Molecular targeted therapies in non-GIST soft tissue sarcomas: what the radiologist needs to know

Primary myxoid liposarcoma of the pelvis: An unusual location

Myxoid liposarcoma is the second most common type of liposarcoma, normally located in deep tissues of the lower extremities and rarely in the mesenchyma of abdomen and pelvis We present a patient who, incidentally, showed a large pelvis mass. CT and MR revealed a loculated lesión with hypodense areas and very high signal in T2 respectively as well as heterogeneous contrast enhancement. The imaging findings of pelvic myxoid liposarcoma are nonspecific, but nevertheless a painless mesenchymal mass should be considered when we see lesions of myxoid aspect in the pelvic area without a clear relationship with defined anatomic structures.

Hallmarks of Cancer in the Reading Room: A Guide for Radiologists

OBJECTIVE

The hallmarks of cancer are mechanisms that cells develop to undergo malignant transformation. The targeting of these hallmarks by newer cancer therapies results in new mechanisms of response, toxicity, and resistance. The purpose of this article is to review these hallmarks, their associated targeted therapies, imaging features of responses, and toxicities.

CONCLUSION

Ten hallmarks, among them proliferative signaling, angiogenesis, immune response, and genome instability, are reviewed. Molecular targeted therapies, including antiangiogenic factors and immune checkpoint inhibitors, target these hallmarks.

Current Concepts in Non-Gastrointestinal Stromal Tumor Soft Tissue Sarcomas: A Primer for Radiologists

Non-gastrointestinal stromal tumor (GIST) soft tissue sarcomas (STSs) are a heterogeneous group of neoplasms whose classification and management continues to evolve with better understanding of their biologic behavior. The 2013 World Health Organization (WHO) has revised their classification based on new immunohistochemical and cytogenetic data. In this article, we will provide a brief overview of the revised WHO classification of soft tissue tumors, discuss in detail the radiology and management of the two most common adult non-GIST STS, namely liposarcoma and leiomyosarcoma, and review some of the emerging histology-driven targeted therapies in non-GIST STS, focusing on the role of the radiologist.

Soft-Tissue Sarcomas: An Update for Radiologists Based on the Revised 2013 World Health Organization Classification

OBJECTIVE

Soft-tissue sarcomas are a diverse group of malignancies, and our rapidly improving understanding of their molecular pathogenesis and treatment is leading to better clinical outcomes. The revised 2013 World Health Organization (WHO) classification of soft-tissue sarcomas introduced several important changes. We provide a comprehensive overview of the relevant changes for radiologists.

CONCLUSION

Rapid advances in the understanding of the pathogenesis and molecular biology of soft-tissue sarcomas led to major revisions in the 2013 WHO classification. To provide optimal multidisciplinary patient care, radiologists must remain up-to-date with the latest developments in the field of soft-tissue sarcomas to best correlate the histologic and imaging features of the various types of tumors and understand the unique patterns of treatment response and disease recurrence.

Preoperative radiotherapy for extremity soft tissue sarcoma; past, present and future perspectives on dose fractionation regimens and combined modality strategies

INTRODUCTION

This critical review aims to summarize published data on limb sparing surgery for extremity soft tissue sarcoma in combination with pre-operative radiotherapy (RT).

METHODS

This review is based on peer-reviewed publications using a PubMed search on the MeSH headings "soft tissue sarcoma" AND "preoperative radiotherapy". Titles and abstracts screened for data including "fraction size AND/OR total dose AND/OR overall treatment time", "chemotherapy", "targeted agents AND/OR tyrosine kinase inhibitors", are collated. Reference lists from some articles have been studied to obtain other pertinent articles. Additional abstracts presented at international sarcoma meetings have been included as well as information on relevant clinical trials available at the ClinicalTrials.gov website.

RESULTS

Data are presented for the conventional regimen of 50-50.4Gy in 25-28 fractions in 5-6 of weeks preoperative external beam RT with respect to the regimen's local control probability compared to surgery alone, as well as acute and late toxicities. The rationale and outcome data for hypofractionated and/or reduced dose regimens are discussed. Finally, combination schedules with conventional chemotherapy and/or targeted agents are summarized.

CONCLUSION

Outside the setting of well-designed prospective clinical trials, the conventional 50Gy in 5-6week schedule should be considered as standard. However, current and future studies addressing alternative fraction size, total dose, overall treatment time and/or combination with chemotherapy or targeted agents may reveal regimens of equal or increased efficacy with reduced late morbidities.

Current and advancing systemic treatment options for soft tissue sarcomas

INTRODUCTION

Soft tissue sarcomas are a collection of rare malignancies, the treatment of which has evolved over time. Although cytotoxic chemotherapy remains the cornerstone of management of metastatic disease, many new treatments have been developed or show great promise in the treatment of soft tissue sarcoma. Research into the different underlying pathogenesis of individual subtypes has driven progress in treatment. This has allowed development of treatments targeted to specific subtypes of sarcoma.

AREAS COVERED

We provide a review of the current field of systemic therapy in soft tissue sarcoma. This is followed by an in-depth analysis of recent developments in treatment, as well as new treatments that are aimed at specific subtypes of sarcoma, and the biological rationale behind these therapies. We also look in detail at the promising new agents currently in development.

EXPERT OPINION

Much progression has been made in treatment of soft tissue sarcomas with multiple exciting new treatments in development. However outcomes in general remain poor. Further research into the underlying pathogenesis of soft tissue sarcomas may help deliver more effective systemic therapies. Increased collaboration between basic science, translational and clinical investigators is required at national and international levels to maximise progress.

Reversion of Hormone Treatment Resistance with the Addition of an mTOR Inhibitor in Endometrial Stromal Sarcoma

Background. Endometrial stromal sarcomas (ESS) are a subtype of gynaecological sarcomas characterized by the overexpression of hormone receptors. Hormone treatment is widely used in ESS but primary or acquired resistance is common. The mammalian target of rapamycin (mTOR) pathway has been suggested to play a key role in the mechanisms of hormone resistance. Recent studies in breast and prostate cancer demonstrate that this resistance can be reversed with the addition of an mTOR inhibitor. This phenomenon has never been reported in ESS. Methods. We report the outcome of one patient with pretreated, progressing low grade metastatic ESS treated with medroxyprogesterone acetate in combination with the mTOR inhibitor sirolimus. Results. Partial response was achieved following the addition of sirolimus to the hormone treatment. Response has been maintained for more than 2 years with minimal toxicity and treatment is ongoing. Conclusion. This case suggests that the resistance to the hormone manipulation in ESS can be reversed by the addition of an mTOR pathway inhibitor. This observation is highly encouraging and deserves further investigation.

MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas: experience in 47 patients

OBJECTIVE

To describe MRI, MDCT features, and clinical outcome of extremity leiomyosarcomas (LMS).

MATERIALS AND METHODS

In this IRB-approved, HIPAA-compliant retrospective study, we included 47 patients (23 women, 24 men; mean age: 55.3 years, range: 17-85 years) with pathologically confirmed extremity LMS seen at our adult tertiary cancer center between 2000 and 2012. MRI/MDCT of primary tumors in 23 patients and follow-up in all patients were reviewed by two radiologists in consensus. Clinical data were extracted from electronic medical records.

RESULTS

Primary tumors were distributed in bones (6 out of 47), deep soft tissues (24 out of 47), and superficial soft tissues (17 out of 47). On imaging (bone = 4, deep soft tissue = 11, superficial soft tissue = 8), compared with skeletal muscle, they were T1 iso-hypointense and T2 hyperintense. Bone LMS were metaphyseal tumors with cortical destruction (3 out of 4). Deep soft-tissue LMS were large with hemorrhage (7 out of 11) and necrosis (10 out of 11). Superficial soft-tissue LMS were relatively smaller, homogeneously enhancing (6 out of 8) tumors. Distant metastases developed in 32 out of 47 patients (bone LMS [6 out of 6], deep soft-tissue LMS [18 out of 24], superficial soft-tissue LMS [8 out of 17]), commonly to lung (29 out of 47) and bone (14 out of 47). At the time of writing, 22 out of 36 patients (bone LMS [4 out of 6], deep soft-tissue LMS [15 out of 24], superficial soft-tissue LMS [4 out of 17]) have died. There was no statistically significant correlation between metastatic disease and tumor size or grade.

CONCLUSION

Extremity LMS arise in bones and in the deep and superficial soft tissues, frequently metastasize to the lungs, and have a poor prognosis. Superficial LMS tend to have a better prognosis than bone or deep soft-tissue LMS.

Multimodality imaging features, metastatic pattern and clinical outcome in adult extraskeletal Ewing sarcoma: experience in 26 patients

OBJECTIVE

To describe the multimodality imaging features, metastatic pattern and clinical outcome in adult extraskeletal Ewing sarcoma (EES).

METHODS

In this institutional review board-approved, health insurance portability and accountability act-compliant retrospective study, we included 26 patients (17 females and 9 males; mean age, 36 years; range, 18-85 years) with pathologically confirmed EES seen at our institute between 1999 and 2011, who had imaging of primary tumour. Imaging of primary tumour in all 26 patients and follow-up imaging in 23 was reviewed by two radiologists in consensus. Clinical data were extracted from electronic medical records.

RESULTS

The most common primary sites were the torso (n = 13), extremities (n = 10) and head and neck (HN) region (n = 3). The mean tumour size was 9 cm (range, 3-22 cm); tumours of the torso were larger than those of other areas (p > 0.05). Compared with the skeletal muscle, tumours were isodense on CT (21/21), hypointense (n = 5) to isointense (n = 14) on T1 weighted image, hyperintense on T2 weighted image (19/19) and were fluorine-18 fludeoxyglucose ((18)F-FDG)-avid [10/10; mean maximum standardized uptake value of 7 (range, 3-11)]. Necrosis (15/26), haemorrhage (5/26) and adjacent organ invasion (14/26) were present without calcification. Median follow-up was 16 months. 5 patients had local recurrence (torso, 3; extremity, 1; and HN, 1). Metastases developed in 11 patients (torso, 7; extremities, 3; and HN, 1; p > 0.05); 8 at presentation, most commonly to lung (9/11), peritoneum (4/11), muscles (4/11) and lymph nodes (4/11). Nine patients (torso, 7; extremity, 1; and HN, 1) died (10 months median survival) (p > 0.05).

CONCLUSION

Adult EESs are large tumours, which frequently invade adjacent organs and metastasize to the lung. EESs of the torso are larger, have more frequent metastases and poorer outcomes.

ADVANCES IN KNOWLEDGE

Adult EESs of the torso have poor outcomes compared with other EESs.

Imaging features of primary and metastatic alveolar soft part sarcoma: single institute experience in 25 patients

OBJECTIVE

To describe imaging features of primary and metastatic alveolar soft part sarcoma (ASPS).

METHODS

In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant retrospective study, 25 patients (14 males; mean age, 25 years; range, 18-40 years) with pathologically proven ASPS seen at our institute between 1995 and 2013 were included. Imaging of primary tumours in 5 patients and follow-up imaging in 25 patients were reviewed by 2 radiologists in consensus. Clinical information was obtained from electronic medical records.

RESULTS

The most common sites for the primary tumour were extremities (17/25, 68%) and torso (6/25, 24%). Primary tumours (n = 5) were well circumscribed, compared with skeletal muscle, were isodense on CT, hyperintense on T1 and T2 weighted images with intense post-contrast enhancement, prominent feeders on CT and flow voids on MRI. Metastases developed in 23/25 (92%) patients, 18 at presentation. The most common sites of metastases were the lungs (100%), lymph nodes (74%), bones (57%) and brain (43%). Visceral and nodal metastases were hypervascular. At the time of reporting the results, 15 patients have died, 6 are alive and 4 were lost to follow-up. Median survival was 74 months for those without brain metastases (n = 8) and 60 months for those with brain metastases (n = 7). Median survival was shorter for patients with metastases at presentation.

CONCLUSION

ASPS most commonly involves the lower extremities of young adults, is hypervascular on imaging, often metastasizes at presentation, frequently to lung, nodes, bones and brain, and has an indolent course despite metastases. Brain metastases and high tumour burden (number of metastatic sites) at presentation decreased survival in our study.

ADVANCES IN KNOWLEDGE

ASPS has an unusual pattern of metastases to the brain and nodes in addition to lung and bones. It has an indolent course despite metastases.