Putative multifunctional signature of lung metastases in dedifferentiated chondrosarcoma

[Rare forms of dedifferentiated chondrosarcomas: About 3 cases]

Conventional chondrosarcoma is the most common primary malignant bone tumor in adults. Dedifferentiated chondrosarcomas represent 10 to 15% of conventional chondrosarcomas and constitute a high-grade subtype with a poor prognosis, with a 5-year survival rate of 24%. These tumors are characterized by a mutation in one of the isocitrate dehydrogenase (IDH) 1 or 2 genes in 70% of cases. Histological diagnosis requires a biphasic morphology combining a low-grade conventional chondrosarcoma component with a high-grade non-cartilaginous sarcomatoid component. In the literature, this dedifferentiated component most often corresponds to an osteosarcoma or an undifferentiated sarcomatous component. This article describes three cases of dedifferentiated chondrosarcomas: two with bone localization and one with laryngeal cartilaginous localization presenting a rare dedifferentiation component, either epithelial or rhabdomyosarcomatous, which may pose a diagnostic challenge, particularly in micro-biopsy samples. The mechanism of dedifferentiation is still poorly understood, and the origin of the dedifferentiated component remains controversial.

Dedifferentiated Chondrosarcoma: Diagnostic Controversies and Emerging Therapeutic Targets

PURPOSE OF REVIEW

The pathogenesis of dedifferentiated chondrosarcoma is controversial, and no genetic abnormality has consistently been identified in the disease. Focusing on the diagnostic challenges encountered in dedifferentiated chondrosarcoma, the following review aims at summarizing the tumor's active neoplastic pathways while highlighting therapeutic modalities that could potentially be explored to enhance patient survivorship.

RECENT FINDINGS

Owing to the challenging examination of small needle biopsy sampling as well as the disease's overlapping morphological and immunohistochemical features with other bone and soft-tissue sarcomas, the diagnosis of dedifferentiated chondrosarcoma can be problematic. While combined doxorubicin- and cisplatin-based regimens remain the first-line systemic chemotherapy in the disease, ~50% of tumors carry EXT1/2 or IDH1/2 mutations, advancing EXT or IDH inhibitors as potential alternative therapies, respectively. Despite systemic chemotherapy, dedifferentiated chondrosarcoma remains an aggressive tumor with dismal prognosis and limited survival. A multidisciplinary collaboration across multiple cancer centers is warranted to yield an accurate diagnosis, understand the disease's underlying pathogenesis, develop adequate treatment, and improve patient survivorship.

Dedifferentiated Chondrosarcoma from Molecular Pathology to Current Treatment and Clinical Trials

Dedifferentiated chondrosarcoma (DDCS) is a rare subtype of chondrosarcoma, a primary cartilaginous malignant neoplasm. It accounts for up to 1-2% of all chondrosarcomas and is generally associated with one of the poorest prognoses among all chondrosarcomas with the highest risk of metastasis. The 5-year survival rates range from 7% to 24%. DDCS may develop at any age, but the average presentation age is over 50. The most common locations are the femur, pelvis humerus, scapula, rib, and tibia. The standard treatment for localised disease is surgical resection. Most patients are diagnosed in unresectable and advanced stages, and chemotherapy for localised and metastatic dedifferentiated DDCS follows protocols used for osteosarcoma.

The transcription co-factor JAB1/COPS5, serves as a potential oncogenic hub of human chondrosarcoma cells in vitro

Chondrosarcoma (CS) is the second most common skeletal malignancy in humans. High-grade CS is aggressive and extremely resistant to chemo- and radio-therapies. The lack of effective treatment options warrants the development of novel therapies. The evolutionarily conserved transcriptional co-factor JAB1 (also known as COPS5/CSN5) has emerged as a novel regulator of tumorigenesis. JAB1 overexpression occurs in many common cancers and is associated with poor prognosis. However, the role of JAB1 in CS pathogenesis was completely unknown. To study JAB1's function in CS, we performed shRNA knockdown (KD) of JAB1 in two high-grade human CS cell lines, SW1353 and Hs819.T, and observed significantly decreased proliferation and colony formations, and increased apoptosis in both CS cell lines upon JAB1-KD. Interestingly, we found that endogenous JAB1 interacted with endogenous SOX9, a potent oncogene and a master regulator of skeletogenesis, in chondrosarcoma cells, but not in primary chondrocytes. JAB1 also binds to the same SOX9-mediated chondrocyte-specific enhancer elements in CS cells. Furthermore, we found that a recently developed, novel, potent, and JAB1-specific small molecule inhibitor, CSN5i-3, can significantly increase apoptosis, drastically alter the activities of several signaling pathways, and modulates the expression of specific Cullin-ring-ligases (CRLs) in CS cells. Finally, our RNA-sequencing analysis in JAB1-KD CS cells identified a total of 2945 differentially expressed genes. Gene set enrichment analysis revealed that JAB1 regulates several essential pathways such as DNA damage response and cell cycle regulation. In conclusion, our study showed that JAB1 might regulate a distinct pro-tumorigenic regulatory network to promote chondrosarcoma pathogenesis.

A system-level approach identifies HIF-2α as a critical regulator of chondrosarcoma progression

Chondrosarcomas, malignant cartilaginous neoplasms, are capable of transitioning to highly aggressive, metastatic, and treatment-refractory states, resulting in significant patient mortality. Here, we aim to uncover the transcriptional program directing such tumor progression in chondrosarcomas. We conduct weighted correlation network analysis to extract a characteristic gene module underlying chondrosarcoma malignancy. Hypoxia-inducible factor-2α (HIF-2α, encoded by EPAS1) is identified as an upstream regulator that governs the malignancy gene module. HIF-2α is upregulated in high-grade chondrosarcoma biopsies and EPAS1 gene amplification is associated with poor prognosis in chondrosarcoma patients. Using tumor xenograft mouse models, we demonstrate that HIF-2α confers chondrosarcomas the capacities required for tumor growth, local invasion, and metastasis. Meanwhile, pharmacological inhibition of HIF-2α, in conjunction with the chemotherapy agents, synergistically enhances chondrosarcoma cell apoptosis and abolishes malignant signatures of chondrosarcoma in mice. We expect that our insights into the pathogenesis of chondrosarcoma will provide guidelines for the development of molecular targeted therapeutics for chondrosarcoma.

Chondrosarcomas are frequently aggressive, understanding the transcriptional changes associated with progression may help in developing new treatments. Here, the authors show that HIF-2α is increased in expression on progression and pharmacological inhibition of the protein together with chemotherapy is a useful strategy for controlling tumour growth in mice.

Association of Preoperative Neutrophil/Lymphocyte Ratio with Clinical Outcomes in Dedifferentiated Chondrosarcoma Patients

Background

Dedifferentiated chondrosarcoma (DC) is an extremely uncommon malignant bone tumor with dismal survival outcomes. The purpose of this study was to investigate whether the preoperative neutrophil/lymphocyte ratio (NLR) has the ability to predict overall survival (OS) in DC patients.

Materials and Methods

Twenty-three DC patients with surgical resection were retrospectively reviewed between 2008 and 2015. The clinical pathological information and survival data were collected for analysis. The cut-off point for NLR was defined by receiver operating curve (ROC). The impact of NLR level on OS between two groups was compared using Kaplan–Meier curves with the Log-rank test. The association between NLR and OS was calculated by univariate and multivariate Cox proportional models.

Results

From the ROC analysis, the optimal NLR cut-off point was 3.11. Patients with high NLR had a worse OS than low NLR (p = 0.003, Log-rank test). In univariate analysis, a significant association was observed between high NLR and poor OS (Hazard ratio (HR) 4.62, 95% confidence interval (CI) 1.48–14.34, p = 0.008). After adjustment of co-variables, high NLR had more than 4 times the risk of mortality (HR 4.01, 95% CI 1.12–14.26, p = 0.032).

Conclusion

Preoperative NLR in peripheral blood is an easily accessible and cost-effective prognostic biomarker in DC patients. A prospective study with large sample size is warranted.

Risk Factors for Incidence and Prognosis in Chondrosarcoma Patients with Pulmonary Metastasis at Initial Diagnosis

Background

The incidence and prognostic factors of chondrosarcoma patients have been reported in early studies. However, the association between risk factors and the incidence or prognosis of chondrosarcoma patients with pulmonary metastasis remains unclear. Therefore, we assessed these risk factors among chondrosarcoma patients with pulmonary metastasis.

Material/Methods

From 1365 chondrosarcoma patients in the Surveillance, Epidemiology, and End Results (SEER) database, we collected the information of 69 patients with pulmonary metastasis at the initial diagnosis of chondrosarcoma from 2010 to 2016. We investigated the incidence, risk factors, and prognostic factors for pulmonary metastasis patients by using multivariate logistic regression and multivariate Cox regression analyses.

Results

Data from a total of 69 (6.8%) chondrosarcoma patients with pulmonary metastasis at initial diagnosis were extracted. Patients with the following characteristics were positively associated with higher risk of pulmonary metastasis: dedifferentiated subtype, high grade of malignancy, extracompartmental tumor (Enneking B), presence of regional lymph nodes, local recurrence, large tumor size (larger than 15 cm), and being married. Older patients (older than 67 years), and patients with clear cell chondrosarcoma or large tumor size (larger than 15 cm) exhibited the worse prognosis and survival (overall and cancer-specific). Resection of the primary tumor tended to be correlated with a better prognosis.

Conclusions

The incidence of pulmonary metastasis in chondrosarcoma was approximately 6.8%, with poor prognosis. Identifying risk factors and their associations with the incidence and prognosis in chondrosarcoma patients with pulmonary metastasis could provide a reference for clinical surveillance and guide the design of personalized treatment plans.

Association of Mental Health-Related Proteins DAXX, DRD3, and DISC1 With the Progression and Prognosis of Chondrosarcoma

Chondrosarcoma is the second most common malignant bone tumor. Current therapies remain ineffective, resulting in poor prognoses. Biomarkers for chondrosarcoma and predictors of its prognosis have not been established. Mental health-related proteins have been associated with the pathogenesis, progression, and prognosis of many cancers, but their association with chondrosarcoma has not been reported. In this study, the expression and clinicopathological significance of the mental health-related proteins DAXX, DRD3, and DISC1 in chondrosarcoma tissue samples were examined, over an 84-months follow-up period. In immunohistochemical analysis, the rates of positive DAXX, DRD3, and DISC1 expression were significantly higher in chondrosarcoma than in osteochondroma tissue (P < 0.01). The percentages of positive DAXX, DRD3, and DISC1 expression were significantly lower in tissues with good differentiation (P < 0.01), AJCC stage I/ II (P < 0.01), Enneking stage I (P < 0.01), and non-metastasis (P < 0.05), respectively. In Kaplan-Meier survival analysis, significantly shorter mean survival times were associated with moderate and poor differentiation (P = 0.000), AJCC stage III/IV (P = 0.000), Enneking stage II/III (P = 0.000), metastasis (P = 0.019), invasion (P = 0.013), and positive DAXX (P = 0.012), and/or DRD3 (P = 0.018) expression. In Cox regression analysis, moderate and poor differentiation (P = 0.006), AJCC stage III/IV (P = 0.013), Enneking stage II/III (P = 0.016), metastasis (P = 0.033), invasion (P = 0.011), and positive DAXX (P = 0.033), and/or DRD3 (P = 0.025) staining correlated negatively with the postoperative survival rate and positively with mortality. In competing-risks regression analysis, differentiation (P = 0.005), metastasis (P = 0.014), invasion (P = 0.028), AJCC stage (P = 0.003), Enneking stage (P = 0.036), and DAXX (P = 0.039), and DRD3(P = 0.019) expression were independent predictors of death from chondrosarcoma. The areas under receiver operating characteristic curves for DAXX, DRD3, and DISC1 expression were 0.673 (95% CI, 0.557-0.788; P = 0.010), 0.670 (95% CI, 0.556-0.784; P = 0.011), and 0.688 (95% CI, 0.573-0.802; P = 0.005), respectively. These results suggest that DAXX, DRD3, and DISC1 could serve as biomarkers of chondrosarcoma progression and predictors of its prognosis.

Dedifferentiated chondrosarcoma: Radiological features, prognostic factors and survival statistics in 23 patients

Background

Dedifferentiated chondrosarcoma is a rare, highly malignant tumor with a poor survival. There are many confusing issues concerning the imaging feature that can facilitate early diagnosis and the factors that might be related to outcomes.

Methods

Twenty-three patients with dedifferentiated chondrosarcoma confirmed by pathology were retrospectively reviewed from 2008 to 2015. The patients’ clinical information, images from radiographs (n = 17), CT (n = 19), and MRI (n = 17), histological features, treatment and prognosis were analyzed.

Results

There were 12 males and 11 females, and the mean age was 50.39 years old. Fourteen cases affected the axial bone (pelvis, spine), and 9 cases involved the appendicular bone. Seven (41.17%), 9 (47.36), and 12 (66.66%) lesions showed a biphasic nature on radiograph, CT and MRI, respectively. Of the lesions, 17.39% (4/23) were accompanied by pathological fractures. Histologically, the cartilage component was considered histological Grade1 in 12 patients and Grade 2 in 11 patients. The dedifferentiated component showed features of osteosarcoma in 8 cases, malignant fibrous histiocytoma in3 cases, myofibroblastic sarcoma in 1 case and spindle cell sarcoma in 11cases. Twenty-two cases were treated with surgical resection, and 17 cases achieved adequate (wide or radical) surgical margin. In 8 cases, surgery was combined with adjuvant chemotherapy. The overall median survival time was nine months; 17.4% of patients survived to five years.

Conclusion

Axial bone location, lung metastasis at diagnosis, inadequate surgical margin, incorrect diagnosis before surgery and pathological fractures was related to poorer outcome. Pre- or postoperative chemotherapy had no definitively effect on improved survival.

Microarray based analysis of gene regulation by mesenchymal stem cells in breast cancer

Breast cancer is one of the most common malignant tumors with a high case-fatality rate among women. The present study aimed to investigate the effects of mesenchymal stem cells (MSCs) on breast cancer by exploring the potential underlying molecular mechanisms. The expression profile of GSE43306, which refers to MDA-MB-231 cells with or without a 1:1 ratio of MSCs, was downloaded from Gene Expression Omnibus database for differentially expressed gene (DEG) screening. The Database for Annotation, Visualization and Integrated Discovery was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs. The protein-protein interactional (PPI) network of DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins. The data was subsequently analyzed using molecular complex detection for sub-network mining of modules. Finally, DEGs in modules were analyzed using GO and KEGG pathway enrichment analyses. A total of 291 DEGs including 193 upregulated and 98 downregulated DEGs were obtained. Upregulated DEGs were primarily enriched in pathways including response to wounding (P=5.92×10^-7), inflammatory response (P=5.92×10^-4) and defense response (P=1.20×10^-2), whereas downregulated DEGs were enriched in pathways including the cell cycle (P=7.13×10^-4), mitotic cell cycle (P=6.81×10^-3) and M phase (P=1.72 ×10^-2). The PPI network, which contained 156 nodes and 289 edges, was constructed, and Fos was the hub node with the degree of 29. A total of 3 modules were mined from the PPI network. In total, 14 DEGs in module A were primarily enriched in GO terms, including response to wounding (P=4.77×10^-6), wounding healing (P=6.25×10^-7) and coagulation (P=1.13 ×10^-7), and these DEGs were also enriched in 1 KEGG pathway (complement and coagulation cascades; P=0.0036). Therefore, MSCs were demonstrated to exhibit potentially beneficial effects for breast cancer therapy. In addition, the screened DEGs, particularly in PPI network modules, including FN1, CD44, NGF, SERPINE1 and CCNA2, may be the potential target genes of MSC therapy for breast cancer.

Pulmonary Metastases Exhibit Epigenetic Clonality: Implications for Precision Cancer Therapy

BACKGROUND

Development of effective cancer therapies may be limited by intratumoral heterogeneity, which facilitates outgrowth and organ-specific dissemination of treatment resistant clones. At present, limited information is available regarding epigenetic landscapes of pulmonary metastases. This study was undertaken to characterize epigenetic signatures of pulmonary metastases and to identify potential therapeutic targets.

METHODS

RNA and DNA were extracted from 65 pulmonary metastases resected from 12 patients (5 with sarcoma, 7 with adrenocortical carcinoma). Quantitative reverse transcription polymerase chain reaction techniques were used to evaluate expression levels of cancer-testis (CT) genes (NY-ESO-1, MAGE-A3, MAGE-A9, MAGE-A12, GAGE1, CT-45, SSX-1, and SSX-2), tumor suppressor (TS) genes (p16 and RASSF1A), and genes encoding epigenetic modifiers (DNMT1, DNMT3A, DNMT3B, EZH2, EED, and SUZ12), aberrantly expressed in human malignant diseases. Pyrosequencing techniques were used to quantitate DNA methylation levels in LINE1, NBL2, and D4Z4 repetitive sequences and promoter methylation status of differentially regulated genes. Results of these analyses were compared with a standardized panel of normal lung tissues.

RESULTS

Pulmonary metastases exhibited histologically related and patient-specific global DNA demethylation. Significant interpatient heterogeneity of gene expression was observed even among patients with similar tumor histologic features. Epigenetic signatures appeared consistent among metastases from the same patient, irrespective of the time of resection (synchronous/metachronous) or the anatomic location. EZH2, EED, and SUZ12 (core components of Polycomb repressive complex-2 [PRC-2]) were upregulated in the majority of metastases.

CONCLUSIONS

Pulmonary metastases exhibit patient-specific epigenetic clonality, which may be exploited for precision therapies targeting aberrant CT or TS gene expression. PRC-2 may be a shared target for epigenetic therapy of pulmonary metastases.

Does ifosfamide therapy improve survival of patients with dedifferentiated chondrosarcoma?

BACKGROUND

Dedifferentiated chondrosarcoma remains a significant therapeutic challenge. Studies performed to date have not identified efficacious chemotherapy regimens for this disease.

QUESTIONS/PURPOSES

We sought to (1) evaluate the disease-specific survival at 2 and 5 years of patients with dedifferentiated chondrosarcoma; (2) assess the prognostic variables (both patient- and treatment-related), including the use of chemotherapy with ifosfamide, that relate to survivorship; and (3) assess specific toxicities associated with ifosfamide use.

METHODS

Data from 41 patients with dedifferentiated chondrosarcoma diagnosed and treated at the University of Texas MD Anderson Cancer Center from 1986 to 2010 were analyzed for demographics, treatments, oncologic outcomes, and prognostic variables. There were 14 women and 27 men. The mean age at diagnosis was 58 years (range, 26-86 years). Seven patients presented with metastasis. Surgical resection alone was performed in 11 patients; resection and chemotherapy in 26 patients; resection and radiotherapy in two patients; and resection, chemotherapy, and radiotherapy in two patients. Ifosfamide-based regimens were used for 16 patients. In general, ifosfamide was used when the tumor was located in the trunk or if cisplatin was discontinued as a result of toxicity. Minimum followup was 8 months (median, 68 months; range, 8-281 months). Survival was estimated using Kaplan-Meier plots and analyzed by using the Cox proportional hazards model.

RESULTS

Disease-specific survival rates at 2 and 5 years were 33% and 15%, respectively. Multivariate analysis revealed that treatment without ifosfamide-based chemotherapy was the only independent negative prognostic factor for disease-specific survival (hazard ratio, 0.4; 95% confidence interval, 0.17-0.92; p = 0.03). Ifosfamide was discontinued in a patient as a result of renal dysfunction and was decreased in dose in another patient who developed encephalopathy.

CONCLUSIONS

In this small retrospective study, it appeared that ifosfamide-based adjuvant chemotherapy combined with surgical resection offered a treatment advantage compared with patients who did not receive the drug in patients with dedifferentiated chondrosarcoma, although disease-specific survival for patients who have this rare tumor remains dismal.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Dedifferentiated chondrosarcoma of the cervical spine: a case report

Dedifferentiated chondrosarcoma (DDCS) is a rare and aggressive bone tumor with poor prognosis. Primary DDCS of the mobile spine is extremely rare, particularly in the cervical spine. We herein describe a first case of cervical DDCS in an 81-year-old male presenting with a slowly growing mass. Radiographs showed an expansion of the cortical contour of the C2 lamina and a soft tissue mass with punctate calcification. Magnetic resonance imaging demonstrated a lobulated lesion expanding over the entire lamina and pedicles of C2 with the tumor protuberant to the adjacent soft tissue. A complete tumor resection was performed. Histologically, the majority of the tumor was a low-grade chondrosarcoma component. However, atypical spindle cells that had proliferated in a fascicular pattern with a collagenous stroma, mimicking fibrosarcoma, were focally observed without a transitional zone, and these features confirmed that the tumor was DDCS.