Treatment of patients with advanced soft tissue sarcoma: disappointment or challenge?

Primary leiomyosarcoma of the middle ureter: A rare case report with literature review

Leiomyosarcoma is a rarely seen neoplasm of the ureter. Malignant tumors of smooth muscle of the ureter are extremely rare, and about 22 cases of leiomyosarcoma of ureter have been reported to date. A 57-year-old diabetic Pakistani man presented with a dull ache pain in the right flank. Past surgical history was three ureteroscopic surgeries for a ureteric stricture. Computed tomography showed a stricture with a peri-ureteral soft tissue mass of 11 mm x 5 mm at the middle third of the ureter at the level of common iliac vessels. laparoscopic excision with safety margin and right ureterovesical reimplantation is performed. Diagnosis of leiomyosarcoma of the right ureter was made, and one iliac lymph node was excised and was positive for tumor by pathologic examination. Although leiomyosarcoma is rarely seen in urinary tract, it should be considered in the differential diagnosis of ureteral stricture disease and retroperitoneal tumors.

Magnetic Resonance Imaging-Based Radiomics Nomogram for Prediction of the Histopathological Grade of Soft Tissue Sarcomas: A Two-Center Study

BACKGROUND

Preoperative prediction of soft tissue sarcoma (STS) grade is important for treatment decisions. Therefore, formulation an STS grade model is strongly needed.

PURPOSE

To develop and test an magnetic resonance imaging (MRI)-based radiomics nomogram for predicting the grade of STS (low-grade vs. high grade).

STUDY TYPE

Retrospective POPULATION: One hundred and eighty patients with STS confirmed by pathologic results at two independent institutions were enrolled (training set, N = 109; external validation set, N = 71).

FIELD STRENGTH/SEQUENCE

Unenhanced T1-weighted (T1WI) and fat-suppressed T2-weighted images (FS-T2WI) were acquired at 1.5 T and 3.0 T.

ASSESSMENT

Clinical-MRI characteristics included age, gender, tumor-node-metastasis (TNM) stage, American Joint Committee on Cancer (AJCC) stage, progression-free survival (PFS), and MRI morphological features (ie, margin). Radiomics feature extraction were performed on T1WI and FS-T2WI images by minimum redundancy maximum relevance (MRMR) method and least absolute shrinkage and selection operator (LASSO) algorithm. The selected features constructed three radiomics signatures models (RS-T1， RS-FST2, and RS-Combined). Univariate and multivariate logistic regression analysis were applied for screening significant risk factors. Radiomics nomogram was constructed by incorporating the radiomics signature and risk factors.

STATISTICAL TESTS

Clinical-MRI characteristics were performed by a univariate analysis. Model performances (discrimination, calibration, and clinical usefulness) were validated in the external validation set. The RS-T1 model, RS-FST2 model, and RS-Combined model had an area under curves (AUCs) of 0.645, 0.641, and 0.829, respectively, in the external validation set. The radiomics nomogram, incorporating significant risk factors and the RS-Combined model had AUCs of 0.916 (95%CI, 0.866-0.966, training set) and 0.879 (95%CI, 0.791-0.967, external validation set), and demonstrated good calibration and good clinical utility.

DATA CONCLUSION

The proposed noninvasive MRI-based radiomics models showed good performance in differentiating low-grade from high-grade STSs.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY STAGE: 2.

Novel dedifferentiated liposarcoma xenograft models reveal PTEN down-regulation as a malignant signature and response to PI3K pathway inhibition

Liposarcoma is a type of soft tissue sarcoma that exhibits poor survival and a high recurrence rate. Treatment is generally limited to surgery and radiation, which emphasizes the need for better understanding of this disease. Because very few in vivo and in vitro models can reproducibly recapitulate the human disease, we generated several xenograft models from surgically resected human dedifferentiated liposarcoma. All xenografts recapitulated morphological and gene expression characteristics of the patient tumors after continuous in vivo passages. Importantly, xenograftability was directly correlated with disease-specific survival of liposarcoma patients. Thus, the ability for the tumor of a patient to engraft may help identify those patients who will benefit from more aggressive treatment regimens. Gene expression analyses highlighted the association between xenograftability and a unique gene expression signature, including down-regulated PTEN tumor-suppressor gene expression and a progenitor-like phenotype. When treated with the PI3K/AKT/mTOR pathway inhibitor rapamycin alone or in combination with the multikinase inhibitor sorafenib, all xenografts responded with increased lipid content and a more differentiated gene expression profile. These human xenograft models may facilitate liposarcoma research and accelerate the generation of readily translatable preclinical data that could ultimately influence patient care.

New therapeutic targets in soft tissue sarcoma

Soft tissue sarcomas are an uncommon and diverse group of more than 50 mesenchymal malignancies. The pathogenesis of many of these is poorly understood, but others have begun to reveal the secrets of their underlying mechanisms. With considerable effort over recent years, soft tissue sarcomas have increasingly been classified on the basis of underlying molecular alterations. In turn, this has allowed the development and application of targeted agents in several specific, molecularly defined, sarcoma subtypes. This review will focus on the rationale for targeted therapy in sarcoma, with emphasis on the relevance of specific molecular factors and pathways in both translocation-associated sarcomas and in genetically complex tumors. In addition, we will address some of the early successes in sarcoma-targeted therapy as well as a few challenges and disappointments in this field. Finally, we will discuss several possible opportunities represented by poorly understood, but potentially promising new therapeutic targets, as well as several novel biological agents currently in preclinical and early phase I/II trials. This will provide the reader with the context for understanding the current state of this field and a sense of where it may be headed in the coming years.

Intensified adjuvant IFADIC chemotherapy in combination with radiotherapy versus radiotherapy alone for soft tissue sarcoma: long-term follow-up of a prospective randomized feasibility trial

Adjuvant chemotherapy for grade 2 and 3 soft tissue sarcoma (STS) patients still has to be considered experimental. Fifty-nine patients underwent primary surgery by wide or marginal excision and were subsequently randomized to receive radiotherapy alone or in combination with six courses of chemotherapy consisting of ifosfamide, DTIC, and doxorubicin administered in 14-day intervals supported by G-CSF on days 5-13. Twenty-eight patients received radiotherapy (control group) and 31 patients were treated with additional chemotherapy. After a median observation period of 97 months (range: 13-158 months), 58 patients were followed up to assess long-term relapse-free survival (RFS), time to local failure (TLF), time to distant failure (TDF), and overall survival (OS). Fifteen patients (56%) in the control group vs. 19 patients (61%) in the chemotherapy group were free of disease. Within the control group, tumor relapses occurred in 12 patients (44%) vs. 12 patients (39%) in the chemotherapy group. RFS (P = 0.87), TLF (P = 0.58), TDF (P = 0.60) as well as OS (P = 0.99) did not differ significantly between the two groups. Adjuvant chemotherapy was not translated into a significant benefit concerning RFS, TLF, TDF, and OS for STS patients.

Endosialin: from vascular target to biomarker for human sarcomas

Biomarkers have been the focus of investigations to diagnose disease, track response to therapy and predict prognosis. Meanwhile, the identification of new targets for therapeutic intervention is an ongoing quest in the field of oncology. The recognition of endosialin as an antigen that is selectively overexpressed in human tumor tissues offers new strategies for treating cancer. Not only do the tumor vasculature and stromal compartments upregulate endosialin but, importantly, the malignant cells of sarcomas strongly express endosialin as well. A diagnostic assay that measures the intensity of endosialin expression in malignant tissues would assist in selecting patients that could benefit from an antiendosialin therapy. Thus, endosialin holds potential value both as a therapeutic target and as a biomarker for certain human cancers.

Rapamycin pharmacokinetic and pharmacodynamic relationships in osteosarcoma: a comparative oncology study in dogs

Background

Signaling through the mTOR pathway contributes to growth, progression and chemoresistance of several cancers. Accordingly, inhibitors have been developed as potentially valuable therapeutics. Their optimal development requires consideration of dose, regimen, biomarkers and a rationale for their use in combination with other agents. Using the infrastructure of the Comparative Oncology Trials Consortium many of these complex questions were asked within a relevant population of dogs with osteosarcoma to inform the development of mTOR inhibitors for future use in pediatric osteosarcoma patients.

Methodology/Principal Findings

This prospective dose escalation study of a parenteral formulation of rapamycin sought to define a safe, pharmacokinetically relevant, and pharmacodynamically active dose of rapamycin in dogs with appendicular osteosarcoma. Dogs entered into dose cohorts consisting of 3 dogs/cohort. Dogs underwent a pre-treatment tumor biopsy and collection of baseline PBMC. Dogs received a single intramuscular dose of rapamycin and underwent 48-hour whole blood pharmacokinetic sampling. Additionally, daily intramuscular doses of rapamycin were administered for 7 days with blood rapamycin trough levels collected on Day 8, 9 and 15. At Day 8 post-treatment collection of tumor and PBMC were obtained. No maximally tolerated dose of rapamycin was attained through escalation to the maximal planned dose of 0.08 mg/kg (2.5 mg/30kg dog). Pharmacokinetic analysis revealed a dose-dependent exposure. In all cohorts modulation of the mTOR pathway in tumor and PBMC (pS6RP/S6RP) was demonstrated. No change in pAKT/AKT was seen in tumor samples following rapamycin therapy.

Conclusions/Significance

Rapamycin may be safely administered to dogs and can yield therapeutic exposures. Modulation pS6RP/S6RP in tumor tissue and PBMCs was not dependent on dose. Results from this study confirm that the dog may be included in the translational development of rapamycin and potentially other mTOR inhibitors. Ongoing studies of rapamycin in dogs will define optimal schedules for their use in cancer and evaluate the role of rapamycin use in the setting of minimal residual disease.

Trabectedin in myxoid liposarcomas (MLS): a long-term analysis of a single-institution series

BACKGROUND

Trabectedin has been approved in Europe as second-line therapy for advanced soft tissue sarcomas. A previous analysis showed that myxoid liposarcomas (MLS) are particularly sensitive to the drug. We report on the long-term efficacy of trabectedin in a subgroup of that series.

METHODS

Since September 2002, 32 advanced pretreated MLS patients received trabectedin at our center. Data were reviewed focusing on their long-term outcome.

RESULTS

Trabectedin was given as a 24-h continuous infusion every 21 days. A total of 376 and a median of 12 courses per patient (range 2-26; interquartiles range (IQR) 8-15) were delivered. Response rate per RECIST was 50% [95% confidence interval (CI) 32% to 68%], median progression-free survival (PFS) was 17 months (95% CI 13.5-30.1) and median overall survival is still not reached. In 10 patients, therapy was stopped in the absence of any evident disease, mostly after complete surgery of residual lesions. In these 10 patients, at a median follow-up of 25 months, PFS was 28.1 months (95% CI 25.6-36.4) from treatment start.

DISCUSSION

These data indicate that the high response rate of MLS to trabectedin translates into prolonged PFS. Surgery of residual metastatic disease is already used quite extensively in metastatic MLS. Trabectedin may give further significance to this kind of surgery.

Endosialin protein expression and therapeutic target potential in human solid tumors: sarcoma versus carcinoma

PURPOSE

Endosialin/CD248/tumor endothelial marker 1 is expressed in stromal cells, endothelial cells, and pericytes in various tumors; however, few studies have focused on expression in malignant cells.

EXPERIMENTAL DESIGN

We studied expression of endosialin in clinical specimens, cell culture, and animal models and designed an anti-endosialin therapeutic prototype.

RESULTS

Fifty human tumor cell lines and 6 normal cell types in culture were assayed by reverse transcription-PCR and/or flow cytometry for endosialin. Cell surface protein was found on 7 sarcoma lines, 1 neuroblastoma, and 4 normal cell types in culture. A fully human anti-endosialin antibody bound to human A-673 Ewing's sarcoma cells and SK-N-AS neuroblastoma cells but not HT-1080 cells. Exposure of cells to an anti-human IgG conjugated to saporin resulted in growth inhibition only of endosialin-expressing cells. Endosialin expression was assessed by immunohistochemistry in 250 clinical specimens of human cancer including 20 cancer subtypes. Endosialin is frequently found in human cancers. Endosialin expression is mainly a perivascular feature in carcinomas, with some expression in stromal cells. In sarcomas, endosialin is expressed by malignant cells, perivascular cells, and stromal cells. Development and characterization of experimental models for studying endosialin biology in sarcomas and evaluating anti-endosialin therapies is presented.

CONCLUSIONS

Findings suggest that an anti-endosialin immunotoxin might be a promising therapeutic approach for endosialin-positive neoplasia, especially synovial sarcoma, fibrosarcoma, malignant fibrous histiocytoma, liposarcoma, and osteosarcoma. Thus, a diagnostic/therapeutic targeted therapeutic approach to treatment of endosialin-expressing tumors may be possible.

Combined vascular endothelial growth factor receptor/epidermal growth factor receptor blockade with chemotherapy for treatment of local, uterine, and metastatic soft tissue sarcoma

PURPOSE

Soft tissue sarcoma (STS) is a rare heterogeneous malignancy. Overall survival has been stagnant for decades, primarily because systemic therapies are ineffective versus metastases, the leading cause of STS lethality. Consequently, we examined whether tyrosine kinase receptors active in STS growth signaling might be blockable and whether multireceptor blockade might synergize with low-dose STS chemotherapy by therapeutically affecting STS cells and their associated microenvironment.

EXPERIMENTAL DESIGN

Vandetanib (AstraZenca), a tyrosine kinase inhibitor of vascular endothelial growth factor receptor 2 and epidermal growth factor receptor, was evaluated alone and with chemotherapy in vitro and in vivo in three human STS nude mouse xenograft models of different STS locations (muscle, uterus, lung), stages (primary, metastatic), and subtypes (leiomyosarcoma, fibrosarcoma, uterine sarcoma: luciferase-expressing MES-SA human uterine sarcoma cells surgically implanted into uterine muscularis with bioluminescence tumor growth assessment; developed by us).

RESULTS

In vitro, human STS cells were sensitive to vandetanib. Vandetanib alone and with chemotherapy statistically significantly inhibited leiomyosarcoma local growth and fibrosarcoma lung metastasis. Direct injection of MES-SA into nude mice uterine muscularis resulted in high tumor take (88%), whereas s.c. injection resulted in no growth, suggesting microenvironmental tumor growth modulation. Vandetanib alone and with chemotherapy statistically significantly inhibited uterine sarcoma growth. In all models, vandetanib induced increased apoptosis, decreased tumor cell proliferation, and decreased angiogenesis.

CONCLUSIONS

Vandetanib has antitumor effects against human STS subtypes in vitro and in vivo, where it also affects the tumor-associated microenvironment. Given the urgent need for better systemic approaches to STS, clinical trials evaluating vandetanib, perhaps with low-dose chemotherapy, seem warranted.

Clinical impact of trabectedin (ecteinascidin-743) in advanced/metastatic soft tissue sarcoma

BACKGROUND

Patients with advanced or metastatic non-gastrointestinal stromal tumour soft tissue sarcoma (STS) whose disease progresses during or after chemotherapy with doxorubicin or ifosfamide have few options and very limited life expectancy. In this setting, the DNA and transcription interacting agent trabectedin (ecteinascidin-743), isolated originally from the tunicate Ecteinascidia turbinata, has encouraging activity and is now approved in the European Union.

OBJECTIVE

To review evidence for the efficacy of trabectedin in STSs.

METHODS

This review includes material known to the authors through preclinical and clinical work with trabectedin, and information from relevant papers and abstracts.

RESULTS

Pooled analysis of Phase II studies suggests that around 50% of STS patients, failing conventional chemotherapy, experienced long lasting tumour control (either objective response or stabilization of disease) when treated with trabectedin. Twenty-nine per cent of patients were alive at 2 years, and median overall survival was 10.3 months. Leiomyosarcomas and liposarcomas appear particularly sensitive to the drug. In myxoid and round-cell liposarcomas trabectedin seems exceptionally active. A link between specific translocations underlying this disease and the drug's mechanism of action is being explored. Trabectedin is also active in synovial, ewing sarcoma and other translocation-related STSs. Trabectedin is not cardio- or neurotoxic. The neutropenia and hepatic toxicity that occur are non-cumulative, reversible, and lessened by steroid premedication. The lack of cumulative toxicities could make trabectedin appropriate for prolonged treatment.

CONCLUSION

The potential of trabectedin should be further explored in STSs in general and in specific subtypes, both in combination with other cytotoxic agents and with modulators of intracellular signalling.

Trabectedin : a review of its use in the management of soft tissue sarcoma and ovarian cancer

Trabectedin (Yondelis); ET-743) is an antineoplastic agent that was originally derived from the Caribbean marine tunicate Ecteinascidia turbinata and is now produced synthetically. It binds to the minor groove of DNA, disrupting the cell cycle and inhibiting cell proliferation. Intravenous trabectedin administered once every 3 weeks is approved as monotherapy in Europe for use in patients with advanced soft tissue sarcoma (STS) after failure of standard therapy with anthracyclines or ifosfamide, or who are unsuited to receive these agents. It also has orphan drug status in STS in the US and in ovarian cancer in the US and Europe, and is under investigation as combination therapy in patients with recurrent ovarian cancer. In clinical trials, trabectedin showed efficacy in the treatment of patients with advanced or metastatic STS, especially those with leiomyosarcoma or liposarcoma, as well as in women with platinum-sensitive advanced or recurrent ovarian cancer. In addition, its tolerability profile was generally manageable. The introduction of trabectedin expands the currently limited range of effective treatment options for patients with advanced or metastatic STS; trabectedin also has the potential to be a beneficial treatment for advanced or recurrent ovarian cancer.