COL1A1::PDGFB fusion-associated uterine fibrosarcoma: A case report and review of the literature.

BACKGROUND: Mesenchymal neoplasms of the uterus encompass a diverse group of tumors, with varying characteristics and origins, collectively accounting for 8% of uterine malignancies. The most common variants include uterine leiomyosarcoma, low-grade and high-grade endometrial stromal sarcoma, adenosarcoma, and undifferentiated sarcoma. Clinical presentation is often nonspecific and can lead to delayed diagnosis. Uterine sarcomas are generally aggressive, resulting in poorer prognosis compared to carcinomas. Recent advances in molecular techniques, such as next-generation sequencing (NGS), have led to the identification of new subtypes of uterine sarcomas, including COL1A1::PDGFB fusion-associated fibrosarcoma, which has a specific chromosomal translocation t(17;22)(q22;q13). Imatinib, a tyrosine kinase inhibitor (TKI), is an effective treatment for dermatofibrosarcoma protuberans (DFSP), marked by this translocation. CASE: We present the case of a 42-year-old woman diagnosed with COL1A1::PDGFB fusion-associated uterine fibrosarcoma. The patient underwent total hysterectomy and excision of the tumor, initially misdiagnosed as a low-grade leiomyosarcoma. Subsequent histological examination, immunohistochemistry, and fluorescence in situ hybridization (FISH) confirmed the diagnosis. After 10 months, disease recurrence was detected, and Imatinib therapy was initiated at a dose of 400 mg daily. An allergic reaction led to a temporary discontinuation, but upon resumption with appropriate medication, a positive radiological response was observed. The patient achieved a complete remission after 2 years and is still on Imatinib treatment. CONCLUSIONS: COL1A1::PDGFB fusion-associated uterine fibrosarcoma is an extremely rare mesenchymal neoplasm. In a case we present herein, we treated a patient with imatinib as first-line medical therapy. The patient is currently in complete remission after 37 months from treatment start. To the best of our knowledge, this represents a unique observation. We also provide a detailed literature review of the published cases so far. Prospective case series are needed to further understand the natural history of these tumors and optimize treatment strategies.

Neoadjuvant Chemotherapy in High-Grade Myxoid Liposarcoma: Results of the Expanded Cohort of a Randomized Trial From Italian (ISG), Spanish (GEIS), French (FSG), and Polish Sarcoma Groups (PSG).

PURPOSE: A randomized trial was conducted to compare neoadjuvant standard (S) anthracycline + ifosfamide (AI) regimen with histology-tailored (HT) regimen in selected localized high-risk soft tissue sarcoma (STS). The results of the trial demonstrated the superiority of S in all STS histologies except for high-grade myxoid liposarcoma (HG-MLPS) where S and HT appeared to be equivalent. To further evaluate the noninferiority of HT compared with S, the HG-MLPS cohort was expanded. PATIENTS AND METHODS: Patients had localized high-grade (cellular component >5%; size ≥5 cm; deeply seated) MLPS of extremities or trunk wall. The primary end point was disease-free survival (DFS). The secondary end point was overall survival (OS). The trial used a noninferiority Bayesian design, wherein HT would be considered not inferior to S if the posterior probability of the true hazard ratio (HR) being >1.25 was <5%. RESULTS: From May 2011 to June 2020, 101 patients with HG-MLPS were randomly assigned, 45 to the HT arm and 56 to the S arm. The median follow-up was 66 months (IQR, 37-89). Median size was 107 mm (IQR, 84-143), 106 mm (IQR, 75-135) in the HT arm and 108 mm (IQR, 86-150) in the S arm. At 60 months, the DFS and OS probabilities were 0.86 and 0.73 (HR, 0.60 [95% CI, 0.24 to 1.46]; log-rank P = .26 for DFS) and 0.88 and 0.90 (HR, 1.20 [95% CI, 0.37 to 3.93]; log-rank P = .77 for OS) in the HT and S arms, respectively. The posterior probability of HR being >1.25 for DFS met the Bayesian monitoring cutoff of <5% (4.93%). This result confirmed the noninferiority of trabectedin to AI suggested in the original study cohort. CONCLUSION: Trabectedin may be an alternative to standard AI in HG-MLPS of the extremities or trunk when neoadjuvant treatment is a consideration.

Deciding individual treatment for primary retroperitoneal sarcoma.

INTRODUCTION: Retroperitoneal sarcomas (RPS) are rare mesenchymal tumors that account for only 0.1-0.2% of all malignancies. Management of this disease is challenging, and resection remains the cornerstone of treatment. Ongoing international collaboration has expanded our knowledge of this disease, allowing for a more personalized approach to RPS patients resulting in improved survival over time. Due to the heterogeneity of RPS, with differing recurrence patterns and sensitivities to neoadjuvant therapies based on histology and grade, management of RPS should be tailored to the individual patient. AREAS COVERED: Our review focuses on a histology-driven approach in the management of primary RPS. We searched relevant articles from 1993 to 2023 that investigated prognostic factors and treatment of patients with RPS and summarized recent advances and future directions in the field. EXPERT OPINION: Deeper understanding of the role of neoadjuvant radiotherapy and ongoing trials investigating the role of neoadjuvant chemotherapy will potentially contribute to the development of individualized treatment pathways.

Low-Grade Uterine Leiomyosarcoma Is Highly Sensitive to Hormonal Treatment.

PURPOSE: According to the World Health Organization classification system, uterine leiomyosarcomas (ULMS) are high-grade. A diagnosis of smooth-muscle tumors of uncertain malignant potential (STUMP) is made when Stanford Criteria for ULMS are not met. When a STUMP recurs, the tumor is diagnosed as ULMS and medical treatment is the same as for ULMS. In recent years, some sarcoma centers valued the less aggressive clinical behavior of several recurring STUMP and, given their expression of estrogen and progesterone receptors, started to treat them with hormonal therapy. EXPERIMENTAL DESIGN: This was a retrospective cohort analysis conducted at three referral centers joining the Leiomyosarcoma Foundation Roundtable. We selected all cases of uterine smooth muscle tumors consistent with STUMP and treated with hormonal therapy. RESULTS: 27 consecutive patients were identified. Median age at diagnosis was 43 years. Stage was IA-IB in more than 70% of patients. In these patients, median time to relapse was 62 months. Sites of first relapses were mostly pelvis and peritoneum (76%). After a median follow-up of 49 months, 14 patients (52%) had a partial response while 10 (37%) had a minor response or stable disease. Median time to progression was not reached. CONCLUSIONS: We observed a response or long-term stability rate on hormonal therapy in the 90% range; in all cases the time to relapse was significantly longer than in ULMS and in most cases the relapse was abdominal. On the basis of these findings, we conclude that a proportion of patients with uterine smooth muscle neoplasms actually present with a "low-grade ULMS."

Effectiveness and Safety of Trabectedin and Radiotherapy for Patients With Myxoid Liposarcoma: A Nonrandomized Clinical Trial.

Importance: Preclinical data about the synergistic activity of radiotherapy (RT) and trabectedin have been reported. The combination of trabectedin and RT in treating myxoid liposarcomas appears worth exploring. Objective: To explore the effectiveness and safety of trabectedin combined with RT. Design, Setting, and Participants: This international, open-label, phase 2 nonrandomized clinical trial including 46 patients with myxoid liposarcoma was conducted in 4 centers in Spain, 1 in Italy, and 2 in France from July 1, 2016, to September 30, 2019. Eligible patients had to have a histologic, centrally reviewed diagnosis of localized resectable myxoid liposarcoma arising from an extremity or the trunk wall. Interventions: Trabectedin was administered at the recommended dose stemming from the phase 1 trial (1.5 mg/m2), with intravenous infusion during 24 hours every 21 days for a total of 3 cycles. Radiotherapy was started after completion of the first trabectedin infusion (cycle 1, day 2). Patients received 25 fractions of radiation for a total of 45 Gy. Surgery was planned 3 to 4 weeks after the administration of the last preoperative cycle and not until 4 weeks after the end of preoperative RT. Pathologic specimens were mapped in tumor sections to estimate the histologic changes and the percentage of viable tumor after neoadjuvant treatment. Main Outcomes and Measures: The primary objective of the phase 2 part of the study was overall response. Secondary objectives were effectiveness measured by relapse-free survival and activity measured by functional imaging and pathologic response. Results: A total of 46 patients were enrolled. Four patients were not evaluable. The median age was 43 years (range, 18-77 years), and 31 patients were male (67%). Overall, 9 of 41 patients (22%) achieved a partial response with neoadjuvant treatment with trabectedin and RT, with 5 of 39 patients (13%) achieving a complete pathologic response and 20 of 39 patients (51%) having 10% or less of a viable remaining tumor. Partial responses according to Choi criteria were observed in 24 of 29 evaluable patients (83%), and no patient had disease progression. Treatment was well tolerated. Conclusions and Relevance: Although the primary end point of this phase 2 nonrandomized clinical trial was not met (Response Evaluation Criteria in Solid Tumors response in ≥70% of patients), results suggest this combination was well tolerated and effective in terms of pathologic response. Thus, trabectedin plus RT might be a treatment option regarding tolerability; further evidence should be generated in this setting.

Trabectedin use in soft-tissue sarcoma patients in a real-world setting: Data from an Italian national drug-access registry.

Trabectedin is a marine-derived anticancer drug approved for the treatment of patients with advanced soft-tissue sarcomas (STS). Here, we aimed to analyze its use in a large cohort of STS patients treated in Italy in a real-world setting. Data on STS patients treated with trabectedin in Italy were prospectively collected from January 2013 to December 2019 by the national drug regulator, the Italian Medicines Agency (AIFA). Time-to-off-treatment (TToT) was defined as the time between the initial prescription of trabectedin and the date of treatment discontinuation for any cause. The impact of the different baseline covariates, including the initial prescribed dose of trabectedin, on TToT was evaluated using an accelerated failure time (AFT) models with log-logistic distribution. In total, we analyzed data from 2633 sarcoma patients and 14 950 individual cycles of trabectedin. The median number of cycles of trabectedin received per patient was 3 (interquartile range 2-7). The labeled 1.5 mg/sqm dose was used in 27.3% of all first prescriptions. Overall, the median TToT was 93 days. In the final AFT model, the variables significantly associated to longer TToT were female gender (+13% increase in TToT); ECOG performance status 0 (+50%); histological diagnosis of leiomyosarcoma (+22%), well-differentiated/dedifferentiated liposarcoma (+72%) or myxoid liposarcoma (+61%); receiving treatment in a high-volume center (+23%). In this large real-world cohort of STS patients treated with trabectedin, our findings support the use of trabectedin in STS patients, in particular in leiomyosarcoma and liposarcoma patients, and highlight the role of treatment center volume in their management.

Preoperative Neutrophil-to-Lymphocyte Ratio and a New Inflammatory Biomarkers Prognostic Index for Primary Retroperitoneal Sarcomas: Retrospective Monocentric Study.

PURPOSE: Inflammatory biomarkers and neutrophil-to-lymphocyte ratio (NLR) are associated with prognosis in several tumors. Data on sarcomas are limited, and insufficient on retroperitoneal sarcoma (RPS). EXPERIMENTAL DESIGN: Patients with primary RPS operated between 2002 and 2016 were included. Hemoglobin, monocytes, NLR, platelet-to-lymphocyte ratio (PLR) were retrieved and analyzed both individually and combined into a prognostic index (IBPI). Correlation with clinicopathologic variables was studied, as well as postoperative morbidity according to NLR and IBPI risk categories. The association between overall survival (OS) and biomarkers and, in addition, the 7-year Sarculator-predicted OS probability (pOS) was analyzed using univariable and multivariable Cox models. RESULTS: 423/463 patients had complete data. The median follow-up was 84 months. The median NLR was 3.3 (IQR, 2.4-4.7), with significant variation across histologies. NLR was the only biomarker that independently predicted OS (HR, 1.2; 95% CI, 1.03-1.40; P = 0.02). The IBPI showed good discrimination for subgroups at different OS (log-rank test P < 0.0001). The Cox model for pOS alone showed a 7-year index of prediction accuracy of 26.9, which increased to 29.5 when IBPI was added to pOS as a complementary prognostic tool. IBPI was also associated with the risk of serious infectious postoperative complications (P = 0.0094; noninfectious complications, P = 0.6463). CONCLUSIONS: NLR was an independent prognostic factor for OS in RPS. When combined into a prognostic index with hemoglobin, monocytes, and PLR, it serves as a readily available prognostic tool addressing tumor-related inflammation and helps in classifying RPS risk in addition to the Sarculator nomogram.

A Ten-Year Real-Life Experience with Pazopanib in Uterine Leyomiosarcoma in Two High-Specialized Centers in Italy: Effectiveness and Safety.

BACKGROUND: Uterine leiomyosarcoma (uLMS) is characterized by aggressive behavior associated with a high risk of relapse and mortality. Several therapeutic agents have been employed in the treatment of metastatic disease, with a poor objective response rate. Pazopanib, approved in 2012, is a multi-targeted, orally active small molecule that exerts its effects by inhibiting several tyrosine kinases. To date, poor research on real-life data has been conducted. We aimed to assess the effectiveness and safety of the drug in everyday clinical practice. METHODS: We present results of multicenter retrospective data on 38 patients with heavily pretreated metastatic uLMS who underwent oral pazopanib during their therapeutic journey. RESULTS: At a median follow-up of 8.6 months, the disease control rate was 55.2%, with 17% partial responses and 15 patients (39.5%) with stable disease. At a median follow-up of 8.6 months, median progression-free survival was 4 months, and median overall survival was 19.8 months. The most common grade 3 adverse events (AEs) drug-related were hepatic toxicities, diarrhea, hypertension, nausea, and vomiting (all of them with an incidence of 5% considering the whole study cohort). No grade 4 AEs occurred. CONCLUSIONS: Pazopanib in everyday clinical practice is safe and shows a good disease control rate with prolonged survival.

Long-term disease stability with bicalutamide in a man with aggressive angiomyxoma: case report and state of art.

Aggressive angiomyxoma (AA) is a rare mesenchymal neoplasm, which is commonly diagnosed in females and located in the perineal and pelvic region. Tissue specimens of AA patients often show positivity for estrogen (ER) and progesterone receptors (PgR), while some cases of androgen receptor (AR) positivity have been reported in males. When feasible, surgical excision represent the most effective treatment of AA; however, when experiencing advanced or recurrent disease, local disease control could be achieved with systemic hormonal treatment. To date, evidence regarding AA management in male patients is scarce, and only a few cases have been reported in literature. Hereby, we describe the case of a 59-year-old-man suffering from perineal AA with positivity for androgen receptors (AR) showing a long-lasting disease stability during the treatment with an AR-blocking drug (bicalutamide). A literature review regarding the state of art of AA management with a particular look to male patients is also provided.

Transcription regulators and ultra-rare and other rare translocation-related sarcomas treated with trabectedin: A proof of principle from a post-hoc analysis.

Background: Among sarcomas, which are rare cancers with an incidence of <6 per 100.000/year cases, ultra-rare sarcomas have an incidence of approximately ≤1/1,000,000/year cases and altogether account for ~20% of all soft tissue sarcomas (STS) and bone sarcomas. The Italian Sarcoma Group has recently performed a non-interventional, retrospective TrObs study with data from 512 anthracycline-pretreated patients with advanced multiple STS histologies and treated with trabectedin (Palmerini, Cancers 2021; ClinicalTrials.gov Identifier: NCT02793050). Methods: A post-hoc analysis of case series to evaluate the efficacy and safety of trabectedin on patients with ultra-rare and other rare translocation-related sarcomas included in TrObs study was performed. Main outcomes comprised investigator-assessed overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and safety. Results: Thirty-six patients (18 women) with ultra-rare and other rare sarcoma and a median age of 53.0 years (range: 22-81) were included. Most patients had solitary fibrous tumor (SFT; n=11) followed by epithelioid sarcoma (n=5), malignant peripheral nerve sheath tumor (MPNST; n=4), extraskeletal myxoid chondrosarcoma (EMC; n=3), desmoplastic small round cell tumor (DSRCT; n=3), and alveolar soft part sarcoma (ASPS), rhabdomyosarcoma and clear cell sarcoma (n=2 each). Thirty-five patients had metastatic disease and 23 patients received trabectedin as a second-line treatment. Among 35 patients evaluable for response, two patients with SFT and ASPS had a partial response and one patient with DSRCT obtained a complete response, reaching an ORR of 8.6% (95% CI: 2.8-23.4%). Among patients with an ORR, 6-months PFS was 100% in patients with ASPS, 45.7% in patients with SFT and 33.3% in those with DSRCT. Two patients with epithelioid sarcoma and myoepithelioma had disease stabilization lasting >24 months. Nine patients had at least one grade 3/4 adverse event, mostly being bone marrow toxicity (n=6). Conclusions: Trabectedin has some anti-tumor activity in some ultra-rare and other rare sarcomas, particularly translocation-related sarcomas, with the well-known manageable safety profile.

Activity of Cabazitaxel in Metastatic or Inoperable Locally Advanced Dedifferentiated Liposarcoma: A Phase 2 Study of the EORTC Soft Tissue and Bone Sarcoma Group (STBSG).

Importance: Treatment options for patients with unresectable and/or metastatic dedifferentiated liposarcoma (DDLPS) are limited. New drugs are required. Objective: To assess whether cabazitaxel demonstrated sufficient antitumor activity in patients with metastatic or inoperable locally advanced DDLPS to justify further investigation in a phase 3 setting. Design, Setting, and Participants: This international multicenter, open-label single-arm phase 2 trial was conducted at 10 institutions in 4 European countries from March 2015 to March 2019. Eligible patients had to have metastatic or locally advanced histologically proven DDLPS with evidence of disease progression within the past 6 months and had to have received no more than 1 previous line of chemotherapy. Interventions: After mandatory central review of tumor blocks, if the DDLPS diagnosis was confirmed, patients started treatment within 72 hours after registration. Cabazitaxel was administered at a dose of 25 mg/m2 IV infusion over 1 hour every 21 days until intolerance, progression, or withdrawal of consent. Main Outcomes and Measures: The primary end point was progression-free survival (PFS) rate at 12 weeks per RECIST 1.1. Based on a Simon 2-stage design, at least 4 of 17 (stage 1) and 11 of 37 (stage 2) eligible and evaluable patients who were progression free at 12 weeks were needed. The final analysis report was completed on November 17, 2021. Results: Forty patients were registered, with 2 patients being ineligible. The number of cycles ranged from 1 to 30, with a median of 5; 26 patients (65%) received at least 4 cycles of cabazitaxel. Progression-free survival at 12 weeks was 55%, achieving the primary study end point. At a median follow-up of 21.6 months, median PFS was 6 months and median OS 21 months. Response rate (RR) was 8% with 1 clinical response (CR) and 2 partial responses (PR). Twenty-three (60.5%) patients had a stable disease (SD). Disease control (PR+SD) was achieved in 26 patients (68%). Conclusions and Relevance: This nonrandomized phase 2 clinical trial met its primary end point, with 21 of 38 patients (55%) being progression free at 12 weeks. These results suggest important activity of cabazitaxel in patients with metastatic or inoperable locally advanced DDLPS. The drug is worth being further studied in these tumors in a phase 3 setting.

Retrospective observational studies in ultra-rare sarcomas: A consensus paper from the Connective Tissue Oncology Society (CTOS) community of experts on the minimum requirements for the evaluation of activity of systemic treatments.

BACKGROUND: In ultra-rare sarcomas (URS) the conduction of prospective, randomized trials is challenging. Data from retrospective observational studies (ROS) may represent the best evidence available. ROS implicit limitations led to poor acceptance by the scientific community and regulatory authorities. In this context, an expert panel from the Connective Tissue Oncology Society (CTOS), agreed on the need to establish a set of minimum requirements for conducting high-quality ROS on the activity of systemic therapies in URS. METHODS: Representatives from > 25 worldwide sarcoma reference centres met in November 2020 and identified a list of topics summarizing the main issues encountered in ROS on URS. An online survey on these topics was distributed to the panel; results were summarized by descriptive statistics and discussed during a second meeting (November 2021). RESULTS: Topics identified by the panel included the use of ROS results as external control data, the criteria for contributing centers selection, modalities for ensuring a correct pathological diagnosis and radiologic assessment, consistency of surveillance policies across centers, study end-points, risk of data duplication, results publication. Based on the answers to the survey (55 of 62 invited experts) and discussion the panel agreed on 18 statements summarizing principles of recommended practice. CONCLUSIONS: These recommendations will be disseminated by CTOS across the sarcoma community and incorporated in future ROS on URS, to maximize their quality and favor their use as control data when results from prospective studies are unavailable. These recommendations could help the optimal conduction of ROS also in other rare tumors.

Management of Locally Recurrent Retroperitoneal Sarcoma in the Adult: An Updated Consensus Approach from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group.

BACKGROUND: Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS. METHODS: An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor. RESULTS: Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS. CONCLUSIONS: Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

First-line chemotherapy in advanced intra-abdominal well-differentiated/dedifferentiated liposarcoma: An EORTC Soft Tissue and Bone Sarcoma Group retrospective analysis.

BACKGROUND: No prospective trial with anthracycline-based chemotherapy has individually assessed response in a well-differentiated (WD)/dedifferentiated (DD) liposarcoma patient cohort. We conducted a retrospective analysis of first-line chemotherapy in liposarcoma of intra-abdominal origin (IA-LPS) in patients who had entered the European Organisation for Research and Treatment of Cancer (EORTC)/Soft Tissue and Bone Sarcoma Group (STBSG) trials. METHODS: We searched for all adult patients treated with first-line chemotherapy for advanced IA-LPS in the EORTC STBSG phase 2 and 3 trials from 1978. Treatment was aggregated into 5 groups: anthracycline alone, ifosfamide alone, doxorubicin plus ifosfamide (D+IFO), doxorubicin/cyclophosphamide/vincristine/dacarbazine, and "other" (brostallicin, trabectedin). Response was assessed prospectively by Response Evaluation Criteria in Solid Tumors or World Health Organization criteria. Progression-free survival (PFS) and overall survival (OS) were computed by Kaplan-Meier method. RESULTS: A total of 109 patients with IA-LPS from 13 trials were identified (104 evaluable for response). Overall, there were 10/109 (9.2%) responders: 3/48 (6.3%) in the anthracycline alone group, 2/15 (13%) in the ifosfamide alone group, and 4/18 (22%) in the D+IFO group. At the 10-month median follow-up (interquartile range, 6-24), the median OS was 19 months (95% CI, 15-21) and median PFS 4 months (95% CI, 3-6). D+IFO achieved a not statistically significant longer median PFS (12 months) and median OS (31 months) than observed with other regimens. Univariate/multivariate analysis did not identify prognostic factors. CONCLUSIONS: Cytotoxic chemotherapy, in particular anthracycline alone, had marginal activity in advanced IA-LPS. Ifosfamide-containing regimens showed higher activity, although it was not statistically significant and in a small number of cases, with the combination of doxorubicin and ifosfamide appearing to be the more active regimen available in fit patients. This series provides a benchmark for future trials on new drugs in WD/DD liposarcoma.

Treatment strategies and outcomes of primary Myxofibrosarcomas in a large patients cohort.

BACKGROUND: this study analysed primary myxofibrosarcoma (MFS) to investigate patient outcomes focusing on histopathologic margins and perioperative treatments. PATIENTS AND METHODS: data from consecutive patients affected by primary and localized MFS of the extremities or trunk wall who underwent surgery (2002-2017) were analysed. Local recurrence (LR), amputation rate, incidence of distant metastasis (DM), and overall survival (OS) were studied. RESULTS: Of 293 included patients, 52 (17%) patients received perioperative treatments and 54 (18%) had positive microscopic histopathologic margins (R1). Median follow-up was 80 months (IQR, 49-109). 5-yr CCI of LR was 0.12 (SE: 0.02). Status of histopathologic margins (P < 0.001), tumour malignancy grade (P = 0.018) and size (P = 0023) were independent prognostic factor for LR. Nine amputations (amputation rate: 3%) were performed (N = 1 for primary tumour; N = 8 for LR). Larger tumour size (P = 0.015) and higher grade (P = 0.025) were independent prognostic factor for DM. 5-year OS was 0.84 (95%CI 0.79-0.88). Patient age (P = 0.008), tumour size (P = 0.013) and malignancy grade (P = 0.018) were independently associated to OS. In the subgroup of patients who had a re-excision for a primary MFS (N = 116, 40%), the presence of residual disease was not associated with LR, DM, or OS. CONCLUSION: in this study 5-year LR, DM and OS were 12%, 17%, and 84%, respectively. One in six patients had a positive surgical margin, which was a prognostic factor for LR, while DM and OS were predicted by tumour grade and size. Findings from this large patient cohort may set benchmarks for investigating new treatment options for MFS.

Oncological outcomes after major vascular resections for primary retroperitoneal liposarcoma.

BACKGROUND: The surgical management of retroperitoneal sarcomas frequently involves complex multivisceral resections, however retroperitoneal liposarcoma (LPS) rarely invade major abdominal vessels. The aim of the study was to assess association of major vascular resections with outcome of primary LPS. METHODS: All consecutive patients who underwent resection at our institutions for primary LPS between 2002 and 2019 were included. A propensity matched analysis was performed, adjusting the groups for the variables of Sarculator, to assess the effect of vascular resection on oncological outcomes. RESULTS: Overall 425 patients were identified. Twenty-four (5%) patients had vascular resection. At final pathology 18 patients had vascular infiltration, 2 vascular encasement and 4 involvement without infiltration. Vascular resection was associated with longer operative time (480' vs. 330'; p < 0.001) and greater need for transfusions (4 vs. 0 units; p < 0.001), and was burdened by a higher rate of major complications (54% vs. 25%; p = 0.002). After propensity matched analysis, patients undergoing vascular resection had a lower 5-year OS (60% vs. 81%; p = 0.05), and a higher incidence of local and distant recurrence at 5 years (local: 45% vs. 24%, p = 0.05; distant: 20% vs. 0%, p = 0.04). CONCLUSIONS: Vascular resection is feasible and safe even in the context of multivisceral resection for primary retroperitoneal liposarcomas, although associated to a higher complication rate. However, the independent association between vascular involvement and a higher risk of local recurrence, distant metastases and death may imply a more aggressive biology, which should be factored in the initial management of this complex disease.

Mechanisms of responsiveness to and resistance against trabectedin in murine models of human myxoid liposarcoma.

Myxoid liposarcoma (MLPS) is a rare soft-tissue sarcoma characterised by the expression of FUS-DDIT3 chimera. Trabectedin has shown significant clinical anti-tumour activity against MLPS. To characterise the molecular mechanism of trabectedin sensitivity and of resistance against it, we integrated genomic and transcriptomic data from treated mice bearing ML017 or ML017/ET, two patient-derived MLPS xenograft models, sensitive to and resistant against trabectedin, respectively. Longitudinal RNA-Seq analysis of ML017 showed that trabectedin acts mainly as a transcriptional regulator: 15 days after the third dose trabectedin modulates the transcription of 4883 genes involved in processes that sustain adipocyte differentiation. No such differences were observed in ML017/ET. Genomic analysis showed that prolonged treatment causes losses in 4p15.2, 4p16.3 and 17q21.3 cytobands leading to acquired-resistance against the drug. The results dissect the complex mechanism of action of trabectedin and provide the basis for novel combinatorial approaches for the treatment of MLPS that could overcome drug-resistance.

Trabectedin for Patients with Advanced Soft Tissue Sarcoma: A Non-Interventional, Retrospective, Multicenter Study of the Italian Sarcoma Group.

The Italian Sarcoma Group performed this retrospective analysis of patients with advanced soft tissue sarcoma, pretreated with ≥1 anthracycline-based treatment, and treated with trabectedin every three weeks. Primary endpoint was to describe real-life use of trabectedin across Italy. Secondary endpoints included objective response rate (ORR) and safety. Overall, 512 patients from 20 Italian centers were evaluated. Leiomyosarcoma (37.7%)/liposarcoma (30.3%) were the most prevalent histological types (abbreviated as L-sarcoma). Patients received a median of four trabectedin cycles (range: 1-40), mostly as a second-line treatment (~60% of patients). The ORR was 13.7% superior (p < 0.0001) in patients with L-sarcoma compared with patients with non-L-sarcoma (16.6% vs. 9.0%). Median progression-free survival (PFS) was 5.1 months, whereas median overall survival (OS) was 21.6 months. Significantly better PFS and OS were observed in patients with L-sarcoma, those with objective responses and/or disease stabilization, treated in an early line and treated with reduced dose. Bone marrow toxicity (61.4%) and transaminase increases (21.9%) were the most common grade 3/4 adverse events. The results of this real-life study suggest that trabectedin is an active treatment, which is mostly given as a second-line treatment to patients with a good performance status and high-grade, metastatic L-sarcoma (clinical trial information: NCT02793050).

Ultra-rare sarcomas: A consensus paper from the Connective Tissue Oncology Society community of experts on the incidence threshold and the list of entities.

BACKGROUND: Among sarcomas, which are rare cancers, many types are exceedingly rare; however, a definition of ultra-rare cancers has not been established. The problem of ultra-rare sarcomas is particularly relevant because they represent unique diseases, and their rarity poses major challenges for diagnosis, understanding disease biology, generating clinical evidence to support new drug development, and achieving formal authorization for novel therapies. METHODS: The Connective Tissue Oncology Society promoted a consensus effort in November 2019 to establish how to define ultra-rare sarcomas through expert consensus and epidemiologic data and to work out a comprehensive list of these diseases. The list of ultra-rare sarcomas was based on the 2020 World Health Organization classification, The incidence rates were estimated using the Information Network on Rare Cancers (RARECARENet) database and NETSARC (the French Sarcoma Network's clinical-pathologic registry). Incidence rates were further validated in collaboration with the Asian cancer registries of Japan, Korea, and Taiwan. RESULTS: It was agreed that the best criterion for a definition of ultra-rare sarcomas would be incidence. Ultra-rare sarcomas were defined as those with an incidence of approximately ≤1 per 1,000,000, to include those entities whose rarity renders them extremely difficult to conduct well powered, prospective clinical studies. On the basis of this threshold, a list of ultra-rare sarcomas was defined, which comprised 56 soft tissue sarcoma types and 21 bone sarcoma types. CONCLUSIONS: Altogether, the incidence of ultra-rare sarcomas accounts for roughly 20% of all soft tissue and bone sarcomas. This confirms that the challenges inherent in ultra-rare sarcomas affect large numbers of patients.