Real-word experience of pazopanib and sorafenib in patients with desmoid tumors: A CanSaRCC multi-center study.

BACKGROUND: Sorafenib and pazopanib, two tyrosine kinase inhibitors (TKI), are widely used in patients with progressive symptomatic desmoid tumors (DT). Limited real-word data is available on long-term outcomes of patients who progressed on, stopped, or continued TKIs. METHODS: Patients diagnosed with DTs and treated with sorafenib or pazopanib between 2011 and 2022 at 11 institutions were reviewed. Patient history, response to therapy and toxicity were recorded. Statistical analyses utilized Kaplan-Meier and log-rank tests. RESULTS: 142 patients with DT treated with sorafenib (n = 126, 88.7 %) or pazopanib (n = 16, 11.3 %) were analyzed. The median treatment duration was 10.8 months (range: 0.07- 73.9). The overall response rate and the disease control rate were 26.0 % and 95.1 %, respectively. The median tumor shrinkage was - 8.5 % (range -100.0 %- +72.5 %). Among responders, the median time to an objective response was 15.2 months (range: 1.1 to 33.1). The 1-year and 2-year progression-free survival rates were 82 % and 80 %. Dose reductions were necessary in 34 (23.9 %) patients. Grade 3 or higher adverse events were reported in 36 (25.4 %) patients. On the last follow-up, 55 (38.7 %) patients continued treatment. Treatment discontinuation (n = 85, 59.9 %) was mainly for toxicity (n = 35, 45.9 %) or radiological or clinical progression (n = 30, 35.3 %). For the entire cohort, 36 (25.4 %) patients required subsequent treatment. In the 32 responders, only 1 (3.1 %) patient required a subsequent treatment. In patients who discontinued TKI, 25 (44.6 %) with stable disease received subsequent treatment compared to 0 (0.0 %) of responders. CONCLUSION: This retrospective study represents the largest cohort of DT patients treated with sorafenib or pazopanib to date. Discontinuation of treatment in responders is safe. The optimal treatment duration in patients with stable disease remains to be defined.

Real-world experience of tyrosine kinase inhibitors in children, adolescents and adults with relapsed or refractory bone tumours: A Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) study.

OBJECTIVES: We conducted a retrospective multi-centre study to assess the real-world outcome of regorafenib (REGO) and cabozantinib (CABO) in recurrent/refractory bone tumours (BTs) including osteosarcoma (OST), Ewing sarcoma (EWS) and chondrosarcoma (CS)/extra-skeletal mesenchymal CS (ESMC). METHODS: After regulatory approval, data from patients with recurrent BT (11 institutions) were extracted from CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration) database. Patient characteristics, treatment and outcomes were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. RESULTS: From July 2018 to May 2022, 66 patients received REGO or CABO; 39 OST, 18 EWS, 4 CS and 5 ESMC. Median age was 27.8 years (range 12-76); median starting dose was 60 mg for CABO (n = 37, range 40-60) and 120 mg for REGO (n = 29, range 40-160). Twenty-eight (42.4%) patients required dose reduction: hand-foot syndrome 7 (10.6%), nausea/vomiting 1 (1.5%), diarrhoea 1 (1.5%), 2 elevated LFTs (3%), elevated bilirubin 1 (1.5%) and mucositis 1 (1.5%). The median OS for patients with OST, EWS, CS and ESMC was 8.5 months (n = 39, 95% CI 7-13.1); 13.4 months (n = 18, 95% CI 3.4-27.2), 8.1 (n = 4, 95% CI 4.1-9.3) and 18.2 (n = 5, 95% CI (10.4-na), respectively. Median PFS for OST, EWS, CS and ECMS was 3.5 (n = 39, 95% CI 2.8-5), 3.9 (n = 18, 95% CI 2.1-5.9), 5.53 (n = 4. 95% CI 2.13-NA) and 11.4 (n = 5, 95% CI 1.83-14.7), respectively. Age, line of therapy, REGO versus CABO, or time from diagnosis to initiation of TKI were not associated with PFS on univariable analysis. CONCLUSION: Our real-world data show that TKIs have meaningful activity in recurrent BT with acceptable toxicities when started at modified dosing. Inclusion of TKIs in earlier lines of treatment and/or maintenance therapy could be questions for future research.

Cytokine profiling, pretreatment with anakinra, and tolerance development in platinum-induced mixed hypersensitivity reactions.

BACKGROUND: Cytokine-release reactions (CRR) induced by platinum-based chemotherapy, manifesting with fever, chills, and rigors, are poorly understood and not easily prevented by usual premedication or desensitization. OBJECTIVE: To gain a better understanding of platinum-induced CRR and to explore the use of anakinra as a tool to prevent its clinical manifestations. METHODS: A cytokine and chemokine panel was obtained before and after platinum infusion in 3 cases with a mixed (immunoglobulin E-mediated and CRR) platinum-induced hypersensitivity reaction and in 5 controls either tolerant or with an immunoglobulin E-mediated platinum-induced hypersensitivity reaction. Anakinra was given as premedication in the 3 CRR cases. RESULTS: Cytokine-release reaction was associated with a marked release of interleukin (IL)-2, IL-5, IL-6, IL-10, and tumor necrosis factor-ɑ in all cases whereas only IL-2 and IL-10 increased in some controls after platinum infusion, and to a lesser extent than in cases. Anakinra seemed to block CRR symptoms in 2 cases. In the third case, who initially had CRR symptoms despite anakinra, tolerance to oxaliplatin appeared to develop after repeated re-exposures, as suggested by the decreasing levels of cytokines after oxaliplatin, except IL-10, and the capacity to progressively shorten the desensitization protocol and taper the premedication, in addition to the negativization of the oxaliplatin skin test result. CONCLUSION: In patients with platinum-induced CRR, anakinra could be a useful premedication to block its clinical manifestations, and monitoring of IL-2, IL-5, IL-6, IL-10, and tumor necrosis factor-ɑ could help predict tolerance development, thereby allowing safe adjustments to the desensitization protocol and premedication.

The Effect of Radiation and Chemoradiation Therapy on the Head and Neck Mucosal Microbiome: A Review.

Radiation (RT) and chemoradiation therapy (CRT) play an essential role in head and neck cancer treatment. However, both cause numerous side effects in the oral cavity, paranasal sinuses, and pharynx, having deleterious consequences on patients' quality of life. Concomitant with significant advances in radiation oncology, much attention has turned to understanding the role of the microbiome in the pathogenesis of treatment-induced tissue toxicity, to ultimately explore microbiome manipulation as a therapeutic intervention. This review sought to discuss current publications investigating the impact of RT and CRT-induced changes on the head and neck microbiome, using culture-independent molecular methods, and propose opportunities for future directions. Based on 13 studies derived from a MEDLINE, EMBASE, and Web of Science search on November 7, 2021, use of molecular methods has uncovered various phyla and genera in the head and neck microbiome, particularly the oral microbiome, not previously known using culture-based methods. However, limited research has investigated the impact of RT/CRT on subsites other than the oral cavity and none of the studies aimed to examine the relationship between the head and neck microbiome and treatment effectiveness. Findings from this review provide helpful insights on our current understanding of treatment-induced oral mucositis, dental plaque, and caries formation and highlight the need for future research to examine the effect of RT/CRT on the sinonasal and oropharyngeal microbiome. In addition, future research should use larger cohorts, examine the impact of the microbiome on treatment response, and study the effect of manipulating the microbiome to overcome therapy resistance.

Canadian consensus on TRK-inhibitor therapy for NTRK fusion-positive sarcoma.

Malignant sarcomas are rare accounting for <1% of all adult solid malignancies and approximately 11% to 13% of all pediatric malignancies. TRK-inhibitors have demonstrated robust and long-lasting responses in patients with NTRK fusion-positive solid tumors, including sarcoma. Access to these agents in many jurisdictions such as Canada remains limited. We undertook a modified Delphi consensus to articulate and convey the clinical importance of these agents for the Canadian sarcoma community. A systematic search of published and presented literature was conducted to identify clinical trials reporting outcomes on the use of TRK-inhibitors in relapsed/refractory NTRK fusion-positive sarcoma. Three main consensus questions were identified: (a) is there currently an unmet clinical need for systemic therapy options in relapsed/refractory sarcoma? (b) do TRK-inhibitors confer a clinical benefit to patients with NTRK fusion-positive sarcoma? (c) do phase I/II basket trials provide sufficient evidence to justify funding of TRK-inhibitors in NTRK fusion-positive sarcoma? Response rates to the first and second surveys were 57% (n = 30) and 42% (n = 22), respectively. There was strong agreement among the Canadian sarcoma community that there was unmet clinical need for effective systemic therapy options in relapsed/refractory sarcoma, that TRK-inhibitors are a safe and effective treatment option for patients with NTRK fusion-positive sarcoma, and that available phase I/II basket trials provide sufficient evidence to support funding of these agents in relapsed/refractory NTRK fusion-positive sarcoma. TRK-inhibitors are a safe and effective systemic therapy option for patients with relapsed/refractory NTRK fusion-positive sarcoma.

Canadian Consensus for Biomarker Testing and Treatment of TRK Fusion Cancer in Adults.

The tyrosine receptor kinase (TRK) inhibitors larotrectinib and entrectinib were recently approved in Canada for the treatment of solid tumours harbouring neurotrophic tyrosine receptor kinase (NTRK) gene fusions. These NTRK gene fusions are oncogenic drivers found in most tumour types at a low frequency (<5%), and at a higher frequency (>80%) in a small number of rare tumours (e.g., secretory carcinoma of the salivary gland and of the breast). They are generally mutually exclusive of other common oncogenic drivers. Larotrectinib and entrectinib have demonstrated impressive overall response rates and tolerability in Phase I/II trials in patients with TRK fusion cancer with no other effective treatment options. Given the low frequency of TRK fusion cancer and the heterogeneous molecular testing landscape in Canada, identifying and optimally managing such patients represents a new challenge. We provide a Canadian consensus on when and how to test for NTRK gene fusions and when to consider treatment with a TRK inhibitor. We focus on five tumour types: thyroid carcinoma, colorectal carcinoma, non-small cell lung carcinoma, soft tissue sarcoma, and salivary gland carcinoma. Based on the probability of the tumour harbouring an NTRK gene fusion, we also suggest a tumour-agnostic consensus for NTRK gene fusion testing and treatment. We recommend considering a TRK inhibitor in all patients with TRK fusion cancer with no other effective treatment options.

Gynecological Sarcomas: Molecular Characteristics, Behavior, and Histology-Driven Therapy.

Gynecological sarcomas represent 3% to 4% of all gynecological malignancies and 13% of all sarcomas. The uterus is the most frequent primary site (83%); less frequently sarcomas are diagnosed originating from the ovary (8%), vulva and vagina (5%), and other gynecologic organs (2%). As the classification of gynecologic sarcomas continues to diversify, so does the management. Accurate histopathologic diagnosis, utilizing appropriate ancillary immunohistochemical and molecular analysis, could lead to a more personalized approach. However, there are subtypes that require further definition, with regard to putative predictive markers and optimal management. The aim of this review is to highlight the importance of accurate diagnosis and classification of gynecologic sarcoma subtypes by the surgical pathologist in order to provide more tailored systemic treatment, and to highlight the increasing importance of close collaboration between the pathologist and the oncologist.

Adult soft tissue myoepithelial carcinoma: treatment outcomes and efficacy of chemotherapy.

Soft tissue myoepithelial carcinomas are a rare, malignant subgroup of myoepithelial tumours mostly arising in the extremities with equal predilection for women and men. The mainstay of management of localised disease is complete surgical resection. Despite optimal treatment, 40-45% of tumours recur. Data regarding the efficacy of systemic therapy for advanced and metastatic disease are lacking. The primary aim of this study was to evaluate the outcome of all patients with soft tissue myoepithelial carcinoma treated at a single referral centre. The secondary aim was to establish the efficacy of systemic therapies in patients with advanced disease. A retrospective review of the prospectively maintained Royal Marsden Sarcoma Unit database was performed to identify soft tissue myoepithelial carcinoma patients treated between 1996 and 2019. Patient baseline characteristics and treatment history were recorded. Response to systemic therapy was evaluated using RECIST 1.1. We identified 24 patients treated at our institution between 1996 and 2019,12 males and 12 females. Median age at presentation was 49.6 years [interquartile range (IQR) 40.5-63.3 years]. Twenty-two out of 24 patients (91.7%) underwent primary surgical resection. Nine patients (37.5%) received systemic treatment. A partial response was documented in one patient treated with doxorubicin. The median progression-free survival for first-line chemotherapy was 9.3 months. Myoepithelial carcinoma frequently recurs after complete surgical resection. Conventional chemotherapy demonstrated some activity in myoepithelial carcinoma, however, more effective systemic therapies are required and enrolment in clinical trial should be encouraged.

Probabilistic modeling of personalized drug combinations from integrated chemical screen and molecular data in sarcoma.

BACKGROUND: Cancer patients with advanced disease routinely exhaust available clinical regimens and lack actionable genomic medicine results, leaving a large patient population without effective treatments options when their disease inevitably progresses. To address the unmet clinical need for evidence-based therapy assignment when standard clinical approaches have failed, we have developed a probabilistic computational modeling approach which integrates molecular sequencing data with functional assay data to develop patient-specific combination cancer treatments. METHODS: Tissue taken from a murine model of alveolar rhabdomyosarcoma was used to perform single agent drug screening and DNA/RNA sequencing experiments; results integrated via our computational modeling approach identified a synergistic personalized two-drug combination. Cells derived from the primary murine tumor were allografted into mouse models and used to validate the personalized two-drug combination. Computational modeling of single agent drug screening and RNA sequencing of multiple heterogenous sites from a single patient's epithelioid sarcoma identified a personalized two-drug combination effective across all tumor regions. The heterogeneity-consensus combination was validated in a xenograft model derived from the patient's primary tumor. Cell cultures derived from human and canine undifferentiated pleomorphic sarcoma were assayed by drug screen; computational modeling identified a resistance-abrogating two-drug combination common to both cell cultures. This combination was validated in vitro via a cell regrowth assay. RESULTS: Our computational modeling approach addresses three major challenges in personalized cancer therapy: synergistic drug combination predictions (validated in vitro and in vivo in a genetically engineered murine cancer model), identification of unifying therapeutic targets to overcome intra-tumor heterogeneity (validated in vivo in a human cancer xenograft), and mitigation of cancer cell resistance and rewiring mechanisms (validated in vitro in a human and canine cancer model). CONCLUSIONS: These proof-of-concept studies support the use of an integrative functional approach to personalized combination therapy prediction for the population of high-risk cancer patients lacking viable clinical options and without actionable DNA sequencing-based therapy.

Clear Cell Sarcoma-like Tumor of the Gastrointestinal Tract: Clinical Outcome and Pathologic Features of a Molecularly Characterized Tertiary Center Case Series.

BACKGROUND/AIM: Clear cell sarcoma-like tumor of the gastrointestinal tract (CCSLTGT) is a very rare and relatively recently characterized mesenchymal neoplasm arising within the wall of the small bowel, stomach, or large bowel, predominantly in adolescents and young adults. Only few anecdotal reports or small series have been published and a consensus on treatment has not been formulated. Complete resection remains the only curative option for localized disease, but despite optimal surgery, CCSLTGT typically shows highly aggressive behavior with a high rate of local recurrence, metastases, and death from disease. The hallmark of CCSLTGT is the presence of EWSR1-CREB1 or EWSR1-ATF1 gene fusions, detectable with reverse transcription-polymerase chain reaction (PCR). The aim of this study was to assess all referred cases of CCSLTGT, and document the pathological features, treatment and outcome of these patients. PATIENTS AND METHODS: We retrospectively reviewed all cases of histologically- and molecularly-confirmed CCSLTGT with EWSR1-CREB1 or EWSR1-ATF1 fusions at our tertiary sarcoma center, between 2009 and 2016. RESULTS: We assessed six patients diagnosed with CCSLTGT. In a median follow-up of 8 months, all patients received surgery, and additionally one patient was treated with chemotherapy and had progressive disease. Five of six patients experienced recurrence or progression of disease and 4 of 6 patients died of disease. CONCLUSION: Our study confirms that CCSLTGT is a very rare aggressive sarcoma subtype with a very poor outcome. Greater international collaboration is required to obtain a better understanding of this disease.

Successful Ifosfamide Rechallenge in Soft-Tissue Sarcoma.

OBJECTIVES: Treatment options for metastatic soft-tissue sarcomas are limited. The aim of this study was to investigate the clinical activity of ifosfamide rechallenge in synovial sarcoma (SS), liposarcoma (LPS), leiomyosarcoma (LMS), and high-grade sarcomas not otherwise specified. METHODS: A retrospective search of the Royal Marsden Sarcoma Unit Database was performed to identify patients initially treated with ifosfamide (as single agent or in combination) and who were subsequently rechallenged with single-agent ifosfamide. Baseline demographics and response assessment were retrospectively obtained. RESULTS: Sixty-seven patients were identified and the median age at diagnosis was 41 years (range, 18 to 71 y). There were 29 cases of SS, 17 of LPS, 12 of LMS, and 9 of sarcomas not otherwise specified. First-line ifosfamide-containing therapy was given to 14 patients as adjuvant therapy (adjuvant group) and 53 patients as palliative therapy (palliative group). Clinical activity (partial response or stable disease) with single-agent ifosfamide rechallenge was documented in 50.0% of patients in the adjuvant group (7 in the second line) and 34.0% of patients in the palliative group (15 in the second line, 1 in third line, and 2 in the fourth line). The median progression-free survival in patients with documented clinical activity was 11.5 months (95% CI, 8.8-12.3) and 6.9 months (95% CI, 5.1-9.0), respectively, in the adjuvant and palliative group. Ifosfamide rechallenge was mostly active in SS patients (49.3%, 14 out of 29 patients with partial remission or stable disease). CONCLUSIONS: Ifosfamide rechallenge has clinical activity in soft-tissue sarcoma and can be considered a viable option in treating metastatic disease.

Eribulin in advanced liposarcoma and leiomyosarcoma.

INTRODUCTION: The heterogeneity of soft tissue sarcomas (STS) presents a formidable management challenge. Consequently, one of the main research goals is to define specific tailored therapy for each histological subtype and to develop a more personalised approach to treatment. The standard first line chemotherapy for advanced STS is doxorubicin, with or without ifosfamide, however, a number of different drugs are emerging as active therapies beyond first-line. Areas covered: Eribulin has recently been approved for advanced liposarcoma, after an anthracycline-containing regimen, demonstrating an overall survival (OS) advantage in liposarcoma and leiomyosarcoma in a randomised Phase III clinical trial. In this manuscript, an overview of the efficacy and safety of eribulin in STS is presented, highlighting different clinical outcomes between histological subtypes and comparing data with other effective drugs used in the treatment of sarcomas. The potential mechanisms of action of eribulin are also described, including its activity as potent microtubule-destabilizing anticancer agent, which has other antitumor biological effects. Expert commentary: Eribulin is highly effective in some STS populations and also has an acceptable toxicity profile. Further studies are required to better understand the precise mechanism of action of this agent and potential role in combination schedules.

Myoepithelial Carcinoma of the Paracecal Mesentery: Aggressive Behavior of a Rare Neoplasm at an Unusual Anatomic Site.

Myoepithelial tumors of the soft tissues represent a rare group of neoplasms that vary in their clinical behavior, pathologic features and genetics. They are histopathologically typified by a myoepithelial immunohistochemical phenotype, of expression of one or more epithelial markers, S100 protein and smooth muscle actin. Because of their rarity and occurrence over a wide age range and at a variety of anatomic sites, they can be difficult to diagnose due to the lack of familiarity by physicians, which is compounded by their spectrum of histologic features and morphologic overlap with several other neoplasms. Recent genetic insights have aided classification, and it is increasingly understood that soft tissue myoepithelial neoplasms can be stratified into two distinct morphologic and genetic subgroups. We describe a case of a 44-year-old man who was diagnosed with a primary myoepithelial neoplasm of the paracecal mesentery, which showed aggressive local recurrence after four years. The tumor was composed of cords of ovoid cells within chondromyxoid stroma, and displayed a characteristic pancytokeratin, S100 protein and smooth muscle actin-positive myoepithelial immunoprofile. Primary myoepithelioma has not been previously described at this site, and this case highlights this varied family of tumors, emphasizes the need to consider myoepithelial tumor in the differential diagnoses of carcinoma variants occurring in the bowel or mesentery, and also adds to the number of reported myoepithelial neoplasms showing markedly aggressive behavior.

The spectrum of EWSR1-rearranged neoplasms at a tertiary sarcoma centre; assessing 772 tumour specimens and the value of current ancillary molecular diagnostic modalities.

BACKGROUND: EWSR1 rearrangements were first identified in Ewing sarcoma, but the spectrum of EWSR1-rearranged neoplasms now includes many soft tissue tumour subtypes including desmoplastic small round cell tumour (DSRCT), myxoid liposarcoma (MLPS), extraskeletal myxoid chondrosarcoma (EMC), angiomatoid fibrous histiocytoma (AFH), clear cell sarcoma (CCS) and myoepithelial neoplasms. We analysed the spectrum of EWSR1-rearranged soft tissue neoplasms at our tertiary sarcoma centre, by assessing ancillary molecular diagnostic modalities identifying EWSR1-rearranged tumours and reviewing the results in light of our current knowledge of these and other Ewing sarcoma-like neoplasms. METHODS: We retrospectively analysed all specimens tested for EWSR1 rearrangements by fluorescence in situ hybridisation (FISH) and/or reverse transcription-PCR (RT-PCR) over a 7-year period. RESULTS: There was a total of 772 specimens. FISH was performed more often than RT-PCR (n=753, 97.5% vs n=445, 57.6%). In total, 210 (27.9%) specimens were FISH-positive for EWSR1 rearrangement compared to 111 (14.4%) that showed EWSR1 fusion transcripts with RT-PCR. Failure rates for FISH and RT-PCR were 2.5% and 18.0%. Of 109 round cell tumours with pathology consistent with Ewing sarcoma, 15 (13.8 %) cases were FISH-positive without an identifiable EWSR1 fusion transcript, 4 (3.7%) were FISH-negative but RT-PCR positive and 4 (3.7%) were negative for both. FISH positivity for DSRCT, MLPS, EMC, AFH and CCS was 86.3%, 4.3%, 58.5%, 60.0% and 87.9%, respectively. A positive FISH result led to diagnostic change in 40 (19.0%) EWSR1-rearranged cases. 13 FISH-positive cases remained unclassifiable. CONCLUSIONS: FISH is more sensitive for identifying EWSR1 rearrangements than RT-PCR. However, there can be significant morphologic and immunohistochemical overlap between groups of EWSR1-rearranged neoplasms, with important prognostic and therapeutic implications. FISH and RT-PCR should be used as complementary modalities in diagnosing EWSR1-rearranged neoplasms, but as tumour groups harbouring EWSR1 rearrangements are increasingly characterised and because given translocations involving EWSR1 and its partner genes are not always specific for tumour types, it is critical that these are evaluated by specialist soft tissue surgical pathologists noting the morphologic and immunohistochemical context. As RT-PCR using commercial primers is limited to only the most prevalent EWSR1 fusion transcripts, the incorporation of high-throughput sequencing technologies into the standard diagnostic repertoire to assess for multiple molecular abnormalities of soft tissue tumours in parallel (including detection of newly characterised Ewing sarcoma-like tumours) might be the most effective and efficient means of ancillary diagnosis in future.

Dermatofibrosarcoma protuberans: pathology, genetics, and potential therapeutic strategies.

Dermatofibrosarcoma protuberans (DFSP), the most common dermal sarcoma, is a malignant fibroblastic tumor most frequently arising in middle-aged adults. It is typically a low-grade sarcoma that grows slowly but has a high rate of local recurrence with low metastatic potential. Dermatofibrosarcoma protuberans is characterized by a specific translocation t(17;22)(q22;q13) leading to the formation of COL1A1-PDGFB fusion transcripts. Histologically, DFSP has characteristic morphology, of storiform islands of bland spindle cells, and immunohistochemically, it shows diffuse expression of CD34. However, the morphology and immunoprofile can overlap with a variety of other soft tissue neoplasms. The preferred management of localized disease is wide surgical resection or Mohs micrographic surgery, whereas radiotherapy may be used for margin-positive disease where reexcision is not possible, or for inoperable disease. Dermatofibrosarcoma protuberans is generally regarded as refractory to conventional chemotherapy. Treatment options for systemic disease have been previously limited, but the PDGFßR, KIT, and ABL inhibitor imatinib is now an option for effective systemic therapy. Continued insight into the tumorigenic molecular changes generated by the fusion oncogene may lead to further specific targeted treatments. We review DFSP, discussing the morphologic spectrum and variants, immunohistochemistry, molecular genetic findings, potential targeted treatments, and the differential diagnosis.

Efficacy and safety of eribulin mesylate in advanced soft tissue sarcomas.

Despite recent advances in the field, treatment options for metastatic soft tissue sarcoma patients are limited. Eribulin, an antimitotic derived from the natural marine sponge product halichondrin B, is currently approved for the treatment of metastatic breast cancer. Following the promising activity of eribulin in sarcoma in a Phase II trial, the drug was recently compared to dacarbazine in pretreated advanced leiomyosarcoma (LMS) and liposarcoma (LPS) patients in a Phase III trial. Eribulin was associated with a significant 2-month improvement in median overall survival compared to dacarbazine (13.5 vs. 11.5 months, heart rate: 0.768) despite no documented significant difference in progression-free survival. In a subgroup analysis, the survival advantage associated with eribulin was evident in the LPS subgroup but not in the LMS subgroup. Following these encouraging results, the Food and Drug Administration has approved eribulin for the treatment of advanced LPS for patients who received prior anthracycline chemotherapy. In this short review, we will evaluate the evidence for eribulin in soft tissue sarcoma, highlight its mechanisms of action, and summarize the results of the major preclinical and clinical studies with a particular focus on the results of the Phase III trial.

Rare Aggressive Behavior of MDM2-Amplified Retroperitoneal Dedifferentiated Liposarcoma, with Brain, Lung and Subcutaneous Metastases.

Dedifferentiated liposarcoma (DDL) is a histologically pleomorphic sarcoma, traditionally defined as well-differentiated liposarcoma with abrupt transition to high grade, non-lipogenic sarcoma. It can occur as part of recurrent well-differentiated liposarcoma, or may arise de novo. DDL most frequently occurs within the retroperitoneum, and while it is prone to local recurrence, it usually has a lower rate of metastasis than other pleomorphic sarcomas. We describe a case of retroperitoneal dedifferentiated liposarcoma in a 63-year-old male, who showed MDM2 amplification with fluorescence in situ hybridization, which displayed unusually aggressive behavior, with brain, lung and subcutaneous soft tissue metastases. As previous reports of metastatic liposarcoma have largely grouped DDL in with other (genetically and clinically distinct) liposarcoma subtypes, we highlight and discuss the rare occurrence of brain metastasis in MDM2-amplified retroperitoneal liposarcoma.

Desmoplastic Small Round Cell Tumor: Pathology, Genetics, and Potential Therapeutic Strategies.

Desmoplastic small round cell tumor (DSRCT) is an aggressive small round cell neoplasm which predominantly occurs intra-abdominally in adolescents and young adults with a male predominance, and which is characterized by a recurrent t(11;22)(p13;q12) translocation leading to formation of the EWSR1-WT1 fusion gene, which generates a chimeric protein with transcriptional regulatory activity. Histologically, DSRCT has a characteristic morphology, of islands of monotonous small cells within prominent sparsely cellular fibroblastic stroma, and immunohistochemically it shows polyphenotypic multidirectional differentiation, with expression of epithelial, muscle, and neural markers. However, DSRCT can arise more rarely in other sites and exhibit a spectrum of both histologic features and immunoprofile, which may confuse diagnosis with other small round cell neoplasms. Correct diagnosis is important to ensure correct treatment and prognostication; DSRCT are almost universally fatal neoplasms with patients usually succumbing to disease within the first 2 years of diagnosis. While combination treatment strategies can confer a survival benefit, the overall prognosis remains poor. Further insight into the tumorigenic molecular changes generated by the fusion oncogene may lead to the generation of specific targeted therapies. We review DSRCT, discussing morphology and immunohistochemistry, molecular genetic findings, potential targeted treatments, and the differential diagnosis.