute to the induction of apoptosis through which selinexor exerts its antitumor activity.

Primary dedifferentiated Liposarcoma of vagina: a first case report

BACKGROUND

Dedifferentiated liposarcoma, one of the most deadly types of soft tissue sarcoma, is an aggressive and high-grade form of liposarcoma. Liposarcoma occurs most commonly in the retroperitoneum, extremities and trunk, but less frequently in the female genital tract. The vagina is a very rare site of origin. Herein we report the first case of dedifferentiated Liposarcoma deriving from vagina and discuss its clinical course.

CASE PRESENTATION

A 38-year-old female patient presented to our institution with a painless vaginal mass. Abdominal computed tomography showed a 17.6 cm× 10.4 cm solid mass originating from the right lateral wall of her vagina. Then she underwent complete surgical resection of the tumor mass, and postoperative pathological result confirmed the diagnosis of dedifferentiated liposarcoma deriving from vagina. Six courses of combination chemotherapy with pirarubicin plus ifosfamide were performed after surgery. The patient remains with no evidence of disease recurrence with 13 months of follow-up.

CONCLUSIONS

Liposarcoma is very rare in female genital tract, and more rare for dedifferentiated liposarcoma in gynecologic field. Little is known about the clinical characteristics, pathological diagnosis, prognosis and optimal management strategy of vaginal dedifferentiated liposarcoma. Complete surgical resection followed by systemic chemotherapy is suggested to be standard treatment for dedifferentiated liposarcoma. Combination chemotherapy with pirarubicin and ifosfamide may be effective for treating vaginal dedifferentiated liposarcoma.

Efficacy and safety of anlotinib in patients with unresectable or metastatic well-differentiated/dedifferentiated liposarcoma: a single-center retrospective study

Treatment options for unresectable local recurrence or metastatic well-differentiated/dedifferentiated liposarcoma (WDLS/DDLS) remain limited. Different liposarcoma subtypes have varying clinical features and sensitivities to treatment regimens. The multitarget tyrosine kinase inhibitors (TKIs), such as pazopanib and regorafenib, have been approved for use in nonadipocytic soft tissue sarcomas (STS). Anlotinib, another TKI, has been approved in China for treating metastatic STS that has progressed after the use of anthracycline-based regimens. In this study, we aimed to evaluate the role of anlotinib in the treatment of local recurrence or metastatic WDLS/DDLS. From August 2018 to June 2020, 17 patients with unresectable local recurrence or metastatic WDLS/DDLS treated with anlotinib in our center were included. The follow-up cutoff time was set as 20 October 2020. Baseline and observation indicators were collected and analyzed. Estimated median progression-free survival (PFS) was 27.9 weeks, the PFS rate at 24 weeks was 58.8%, overall survival (OS) was 56.6 weeks, the disease control rate was 64.7% and no complete response or partial response was detected. Grade 3/4 adverse events occurred in four cases and could be managed. Anlotinib is a potential treatment option for unresectable local recurrence or metastatic WDLS/DDLS.