Randomised phase III trial of trabectedin versus doxorubicin-based chemotherapy as first-line therapy in translocation-related sarcomas

Beneficial Use of the Combination of Gemcitabine and Dacarbazine in Advanced Soft Tissue Sarcomas: Real-World Data

BACKGROUND

The combination of gemcitabine and dacarbazine has exhibited efficacy in terms of progression-free survival (PFS) and overall survival (OS) for aSTSs, albeit without robust confirmation from larger clinical trials.

METHODS

We conducted a retrospective study in a single institution involving aSTS patients treated with gemcitabine and dacarbazine.

RESULTS

95 patients were assessed, pointing to a benefit in PFS of 3.5 months and an OS of 14.2 months. Patients with translocated histotypes had better PFS, while those with platelet-lymphocyte ratios (PLRs) surpassing a specific threshold or lower albumin levels had poorer overall survival.

CONCLUSIONS

This study validates previous findings from three phase I-II trials, affirming the utility of this treatment approach in routine clinical practice.

Current topics and management of head and neck sarcomas

Given the low incidence, variety of histological types, and heterogeneous biological features of head and neck sarcomas, there is limited high-quality evidence available to head and neck oncologists. For resectable sarcomas, surgical resection followed by radiotherapy is the principle of local treatment, and perioperative chemotherapy is considered for chemotherapy-sensitive sarcomas. They often originate in anatomical border areas such as the skull base and mediastinum, and they require a multidisciplinary treatment approach considering functional and cosmetic impairment. Moreover, head and neck sarcomas may exhibit different behaviour and characteristics than sarcomas of other areas. In recent years, the molecular biological features of sarcomas have been used for the pathological diagnosis and development of novel agents. This review describes the historical background and recent topics that head and neck oncologists should know about this rare tumour from the following five perspectives: (i) epidemiology and general characteristics of head and neck sarcomas; (ii) changes in histopathological diagnosis in the genomic era; (iii) current standard treatment by histological type and clinical questions specific to head and neck; (iv) new drugs for advanced and metastatic soft tissue sarcomas; and (v) proton and carbon ion radiotherapy for head and neck sarcomas.

Chemotherapeutic drugs for soft tissue sarcomas: a review

Despite the low incidence of soft tissue sarcomas (STSs), hundreds of thousands of new STS cases are diagnosed annually worldwide, and approximately half of them eventually progress to advanced stages. Currently, chemotherapy is the first-line treatment for advanced STSs. There are difficulties in selecting appropriate drugs for multiline chemotherapy, or for combination treatment of different STS histological subtypes. In this study, we first comprehensively reviewed the efficacy of various chemotherapeutic drugs in the treatment of STSs, and then described the current status of sensitive drugs for different STS subtypes. anthracyclines are the most important systemic treatment for advanced STSs. Ifosfamide, trabectedin, gemcitabine, taxanes, dacarbazine, and eribulin exhibit certain activities in STSs. Vinca alkaloid agents (vindesine, vinblastine, vinorelbine, vincristine) have important therapeutic effects in specific STS subtypes, such as rhabdomyosarcoma and Ewing sarcoma family tumors, whereas their activity in other subtypes is weak. Other chemotherapeutic drugs (methotrexate, cisplatin, etoposide, pemetrexed) have weak efficacy in STSs and are rarely used. It is necessary to select specific second- or above-line chemotherapeutic drugs depending on the histological subtype. This review aims to provide a reference for the selection of chemotherapeutic drugs for multi-line therapy for patients with advanced STSs who have an increasingly long survival.

Clinical markers of immunotherapy outcomes in advanced sarcoma

BACKGROUND

Despite immunotherapy's promise in oncology, its use for sarcoma remains challenging. There are no sarcoma-specific biomarkers for immune checkpoint inhibitors (ICI). Previously, we reported our institutional experience highlighting ICI activity in 29 patients with sarcoma. In this study, we explore responses to ICI based on ICI regimen and other covariates to identify significant clinical factors in advanced sarcoma outcomes.

METHODS

Patients in The Ohio State University Sarcoma Clinics were enrolled in the Sarcoma Retrospective ICI database from January 1, 2015 through November 1, 2021. Data included treatment regimen (single-agent ICI or ICI + combination) along with clinical covariates. ICI + combination was further categorized into ICI + medication, ICI + radiation, ICI + surgery, or ICI + multiple (more than 2 modalities). Statistical analysis included log-rank tests and proportional hazard regression. The primary objective was to evaluate overall survival (OS) and progression-free survival (PFS).

RESULTS

Of the patients in the database, 135 met inclusion criteria. We demonstrated improved OS in patients treated with ICI + combination (p = 0.014, median 64 weeks), but no effect on PFS (p = 0.471, median 31 weeks). Patients with a documented immune-related adverse event (irAE) of dermatitis had improved OS, but only in the ICI + combination cohort (p = 0.021). Patients who received single-agent ICI and whose change in the neutrophil-to-lymphocyte ratio (NLR) was less than 5 had an improved OS (p = 0.002); this was not seen in patients who received ICI + combination therapy (p = 0.441). There were no differences in OS based on age, gender, histology, or subcategories of ICI + combination. This was not the case for PFS; patients who received any ICI regimen and were younger than 70 had a worse PFS (p = 0.036) compared with their older counterparts in this dataset. Patients who developed an irAE, specifically colitis (p = 0.009), hepatitis (p = 0.048), or dermatitis (p = 0.003), had an improved PFS. There were no differences in PFS based on ICI regimen (or subcategories of ICI + combination), gender, histology, change in NLR, or grade of irAE.

CONCLUSIONS

This retrospective study demonstrates that ICI + combination therapy can improve OS in some patients with advanced sarcoma. This is consistent with our prior results of ICI in sarcoma.

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.

Regorafenib for the Treatment of Sarcoma

OPINION STATEMENT

Sarcomas are a rare group of tumors with many subtypes, conventionally classified into soft-tissue sarcomas and bone sarcomas. Chemotherapeutic regimens form the mainstay of systemic therapy but are not well defined beyond the first-line setting and clinical outcomes are variable. Tyrosine kinase inhibitors (TKIs), with a broad inhibition profile which have been shown to target tumor angiogenesis, have an established role in the treatment of sarcomas without characteristic driver alterations. One such TKI, regorafenib, has been evaluated in sarcomas and clinical data are discussed in this review. An overview of regorafenib data from five phase 2 and one phase 1b clinical trials in over 10 sarcoma subtypes (both soft-tissue and bone) in adult and pediatric patients is reviewed. Regorafenib demonstrated clinical benefit in patients with non-adipocytic soft-tissue sarcomas, osteosarcoma and Ewing sarcoma who had progressed on prior therapy. Patients with otherwise limited treatment options may therefore benefit from regorafenib therapy.

New benchmarks to design clinical trials with advanced or metastatic liposarcoma or synovial sarcoma patients: An EORTC - Soft Tissue and Bone Sarcoma Group (STBSG) meta-analysis based on a literature review for soft-tissue sarcomas

BACKGROUND

Recently, we performed a meta-analysis based on a literature review for STS trials (published 2003-2018, ≥10 adult patients) to update long-standing reference values for leiomyosarcomas. This work is extended for liposarcomas (LPS) and synovial sarcomas (SS).

MATERIALS AND METHODS

Study endpoints were progression-free survival rates (PFSRs) at 3 and 6 months. Trial-specific estimates were pooled per treatment line (first-line or pre-treated) with random effects meta-analyses. The choice of the therapeutic benefit to target in future trials was guided by the European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS).

RESULTS

Information was acquired for 1030 LPS patients (25 trials; 7 first-line, 17 pre-treated, 1 both) and 348 SS patients (13 trials; 3 first-line, 10 pre-treated). For LPS, the overall pooled first-line PFSRs were 69% (95%-CI 60-77%) and 56% (95%-CI 45-67%) at 3 and 6 months, respectively. These rates were 49% (95%-CI 40-57%)/28% (95%-CI 22-34%) for >1 lines. For SS, first-line PFSRs were 74% (95%-CI 58-86%)/56% (95%-CI 31-78%) at 3 and 6 months, and pre-treated rates were 45% (95%-CI 34-57%)/25% (95%-CI 16-36%). Following ESMO-MCBS guidelines, the minimum values to target are 79% and 69% for first-line LPS (82% and 69% for SS) at 3 and 6 months. For pre-treated LPS, recommended PFSRs at 3 and 6 months suggesting drug activity are 63% and 44% (60% and 41% for SS).

CONCLUSIONS

New benchmarks are proposed for advanced/metastatic LPS or SS to design future histology-specific phase II trials. More data are needed to provide definitive thresholds for the different LPS subtypes.

Soft Tissue Sarcoma, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Soft tissue sarcomas (STS) are rare malignancies of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Soft Tissue Sarcoma provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as retroperitoneal/intra-abdominal STS, desmoid tumors, and rhabdomyosarcoma. This portion of the NCCN Guidelines discusses general principles for the diagnosis and treatment of retroperitoneal/intra-abdominal STS, outlines treatment recommendations, and reviews the evidence to support the guidelines recommendations.

Trabectedin in Cancers: Mechanisms and Clinical Applications

Trabectedin, a tetrahydroisoquinoline alkaloid, is the first marine antineoplastic agent approved with special anticancer mechanisms involving DNA binding, DNA repair pathways, transcription regulation and regulation of the tumor microenvironment. It has favorable clinical applications, especially for the treatment of patients with advanced soft tissue sarcoma, who failed in anthracyclines and ifosfamide therapy or could not receive these agents. Currently, trabectedin monotherapy regimen and regimens of combined therapy with other agents are both widely used for the treatment of malignancies, including soft tissue sarcomas, ovarian cancer, breast cancer, and non-small-cell lung cancer. In this review, we summarized the basic information and some updated knowledge on trabectedin, including its molecular structure, metabolism in various cancers, pharmaceutical mechanisms, clinical applications, drug combination, and adverse reactions, along with prospections on its possibly more optimal use in cancer treatment.

The Role of Trabectedin in Soft Tissue Sarcoma

Background: Systemic chemotherapy for advanced disease is another therapeutic option in the management of metastases in soft tissue sarcoma (STS). Doxorubicin either alone or in combination with ifosfamide has been used as first-line chemotherapy. Furthermore, in the past decade, new drugs have been shown to be effective in the treatment of advanced STS after the failure of first-line anthracycline-based chemotherapy: trabectedin, pazopanib and eribulin. However, the appropriate usage of these agents has not been established. Methods: We summarized clinical trials of trabectedin focusing on the efficacy and toxicity of trabectedin in the treatment of STS. Results: Trabectedin can be administered safely and effectively to the patients with advanced STS at second line setting or later. Although trabectedin may be effective as first-line treatment in selected patients, anthracycline-based chemotherapy should be recommended because no regimen in addition to trabectedin has proved to be unequivocally superior to doxorubicin as the first-line treatment for locally advanced or metastatic STS. Nucleotide excision repair (NER) and homologous recombination (HRe) repair may be of particular importance as efficacy of trabectedin. Conclusion: Trabectedin has shown a favorable toxicity profile and is an alternative therapeutic option in patients with advanced STS.

Trabectedin in Advanced Sarcomas-Experience at a Tertiary Care Center and Review of Literature

Background There is sparse literature on trabectedin in advanced soft-tissue sarcomas from developing world. It would be interesting to know about use and outcomes of trabectedin in Indian patients.

Method In a retrospective study, consecutive patients treated with trabectedin from 2016 to 2019 were analyzed. Patients with L-sarcomas were treated at a dose of 1.5 mg/m ² , while those with translocation-related sarcomas were treated at a dose of 1.2 mg/m ² as a 24-hour infusion through peripherally inserted central catheter line. From July 2019, infusions were administered through an ambulatory elastomeric pump, while before that patients were admitted for 24 hours. We used SPSS version 23.0 for statistical calculation.

Result A total of 20 patients received trabectedin with a total of 116 infusions. The median age was 46 years (range: 22–73 years). The male ( n = 11, 55%) and female patients were almost equal ( n = 9, 45%). Thirteen patients (65%) had Eastern Cooperative Oncology Group Performance Status 1. Majority of the patients had leiomyosarcoma ( n = 8, 40%); remaining comprised of liposarcoma (3, 15%), translocation-related sarcomas excluding myxoid liposarcoma ( n = 8, 40%) and others ( n = 1,5%). Most common site was extremity ( n = 11, 55%) followed by retroperitoneal ( n = 3, 15%), visceral ( n = 3, 15%), and others ( n = 3,15%). Median number of previous lines received was 2 (range: 0–4). Median number of trabectedin cycles received was 4 (range: 1–17). Best response assessed was stable disease ( n = 10, 50%), progressive disease ( n = 6, 30%), partial response ( n = 1, 5%), and not assessed in 3 patients. After a median follow-up of 19 months, median progression-free survival was 4 months.

Conclusion In this heavily treated population (composed of L-sarcomas and translocation-related sarcomas) with many patients with poor performance status, the outcome with trabectedin is in synchrony with literature. However, the need of 24-hour admission might deter quality of life. Elastomeric pump seems to be a reasonable alternative to admission and can be a breakthrough in administering trabectedin, especially in developing countries.

Molecular mechanisms underpinning sarcomas and implications for current and future therapy

Sarcomas are complex mesenchymal neoplasms with a poor prognosis. Their clinical management is highly challenging due to their heterogeneity and insensitivity to current treatments. Although there have been advances in understanding specific genomic alterations and genetic mutations driving sarcomagenesis, the underlying molecular mechanisms, which are likely to be unique for each sarcoma subtype, are not fully understood. This is in part due to a lack of consensus on the cells of origin, but there is now mounting evidence that they originate from mesenchymal stromal/stem cells (MSCs). To identify novel treatment strategies for sarcomas, research in recent years has adopted a mechanism-based search for molecular markers for targeted therapy which has included recapitulating sarcomagenesis using in vitro and in vivo MSC models. This review provides a comprehensive up to date overview of the molecular mechanisms that underpin sarcomagenesis, the contribution of MSCs to modelling sarcomagenesis in vivo, as well as novel topics such as the role of epithelial-to-mesenchymal-transition (EMT)/mesenchymal-to-epithelial-transition (MET) plasticity, exosomes, and microRNAs in sarcomagenesis. It also reviews current therapeutic options including ongoing pre-clinical and clinical studies for targeted sarcoma therapy and discusses new therapeutic avenues such as targeting recently identified molecular pathways and key transcription factors.

Comparison of first line chemotherapy regimens for advanced soft tissue sarcoma: a network meta-analysis

The best first line chemotherapy regimen for advanced soft tissue sarcoma (ASTS) remains inconclusive. Here, we aimed to find the best first line chemotherapy regimen by performing a network meta-analysis. Regimens were compared in terms of overall survival (OS), overall response rate(ORR), progression free survival (PFS), and toxicity. Twenty-eight eligible trials with a total of 6928 patients were included. EC (epirubicin + cisplatin) was considered as the better regimen for advanced STS with probability of 61.9% in terms of OS. However, this regimen only have been evaluated in a single small trial and tend to have more hematological toxicities than doxorubicin. No regimen was superior to doxorubicin with significant statistical difference in terms of PFS and ORR, even aldoxorubicin behaved better than doxorubicin in the network analysis. Collectively, doxorubicin still can be selected preferentially for the first line chemotherapy for patients.

Local control and postponement of systemic therapy after modest dose radiotherapy in oligometastatic myxoid liposarcomas

INTRODUCTION

Oligometastatic disease and/or oligoprogression in myxoid liposarcoma(oMLS) triggers discussions on local treatment options and delay of systemic treatments. We hypothesized that satisfactory local control and postponement of systemic therapy could be achieved with a modest radiotherapy(RT) dose in oMLS.

METHODS

The DOREMY trial is a multicenter, phase 2 trial evaluating efficacy and toxicity of a modest RT dose in both localized and oMLS; this report presents the data of the oMLS cohort treated with 36 Gy in 12-18 fractions with optional subsequent metastasectomy. The primary endpoint was local progression free survival(LPFS). Secondary endpoints included postponement of systemic therapy, symptom reduction, radiological objective response, and toxicity.

RESULTS

Nine patients with a total of 25 lesions were included, with a median follow-up of 23 months. The median number of lesions per patient was three and the trunk wall and bone were the most frequently affected sites. In lesions treated with definitive RT(n = 21), LPFS rates at 1, 2, and 3 years were respectively 73%, 61%, and 40%. Radiological objective response and clinical symptom reduction were achieved in 8/15(53%) and 9/10(90%) of the evaluable lesions, respectively. No local recurrences occurred in lesions treated with RT and metastasectomy(n = 4). For the entire study population, the median postponement of systemic therapy was 10 months. Grade ≥ 2 toxicity was observed in 2/9(22%) of patients.

CONCLUSIONS

This trial suggests that 36 Gy could possibly be effective to achieve local control, postpone systemic therapy and reduce symptoms in oMLS. Given the minimal toxicity this treatment could be reasonably considered in oMLS.

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.

Phase II study of concomitant radiotherapy with atezolizumab in oligometastatic soft tissue sarcomas: STEREOSARC trial protocol

INTRODUCTION

Up to 50% of soft tissue sarcoma (STS) patients develop metastases in the course of their disease. Cytotoxic therapy is a standard treatment in this setting but yields average tumour response rates of 25% at first line and ≤10% at later lines. In oligometastatic stage, stereotactic body radiation therapy (SBRT) allows reaching high control rates at treated sites (≥80%) and is potentially equally effective to surgery in term of overall survival. In order to shift the balance towards antitumour immunity by multisite irradiation, radiation could be combined with inhibitors of the immunosuppressive pathways.

METHODS AND ANALYSIS

STEREOSARC is a prospective, multicentric, randomised phase II, designed to evaluate the efficacy of SBRT associated with immunotherapy versus SBRT only. Randomisation is performed with a 2:1 ratio within two arms. The primary objective is to evaluate the efficacy, in term of progression-free survival (PFS) rate at 6 months, of immunomodulated stereotactic multisite irradiation in oligometastatic sarcoma patients. The secondary objectives include PFS by immune response criteria, overall survival, quality-of-life evaluation and developing mathematical models of tumour growth and dissemination predictive of oligometastatic versus polymetastatic evolution. Patients will be randomised in two groups: SBRT with atezolizumab and SBRT alone. The total number of included patients should be 103.

TRIAL REGISTRATION

The trial is registered on ClinicalTrials.gov (ID: NCT03548428).

ETHICS AND DISSEMINATION

This study has been approved by Comité de Protection des Personnes du sud-ouest et outre-mer 4 on 18 October 2019 (Reference CPP2019-09-076-PP) and from National Agency for Medical and Health products Safety (Reference: MEDAECNAT-2019-08-00004_2017-004239-35) on 18 September 2019.The results will be disseminated to patients upon individual request or through media release from scientific meetings. The results will be communicated through scientific meetings and publications.

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.

Activity of PD1 inhibitor therapy in advanced sarcoma: a single-center retrospective analysis

BACKGROUND

Sarcomas constitute a heterogeneous group of tumors with different clinical behaviors and variable responses to systemic therapies. Recent immunotherapy studies with PD1 inhibitors (PD1i) show promising results with use in certain soft-tissue sarcomas; however, the clinical and molecular features that best predict response to PD1i remain unclear.

METHODS

Demographic, imaging, histologic, and genetic sequencing data was collected for sarcoma patients who received nivolumab or pembrolizumab (PD1i) treatment at our institution between January 1st 2015 and April 23rd 2018. The primary objective was to determine progression-free survival (PFS) in patients with advanced sarcomas receiving PD1i. Secondary objectives included determining overall survival (OS) and assessment of characteristics associated with response to PD1i. Fifty-six patients who were treated with PD1i therapy met inclusion criteria for this study.

RESULTS

Partial response towards PD1i treatment was seen in 3 in 26 evaluable patients, but no complete responses were observed (overall response rate 11.5%). Within this group of patients, the 90 day PFS was found to be 48.8%. In patients in whom PD1 expression was known, there was a statistically significant positive correlation between expression of PD1 and longer PFS and OS rates. Patients that were treated with more than four cycles of PD1i therapy were also more likely to have a greater OS.

CONCLUSIONS

This study suggests activity of PD1i in a pretreated cohort of advanced sarcoma patients, particularly for the subset of patients with PD1 positive tumors. Our results highlight the importance of further research to better target the optimal patient population and markers of response.

Update on systemic therapy for advanced soft-tissue sarcoma

Background

Soft-tissue sarcoma (sts) represents a rare group of mesenchymal neoplasms comprising more than 50 heterogeneous subtypes. Great efforts have been made to increase the understanding of the treatment of advanced sts (unresectable or metastatic disease). We set out to determine whether outcomes for patients with advanced sts have improved over time and to assess the current evidence for systemic therapy.

Methods

In a scoping review, we evaluated the contemporary evidence for systemic treatment of advanced sts in adults (>18 years of age). Phase i, ii, and iii studies of systemic therapy for advanced sts published in the English language were included. After abstract and full-text review of seventy-seven studies, sixty-two trials met the inclusion criteria.

Results

The number of clinical trials conducted and published in advanced sts has increased over the last 30 years. Although median overall survival has increased, attempts at improving first-line therapy through dose intensification, doublet chemotherapy, or alternative backbones have not been successful. The optimal therapy beyond anthracyclines remains a challenge, especially given the heterogeneity that grouping multiple sts subtypes within clinical trials creates. However, increasing numbers of agents are being studied, and several studies had shown isolated benefit in progression-free or overall survival.

Summary

First-line systemic therapy with an anthracycline remains the standard of care for advanced sts. However, choice of subsequent therapy beyond anthracyclines remains challenging. Novel systemic therapies, use of molecular diagnostics to direct therapy, subtype-specific trials, and learnings from real-world retrospective data are all important for improving outcomes in patients with advanced sts.

Precision Medicine in Soft Tissue Sarcoma Treatment

Soft tissue sarcoma (STS) is a rare component of malignant diseases. STS includes various histological subtypes, and there are some important differences among the different histological subtypes regarding the mutation profile and sensitivity to antitumor agents. Many clinical trials of STS incorporating many different histological subtypes in various populations have been conducted; it is difficult to compare the findings and make conclusions about clinical efficacy. Targeted therapies focusing on specific histological subtypes and precision therapy focusing on the specific genetic mutation(s) of each STS patient are being investigated. Since STS patients are a small population, new clinical trial designs are required to evaluate and establish new targeted therapies for each histological subtype that has a limited number of patients, and preclinical investigations are needed to detect targetable mutations. Now that cancer genome profiling is used in clinical practice, it is urgently necessary to connect the genome profiling data obtained in clinical settings to the optimal clinical treatment strategies. Herein we review the development and challenges of precision therapy in the management of STS patients.

Long-term disease control by trabectedin in a patient with dedifferentiated liposarcoma: A case report

RATIONALE

Trabectedin is an antitumor drug considered to be effective for liposarcoma, leiomyosarcoma, and translocation-related sarcoma. Concerning liposarcoma subtypes, evidence of the efficacy of trabectedin for dedifferentiated liposarcoma (DDLPS) is poor, whereas it is known to have high efficacy against myxoid liposarcoma. Moreover, there are few reports of long-term trabectedin treatment of cases of DDLPS. Here, we present a case of advanced metastatic DDLPS that achieved long-term disease control by trabectedin treatment.

PATIENT CONCERNS

A 68-year-old man presented with a mass in his back. Magnetic resonance imaging showed a tumorous mass in his back which exhibited low intensity on T1-weighted and high intensity on T2-weighted images.

DIAGNOSIS

The mass was diagnosed as DDLPS by open biopsy.

INTERVENTIONS

The patient underwent gemcitabine+docetaxel combination therapy followed by pazopanib and eribulin; all these therapies failed to halt disease progression. Subsequently, we changed the regimen to trabectedin as fourth-line therapy.

OUTCOME

The patient achieved stable disease for approximately 18 months during 11 cycles of trabectedin therapy.

LESSONS

Trabectedin should be considered as a treatment option for DDLPS even in cases of numerous failed prior chemotherapy regimens.

Pharmacotherapy for liposarcoma: current state of the art and emerging systemic treatments

Introduction: Liposarcomas are a heterogeneous group of soft tissue tumors that arise from adipose tissue and are one of the most common soft tissue sarcomas found in adults. Liposarcomas are subclassified into four subtypes with distinct histologic and biologic features that influence their treatment and management. Areas covered: This manuscript reviews the key clinicopathologic and cytogenic characteristics of the liposarcoma histologic subtypes and summarizes the results of recent clinical trials, treatment options, and future directions in the pharmacotherapy for the management of liposarcoma. Expert opinion: Despite significant advancements in the management of this disease, the treatment of liposarcoma continues to be a challenge. Surgical resection remains the mainstay of treatment for localized disease; however, use of systemic therapies in conjunction with surgery may be considered in patients where tumor shrinkage could reduce surgical morbidity and in patients with high-risk of micrometastatic disease. Anthracycline-based chemotherapy regimens remain the standard first-line treatment for unresectable/metastatic liposarcoma. Trabectedin and eribulin are currently the two most promising and evidenced-based second-line treatment options for liposarcomas. However, multiple clinical trials dedicated to patients with liposarcoma evaluating novel targeted agents are ongoing. Every effort should be made to enroll patients with liposarcoma into histotype-specific clinical trials.

Using biology to guide the treatment of sarcomas and aggressive connective-tissue tumours

Sarcomas are a heterogeneous group of malignancies that arise from cells of a mesenchymal origin. Surgery forms the mainstay of the treatment of most patients with localized sarcoma and might be followed or preceded by chemotherapy and/or radiotherapy. In the metastatic setting, systemic treatments tend to improve survival and control symptoms. However, the adverse events and sometimes disappointing outcomes associated with these empirical approaches to treatment indicate a need for new approaches. The advent of next-generation sequencing (NGS) has enabled more targeted treatment of many malignancies based on the presence of specific alterations. NGS analyses of sarcomas have revealed the presence of many alterations that can be targeted using therapies that are already used in patients with other forms of cancer. In this Review, we describe the genomic alterations considered to define specific nosological subgroups of sarcoma and whose contribution to oncogenesis provides a biological rationale for the use of a specific targeted therapy. We also report several less successful examples that should guide researchers and clinicians to better define the extent to which the identification of driver molecular alterations should influence the development of novel treatments.

Surrogacy of intermediate endpoints for overall survival in randomized controlled trials of first-line treatment for advanced soft tissue sarcoma in the pre- and post-pazopanib era: a meta-analytic evaluation

Background

Overall survival is the true endpoint for most randomized controlled trials (RCTs) of malignant tumors, whereas progression-free survival (PFS) is considered the most reliable surrogate endpoint for overall survival (OS). The present study aimed to evaluate the correlation between surrogate endpoints and OS in randomized trials of first-line chemotherapy with doxorubicin (DOX), the standard treatment for advanced and metastatic soft tissue sarcomas (ASTS), using a meta-analytic approach.

Methods

In a systematic review, we identified RCTs of first-line chemotherapy for ASTS that compared single-agent doxorubicin (DOX) with other chemotherapy regimens, and were published in English during January 1974–December 2017. A meta-analysis was performed to evaluate the efficacy of first-line treatments for ASTS. Surrogacy of the intermediate endpoints for OS was investigated using weighted linear regression analysis. Correlation strength was examined using the coefficient of determination (R²).

Results

Twenty-seven randomized trials, comprising 6156 patients (3371 patients in the experimental arm and 2785 patients in the DOX arm) were identified. The hazard ratios for OS and PFS showed that the efficacy of treatment for ASTS was not significantly different between standard DOX and experimental treatments. The median OS was significantly prolonged in RCTs published after 2012 when pazopanib was approved for treating ASTS. The median PFS, however, did not differ significantly. The correlation between PFS and OS was moderate (R² = 0.557), but better than that between OS and 3-month PFS, 6-month PFS, and response rate (R² = 0.200, 0.073, and 0.278, respectively). The correlation between PFS and OS tended to be more favorable in RCTs published after 2012 (R² = 0.586 and 0.459, respectively).

Conclusions

The trial-level correlation between PFS and OS was only modest; it tended to be better in RCTs published after 2012. While the effective lines of chemotherapy and the introduction of new drugs prolonged OS but not PFS, PFS is a better surrogate than other intermediate endpoints in the first-line ASTS trials even in the post-pazopanib era. Although this does not negate the need for more reliable surrogate endpoints for OS.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5268-2) contains supplementary material, which is available to authorized users.

A meta-analysis of randomized controlled trials that compare standard doxorubicin with other first-line chemotherapies for advanced/metastatic soft tissue sarcomas

Objective

The standard treatment for patients with advanced/metastatic soft tissue sarcomas (ASTS) is systemic chemotherapy with doxorubicin. A previous meta-analysis of 8 randomized controlled trials (RCTs) demonstrated the superiority of single-agent doxorubicin over doxorubicin-based combination chemotherapy for ASTS. However, meta-analyses of all RCTs that compare doxorubicin to other single-agent or combination regimens as first-line treatments for ASTS are lacking. We conducted a systematic review and meta-analysis to evaluate the efficacy and toxicity of current primary treatments for ASTS.

Methods

Eligible studies were RCTs of first-line chemotherapies for ASTS comparing doxorubicin alone to other single agents or to combination therapies (experimental arm). Data from studies reporting hazard ratios (HR) and 95% confidence intervals (CI) for overall survival (OS) and progression-free survival (PFS) were pooled. Other time-to-event endpoints were extracted from the studies based on Kaplan-Meier estimates, and pooled odds ratios (OR) and 95% CI were calculated.

Results

Twenty-seven eligible RCTs comprising 6156 patients were identified. Overall, the 1-year OS (OR 0.88, 95% CI 0.79–0.99, P = 0.03) was significantly improved in the experimental arm over the doxorubicin-only arm; however, there was no significant difference in 2-year OS (OR 0.87, 95% CI 0.73–1.03, P = 0.11) or OS (HR 0.97, 95% CI 0.91–1.03, P = 0.28) between the two groups. PFS and other time-to-event endpoints were not significantly different between the two treatment arms. While incidences of overall severe adverse events were not significantly different (OR 1.20, 95% CI 0.88–1.65, P = 0.26), severe nausea/vomiting was significantly more frequent in the experimental arm (OR 1.90, 95% CI 1.27–2.83, P = 0.002).

Conclusion

The efficacies of doxorubicin-only and experimental arm regimens were similar, although toxicities were more frequent in the experimental arms. Hence, doxorubicin monotherapy remains suitable as a standard first-line regimen for ASTS.

Safety and tolerability of lurbinectedin (PM01183) in patients with acute myeloid leukemia and myelodysplastic syndrome

Trabectedin is an FDA-approved DNA minor groove binder that has activity against translocation-associated sarcomas. Lurbinectedin is a next-generation minor groove binder with preclinical activity against myeloid leukemia cells. A dose-finding phase 1 clinical trial was performed in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) with further assessment of safety and tolerability. Forty-two patients with relapsed/refractory AML/MDS received lurbinectedin administered as a 1-hour intravenous infusion in a 3 + 3 study design. Two dosing schedules were used: 3.5, 5, 7, or 6 mg on days 1 and 8 or 2, 3, 1, or 1.5 mg for 3 consecutive days on days 1 to 3. Three patients experienced dose-limiting toxicities of rhabdomyolysis (grade 4), hyperbilirubinemia (grade 3), and oral herpes (grade 3) with the day 1 and 8 schedule. Otherwise, adverse events mainly consisted of gastrointestinal manifestations (n = 11), febrile neutropenia/infections (n = 4), pulmonary toxicity (n = 2), and renal failure (n = 2). The most common laboratory abnormalities observed were an increase in creatinine (93%) and anemia, neutropenia, and thrombocytopenia (100%). Overall, 33 of 42 patients (79%) had reduction in blasts in peripheral blood or bone marrow. One patient achieved a partial response and 2 patients a morphologic leukemia-free state. Most (n = 30, 71%) were discontinued due to progressive disease. Early deaths occurred from disease-related causes that were not attributable to lurbinectedin. Four patients with a chromosome 11q21-23 abnormality had significantly greater bone marrow blast reduction than those without such abnormality, with decrease of 31 ± 14% (n = 4) vs 8 ± 8% (n = 16), respectively (P = .04). Overall, lurbinectedin was safe and tolerated using the schedules and dose levels tested. While no sustained remissions were observed, single-agent lurbinectedin was transiently leukemia suppressive for some patients.

Translocation-Related Sarcomas

Chromosomal translocations are observed in approximately 20% of soft tissue sarcomas (STS). With the advances in pathological examination technology, the identification of translocations has enabled precise diagnoses and classifications of STS, and it has been suggested that the presence of and differences in translocations could be prognostic factors in some translocation-related sarcomas. Most of the translocations in STS were not regarded as targets of molecular therapies until recently. However, trabectedin, an alkylating agent, has shown clinical benefits against translocation-related sarcoma based on a modulation of the transcription of the tumor's oncogenic fusion proteins. Many molecular-targeted drugs that are specific to translocations (e.g., anaplastic lymphoma kinase and tropomyosin kinase related fusion proteins) have emerged. The progress in gene technologies has allowed researchers to identify and even induce new translocations and fusion proteins, which might become targets of molecular-targeted therapies. In this review, we discuss the clinical significance of translocation-related sarcomas, including their diagnoses and targeted therapies.

Adaptive designs in clinical trials: from scientific advice to marketing authorisation to the European Medicine Agency

Background

In recent years, experience on the application of adaptive designs in confirmatory clinical trials has accumulated. Although planning such trials comes at the cost of additional operational complexity, adaptive designs offer the benefit of flexibility to update trial design and objectives as data accrue. In 2007, the European Medicines Agency (EMA) provided guidance on confirmatory clinical trials with adaptive (or flexible) designs. In order to better understand how adaptive trials are implemented in practice and how they may impact medicine approval within the EMA centralised procedure, we followed on 59 medicines for which an adaptive clinical trial had been submitted to the EMA Scientific Advice (SA) and analysed previously in a dedicated EMA survey of scientific advice letters. We scrutinized in particular the submission of the corresponding medicines for a marketing authorisation application (MAA). We also discuss the current regulatory perspective as regards the implementation of adaptive designs in confirmatory clinical trials.

Methods

Using the internal EMA MAA database, the AdisInsight database and related trial registries, we analysed how many of these 59 trials actually started, the completion status, results, the time to trial start, the adaptive elements finally implemented after SA, their possible influence on the success of the trial and corresponding product approval.

Results

Overall 31 trials out of 59 (53%) were retrieved. Thirty of them (97%) have been started and 23 (74%) concluded. Nine of these trials (39% out of 23) demonstrated a significant treatment effect on their primary endpoint and 4 (17% out of 23) supported a marketing authorisation (MA). An additional two trials were stopped using pre-defined criteria for futility, efficiently identifying trials on which further resources should not be spent. Median time to trial start after SA letter was given by EMA was 5 months. In the investigated trial registries, at least 18 trial (58% of 31 retrieved trials) designs were implemented with adaptive elements, which were predominantly dose selection, sample size reassessment (SSR) and stopping for futility (SFF). Among the 11 completed trials including adaptive elements, 6 demonstrated a significant treatment effect on their primary endpoint (55%).

Conclusions

Adaptive designs are now well established in the drug development landscape. If properly pre-planned, adaptations can play a key role in the success of some of these trials, for example to help successfully select the most promising dose regimens for phase II/III trials. Interim analyses can also enable stopping of trials for futility when they do not hold their promises. Type I error rate control, trial integrity and results consistency between the different stages of the analyses are fundamental aspects to be discussed thoroughly. Engaging early dialogue with regulators and implementing the scientific advice received is strongly recommended, since much experience in discussing adaptive designs and assessing their results has been accumulated.

Nation-wide survey of advanced non-melanoma skin cancers treated at dermatology departments in Japan

BACKGROUND

There are limited treatment options for advanced non-melanoma skin cancers (NMSCs). To overcome this issue, we need to conduct clinical studies, however, there is a lack of information on how many patients with advanced NMSCs are treated annually in Japan.

OBJECTIVE

To investigate the actual number of advanced NMSC patients in Japan.

METHODS

A questionnaire survey was sent to 668 institutes to educe information on: 1) the numbers of patients with squamous cell carcinoma (SCC), extramammary Paget disease (EMPD), other skin origin carcinomas, and cutaneous angiosarcoma (CAS) admitted in 2016 and 2017; 2) the preferred first- and second-line chemotherapies; and 3) the anticipated for future development.

RESULTS

Questionnaires were returned from 383 (57.3%) institutes. They reported a total of 1765 patients over the 2 years. The annual number patients with SCC, EMPD, other skin carcinomas, and CAS was 323.5, 192.5, 126, and 240.5, respectively. We estimated the annual number of patients for all 668 institutes to be 1255.6. Current first- and second-line treatment for NMSCs were chemotherapy regimens, but immune checkpoint inhibitors were the most anticipated new drugs for SCC and CAS, while chemotherapy was still the most anticipated treatment for EMPD.

CONCLUSION

Considering that during 2017, the number of deaths in Japan due to NMSC was reported to be 948, our estimated annual number of patients with NMSCs, 1255.6 seems to be an accurate estimation. As most of the treatment options for advanced NMSCs are outdated, the results of this study should be used to propose clinical studies.

Systematic bias between blinded independent central review and local assessment: literature review and analyses of 76 phase III randomised controlled trials in 45 688 patients with advanced solid tumour

OBJECTIVE

Unbiased assessment of tumour response is crucial in randomised controlled trials (RCTs). Blinded independent central review is usually used as a supplemental or monitor to local assessment but is costly. The aim of this study is to investigate whether systematic bias existed in RCTs by comparing the treatment effects of efficacy endpoints between central and local assessments.

DESIGN

Literature review, pooling analysis and correlation analysis.

DATA SOURCES

PubMed, from 1 January 2010 to 30 June 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligible articles are phase III RCTs comparing anticancer agents for advanced solid tumours. Additionally, the articles should report objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) or time to progression (TTP); the treatment effect of these endpoints, OR or HR, should be based on central and local assessments.

RESULTS

Of 76 included trials involving 45 688 patients, 17 (22%) trials reported their endpoints with statistically inconsistent inferences (p value lower/higher than the probability of type I error) between central and local assessments; among them, 9 (53%) trials had statistically significant inference based on central assessment. Pooling analysis presented no systematic bias when comparing treatment effects of both assessments (ORR: OR=1.02 (95% CI 0.97 to 1.07), p=0.42, I2=0%; DCR: OR=0.97 (95% CI 0.92 to 1.03), p=0.32, I2=0%); PFS: HR=1.01 (95% CI 0.99 to 1.02), p=0.32, I2=0%; TTP: HR=1.04 (95% CI 0.95 to 1.14), p=0.37, I2=0%), regardless of funding source, mask, region, tumour type, study design, number of enrolled patients, response assessment criteria, primary endpoint and trials with statistically consistent/inconsistent inferences. Correlation analysis also presented no sign of systematic bias between central and local assessments (ORR, DCR, PFS: r>0.90, p<0.01; TTP: r=0.90, p=0.29).

CONCLUSIONS

No systematic bias could be found between local and central assessments in phase III RCTs on solid tumours. However, statistically inconsistent inferences could be made in many trials between both assessments.

Survival of adults with cancers of bone or soft tissue in Europe-Report from the EUROCARE-5 study

BACKGROUND

Five-year relative survival (RS) of adults with bone and soft-tissue cancers in Europe was still <60% by 1995-1999. There was large geographical survival variability, mainly for bone tumours, and survival decreased with increasing age at diagnosis.

METHODS

Data from 87 population-based cancer registries in 29 countries, extracted from the EUROCARE-5 database, were used to provide updated estimates of survival and describe trends in survival of adults with cancers of these sites across Europe. We calculated 5-year RS for patients diagnosed in 2000-2007. We estimated 5-year RS by the period approach to assess changes in survival between 1999-2001, 2002-2004 and 2005-2007, and provide reliable predictions for recently diagnosed patients.

RESULTS

Five-year RS was 60% for adults diagnosed with soft-tissue cancer in 2000-2007 and 53% for those with bone cancer. RS declined with increasing age at diagnosis, especially for bone cancer. Survival from bone cancer varied widely between European regions, from 63 to 62% in Northern and Central Europe to 39% in Eastern Europe. Inter-regional variation was much less for soft-tissue cancer. For both site groupings, there was little evidence of change in five-year RS up to 2002-2004, followed by increases of 3-4% during 2005-2007.

CONCLUSIONS

Outcomes for adults with bone and soft-tissue cancer in Europe began to improve around 2005; new therapeutic developments are expected to result in further progress. Survival improvements already achieved must be brought more fully to elderly patients and those in Eastern Europe. European Reference Networks on rare cancers will have a vital role in future progress.

Starvation tactics using natural compounds for advanced cancers: pharmacodynamics, clinical efficacy, and predictive biomarkers

The high mortality associated with oncological diseases is mostly due to tumors in advanced stages, and their management is a major challenge in modern oncology. Angiogenesis is a defined hallmark of cancer and predisposes to metastatic invasion and dissemination and is therefore an important druggable target for cancer drug discovery. Recently, because of drug resistance and poor prognosis, new anticancer drugs from natural sources targeting tumor vessels have attracted more attention and have been used in several randomized and controlled clinical trials as therapeutic options. Here, we outline and discuss potential natural compounds as salvage treatment for advanced cancers from recent and ongoing clinical trials and real-world studies. We also discuss predictive biomarkers for patients' selection to optimize the use of these potential anticancer drugs.

Primary breast angiosarcoma - a single institution experience from a tertiary cancer center in South India

INTRODUCTION

Primary angiosarcoma of the breast is a rare entity with incidence of less than 0.05% of all malignant breast neoplasms. It occurs in young females without any associated risk factors. The tumor behaves aggressively and has a poor prognosis compared to invasive ductal carcinoma.

METHOD

It was a retrospective observational study done at a tertiary cancer center from January 2012 to December 2016. The medical records of patients diagnosed with primary breast angiosarcoma were reviewed for the study. Clinicopathological profile, treatment, and the outcomes were analyzed.

RESULTS

Four patients were diagnosed with primary breast angiosarcoma out of 2560 breast cancer patients seen over a period of 5 years. Two had metastatic disease at presentation. Among four patients, two underwent surgery of the primary tumor, whereas, all received chemotherapy either as adjuvant or palliative setting. One patient received adjuvant radiation therapy. Three patients received 2nd line and one received 3rd line chemotherapy on disease progression. After a median follow-up of 18 months one patient was surviving on 3rd line chemotherapy with trabectedin. Other three succumbed to disease after progression.

CONCLUSION

Due to a small number of this malignancy randomized studies are difficult to perform and optimum treatment strategy still need to be defined.

Clinical and Molecular Spectrum of Liposarcoma

Liposarcomas are rare malignant tumors of adipocytic differentiation. The classification of liposarcomas into four principal subtypes reflects the distinct clinical behavior, treatment sensitivity, and underlying biology encompassed by these diseases. Increasingly, clinical management decisions and the development of investigational therapeutics are informed by an improved understanding of subtype-specific molecular pathology. Well-differentiated liposarcoma is the most common subtype and is associated with indolent behavior, local recurrence, and insensitivity to radiotherapy and chemotherapy. Dedifferentiated liposarcoma represents focal progression of well-differentiated disease into a more aggressive, metastasizing, and fatal malignancy. Both of these subtypes are characterized by recurrent amplifications within chromosome 12, resulting in the overexpression of disease-driving genes that have been the focus of therapeutic targeting. Myxoid liposarcoma is characterized by a pathognomonic chromosomal translocation that results in an oncogenic fusion protein, whereas pleomorphic liposarcoma is a karyotypically complex and especially poor-prognosis subtype that accounts for less than 10% of liposarcoma diagnoses. A range of novel pharmaceutical agents that aim to target liposarcoma-specific biology are under active investigation and offer hope of adding to the limited available treatment options for recurrent or inoperable disease.

Systemic Therapy in Metastatic or Unresectable Well-Differentiated/Dedifferentiated Liposarcoma

Liposarcoma is one of the most common subtypes of soft-tissue sarcoma and consists of three main subtypes, of which well-differentiated liposarcoma and dedifferentiated liposarcoma account for 40–45%. The current mainstay of systemic treatment for patients with metastatic or unresectable disease remains doxorubicin with or without ifosfamide in the first-line setting. Recently, eribulin and trabectedin have been approved by the US Food and Drug Administration for recurrent liposarcomas and progress in molecular characterization of these tumors has opened up new and potential novel treatment targets. This review will focus on the evidence base for current treatment strategies and will also discuss potential future options.

Trabectedin and Eribulin: Where Do They Fit in the Management of Soft Tissue Sarcoma?

OPINION STATEMENT

Trabectedin and eribulin are two agents that have been recently approved for the treatment of specific soft tissue sarcoma subtypes. They have proved to be a much-needed line of additional treatment for patients with these rare tumors, but their activity remains admittedly modest in most cases. Further exploitation of these novel agents is likely to require a more granular understanding of the salient mechanisms of action. For example, if as some studies suggest, eribulin derives its benefit from restructuring of tumor vasculature to improve efficacy of subsequent lines of therapy, then patients may benefit from its use earlier in the treatment pathway. The sequencing of trabectedin with other agents is also worth examining. In a disease like myxoid liposarcoma, consideration should be given to using trabectedin before other salvage regimens like gemcitabine and docetaxel, given its tolerability and excellent efficacy against this sarcoma subtype. Also, to be further investigated is the use of trabectedin in sarcoma subtypes which were excluded from the phase III study, but in which activity has been documented in earlier trials and subsequent reports. Combinations of trabectedin with other agents, particularly doxorubicin, have been explored, but the data to date do not support the routine use of these regimens.

Injectable and Self-Healing Thermosensitive Magnetic Hydrogel for Asynchronous Control Release of Doxorubicin and Docetaxel to Treat Triple-Negative Breast Cancer

Integration of two or more drugs into a multiagent delivery system has been considered to have profound impact on both in vitro and in vivo cancer treatment due to their efficient synergistic effect. This study presents a cheap and simple chitosan hydrogel cross-linked with telechelic difunctional poly(ethylene glycol) (DF-PEG-DF) for synthesis of an injectable and self-healing thermosensitive dual-drug-loaded magnetic hydrogel (DDMH), which contains both doxorubicin (DOX) and docetaxel (DTX) for chemotherapy and iron oxide for magnetic hyperthermia induced stimuli responsive drug release. The as-prepared DDMH not only have good biocompatibility but also exhibit unique self-healing, injectable, asynchronous control release properties. Meanwhile, it shows an excellent magnetic field responsive heat-inducing property, which means that DDMH will produce a large amount of heat to control the surrounding temperature under the alternative magnetic field (AMF). A remarkably improved synergistic effect to triple negative breast cancer cell line is obtained by comparing the therapeutic effect of codelivery of DOX and DTX/PLGA nanoparticles (DTX/PLGA NPs) with DOX or DTX/PLGA NPs alone. In vivo results showed that DDMH exhibited significant higher antitumor efficacy of reducing tumor size compared to single drug-loaded hydrogel. Meanwhile, the AMF-trigger control release of drugs in codelivery system has a more efficient antitumor effect of cancer chemotherapy, indicating that DDMH was a promising multiagent codelivery system for synergistic chemotherapy in the cancer treatment field.

Trabectedin is a promising antitumor agent potentially inducing melanocytic differentiation for clear cell sarcoma

Clear cell sarcoma is an aggressive soft tissue sarcoma and highly resistant to conventional chemotherapy and radiation therapy. This devastating disease is defined by EWSR1-ATF1 fusion gene resulting from chromosomal translocation t(12;22)(q13;q12) and characterized by melanocytic differentiation. A marine-derived antineoplastic agent, trabectedin, inhibits the growth of myxoid liposarcoma and Ewing sarcoma by causing adipogenic differentiation and neural differentiation, respectively. In this study, we examined the antitumor effects and mechanism of action of trabectedin on human clear cell sarcoma cell lines. We showed that trabectedin decreased the cell proliferation of five clear cell sarcoma cell lines in a dose-dependent manner in vitro and reduced tumor growth of two mouse xenograft models. Flow cytometry and immunoblot analyses in vitro and immunohistochemical analysis in vivo revealed that trabectedin-induced G2/M cell cycle arrest and apoptosis. Furthermore, trabectedin increased the expression of melanocytic differentiation markers along with downregulation of ERK activity in vitro and the rate of melanin-positive cells in vivo. These results suggest that trabectedin has potent antitumor activity against clear cell sarcoma cells by inducing cell cycle arrest, apoptosis, and, in part, by promoting melanocytic differentiation through inactivation of ERK signaling. Our present study indicates that trabectedin is a promising differentiation-inducing agent for clear cell sarcoma.

Treatment of advanced, metastatic soft tissue sarcoma: latest evidence and clinical considerations

Soft tissue sarcoma (STS) is a biologically heterogeneous malignancy with over 50 subtypes. Historically, there have been few systemic treatment options for this relatively rare disease. Traditional cytotoxic agents, such as anthracyclines, alkylating agents, and taxanes have limited clinical benefit beyond the first-line setting; across all high-grade STS subtypes, median overall survival remains approximately 12-18 months for advanced metastatic disease. The development of targeted therapies has led to recent US Food and Drug Administration approval of four new treatments for high-grade STS in the advanced metastatic setting. Among these, olaratumab is most notable for its improvement in overall survival for patients with anthracycline-naïve disease. Further progress in STS management will rely on novel trial design, subtype-specific therapies and validation of biomarkers to tailor therapy. Immunotherapy has shown promise as a new, but yet undiscovered frontier in the management of STS.

Olaratumab: PDGFR-α inhibition as a novel tool in the treatment of advanced soft tissue sarcomas

Advanced soft tissue sarcomas are aggressive cancers with limited therapeutic options. Recently, inhibition of platelet-derived growth factor receptor (PDGFR)-α by the monoclonal antibody olaratumab showed promising clinical activity. If confirmed, this would be one of the first examples of targeted therapy effective in advanced soft tissue sarcomas therapy independently of the histologic subtype. Here, we reviewed the biology of the PDGF/PDGFR axis, particularly focusing on its role in cancer, and then we discussed on the effects of PDGFR-α inhibition in the therapy of advanced soft tissue sarcomas.

Systemic Treatments in Soft Tissue Sarcomas

Systematic treatment of adult-type soft tissue sarcoma is evolving. Its role in the neoadjuvant setting is currently experimental, whereas the data on adjuvant chemotherapy are inconclusive. Nevertheless, in clinical practice, neoadjuvant and adjuvant chemotherapy may be considered on an individual basis after multidisciplinary discussion. Systemic therapy has a well-established role in the management of locally advanced and metastatic disease and histology-based treatment approaches are being studied.

Trabectedin and Campthotecin Synergistically Eliminate Cancer Stem Cells in Cell-of-Origin Sarcoma Models

Trabectedin has been approved for second-line treatment of soft tissue sarcomas. However, its efficacy to target sarcoma initiating cells has not been addressed yet. Here, we used pioneer models of myxoid/round cell liposarcoma (MRCLS) and undifferentiated pleomorphic sarcoma (UPS) developed from transformed human mesenchymal stromal/stem cells (MSCs) to evaluate the effect of trabectedin in the cell type responsible for initiating sarcomagenesis and their derived cancer stem cells (CSC) subpopulations. We found that low nanomolar concentrations of trabectedin efficiently inhibited the growth of sarcoma-initiating cells, induced cell cycle arrest, DNA damage and apoptosis. Interestingly, trabectedin treatment repressed the expression of multiple genes responsible for the development of the CSC phenotype, including pluripotency factors, CSC markers and related signaling pathways. Accordingly, trabectedin induced apoptosis and reduced the survival of CSC-enriched tumorsphere cultures with the same efficiency that inhibits the growth of bulk tumor population. In vivo, trabectedin significantly reduced the mitotic index of MRCLS xenografts and inhibited tumor growth at a similar extent to that observed in doxorubicin-treated tumors. Combination of trabectedin with campthotecin (CPT), a chemotherapeutic drug that shows a robust anti-tumor activity when combined with alkylating agents, resulted in a very strong synergistic inhibition of tumor cell growth and highly increased DNA damage and apoptosis induction. Importantly, the enhanced anti-tumor activity of this combination was also observed in CSC subpopulations. These data suggest that trabectedin and CPT combination may constitute a novel strategy to effectively target both the cell-of-origin and CSC subpopulations in sarcoma.

PARP1 expression drives the synergistic antitumor activity of trabectedin and PARP1 inhibitors in sarcoma preclinical models

Background

Enhancing the antitumor activity of the DNA-damaging drugs is an attractive strategy to improve current treatment options. Trabectedin is an isoquinoline alkylating agent with a peculiar mechanism of action. It binds to minor groove of DNA inducing single- and double-strand-breaks. These kinds of damage lead to the activation of PARP1, a first-line enzyme in DNA-damage response pathways. We hypothesized that PARP1 targeting could perpetuate trabectedin-induced DNA damage in tumor cells leading finally to cell death.

Methods

We investigated trabectedin and PARP1 inhibitor synergism in several tumor histotypes both in vitro and in vivo (subcutaneous and orthotopic tumor xenografts in mice). We searched for key determinants of drug synergism by comparative genomic hybridization (aCGH) and gene expression profiling (GEP) and validated their functional role.

Results

Trabectedin activated PARP1 enzyme and the combination with PARP1 inhibitors potentiated DNA damage, cell cycle arrest at G2/M checkpoint and apoptosis, if compared to single agents. Olaparib was the most active PARP1 inhibitor to combine with trabectedin and we confirmed the antitumor and antimetastatic activity of trabectedin/olaparib combination in mice models. However, we observed different degree of trabectedin/olaparib synergism among different cell lines. Namely, in DMR leiomyosarcoma models the combination was significantly more active than single agents, while in SJSA-1 osteosarcoma models no further advantage was obtained if compared to trabectedin alone. aCGH and GEP revealed that key components of DNA-repair pathways were involved in trabectedin/olaparib synergism. In particular, PARP1 expression dictated the degree of the synergism. Indeed, trabectedin/olaparib synergism was increased after PARP1 overexpression and reduced after PARP1 silencing.

Conclusions

PARP1 inhibition potentiated trabectedin activity in a PARP1-dependent manner and PARP1 expression in tumor cells might be a useful predictive biomarker that deserves clinical evaluation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0652-5) contains supplementary material, which is available to authorized users.