Durable clinical activity of single-agent bevacizumab in a nonagenarian patient with metastatic alveolar soft part sarcoma

Advances in treatment of alveolar soft part sarcoma: an updated review

Alveolar soft part sarcoma is a rare neoplasm of uncertain histogenesis that belongs to a newly defined category of ultra-rare sarcomas. The neoplasm is characterized by a specific chromosomal translocation, der (17) t(X; 17)(p11.2;q25), that results in ASPSCR1-TFE3 gene fusion. The natural history of alveolar soft part sarcoma describes indolent behaviour with slow progression in deep soft tissues of the extremities, trunk and head/neck in adolescents and young adults. A high rate of detection of distant metastasis at presentation has been reported, and the most common metastatic sites in decreasing order of frequency are the lung, bone and brain. Complete surgical resection remains the standard treatment strategy, whereas radiotherapy is indicated for patients with inadequate surgical margins or unresectable tumours. Although alveolar soft part sarcoma is refractory to conventional doxorubicin-based chemotherapy, monotherapy or combination therapy using tyrosine kinase inhibitors and immune checkpoint inhibitors have provided antitumor activity and emerged as new treatment strategies. This article provides an overview of the current understanding of this ultra-rare sarcoma and recent advancements in treatments according to the clinical stage of alveolar soft part sarcoma.

Long-term Results of Therapy with Sunitinib in Metastatic Alveolar Soft Part Sarcoma

Background

Alveolar soft part sarcoma (ASPS) is a rare, highly vascularized soft tissue sarcoma characterized by a high frequency of metastatic disease and resistance to classical chemotherapy. The purpose of our analysis was to assess long-term sunitinib activity in the treatment of metastatic ASPS.

Patients and Methods

Between 2009 and 2015, 15 patients were diagnosed with metastatic ASPS and received therapy with sunitinib at initial continuous daily dosing of 37.5 mg. Median age was 32 years. The primary tumor sites were lower extremities ( 8 ), trunk-retroperitoneum/pelvis ( 2 ), upper extremity ( 3 ) and other ( 2 ). All patients had unresectable disease (primary or relapse in the form of metastases to the lungs ± bones). Five patients received systemic therapy before initiating sunitinib. Median follow-up from start of sunitinib was 38 months (range 5-69 months).

Results

At the time of analysis 4 patients continue therapy and 9 are still alive. Six patients had RECIST partial remission as best response, 8 had stable disease, and 1 had disease progression. The median progression-free survival was 19 months, with 86% of patients being free of progression at 6 months. Median overall survival was 56 months; the 5-year overall survival rate was 49%. Five patients were treated with sunitinib longer than 2 years. All patients experienced some side effects: 8 patients (53%) had CTCAE grade 3/4 toxicity, 7 patients required dose reduction. The most common toxicities were neutropenia, thrombocytopenia, hypothyroidism, arterial hypertension, and hand-foot syndrome.

Conclusions

Our analysis confirms the long-term efficacy of sunitinib in patients with advanced ASPS.

Newer medical therapies for metastatic soft tissue sarcoma

Metastatic/advanced soft tissue sarcoma has a poor prognosis conventionally, treatment options have been limited. In recent years, this area has been a rich ground for research with many new drugs being approved and several more in the pipeline. With multiple new treatment options available, it is vital to keep up pace with this rapidly changing field. Areas covered: Recent data regarding use of novel agents in advanced soft tissue sarcoma is reviewed with a focus on clinical applicability. The goal is to guide the clinician into choosing appropriate lines of therapy for the individual patient in light of recent availability of multiple new treatment options. Expert commentary: Patients with advanced soft tissue sarcoma can expect to receive several lines of therapy in the modern era. Tumor histology should ideally guide the choice of therapy. The new FDA approved second line drugs viz, trabectedin, pazopanib and eribulin should be considered first after failure of doxorubicin-based chemotherapy. Additional options have become available, such as antiangiogenic agents, mTOR inhibitors, and several new molecules targeting specific oncogenic pathways. All these agents have a role in treating soft tissue sarcoma, and careful individualization of therapy can help achieve optimal outcomes in these challenging patients.

Frequent expression of human leukocyte antigen class I and the status of intratumoral immune cells in alveolar soft part sarcoma

The prognosis of alveolar soft part sarcoma is poor, despite the slow growth of the tumor. A number of cases with spontaneous regression of this rare tumor have been reported. Although the mechanisms underlying spontaneous regression remain uncertain, local immune reaction may be a possible contributing factor. Immunohistochemical expression of human leukocyte antigen (HLA) class I, cluster of differentiation (CD) 3, CD4, CD8, CD20, CD45, CD56, CD68, CD138 and CD163 were assessed in a series of 10 alveolar soft part sarcomas, and the expression profiles were associated with patients' clinicopathological parameters. Expression of HLA class I was observed in almost all the tumor cells of all cases. CD8(+) cells were identified in all tumors with varying densities. Moderate infiltration of CD8(+) cells was detected in three patients; one of these patients survived with long-term tumor remission. Infiltration of CD10(+), CD20(+), CD56(+) or CD138(+) cells was not revealed in all tumors. Moderate-diffuse infiltration of CD163(+) cells was observed in all tumors. To the best of our knowledge, the present study represents the first report of intratumoral immune cells in alveolar soft part sarcoma. Frequent expression of HLA class I in tumor cells was observed. CD8(+) cells were identified at various densities and CD163(+) cells were observed in alveolar soft part sarcoma. Moderate infiltration of CD8(+) cells in patients with a good prognosis may indicate the antitumor effects of immune cells in alveolar soft part sarcoma.

Metastatic Alveolar Soft Part Sarcoma Responsive to Pazopanib after Progression through Sunitinib and Bevacizumab: Two Cases

Alveolar soft part sarcoma (ASPS) is a rare soft tissue sarcoma with a propensity for lung metastases and indolent progression. ASPS is not responsive to chemotherapy, but there are case reports and small series describing benefit from drugs targeting the VEGF pathway. These drugs include sunitinib, cediranib and bevacizumab. There is no established second-line treatment for persons with ASPS progressing through first-line targeted therapy. We report two individuals with metastatic ASPS who obtained disease stabilization from sunitinib lasting over a year. After subsequent progression through sunitinib and second-line bevacizumab, both individuals again had disease response and subsequent stabilization from pazopanib.

Treatment of Metastatic, Refractory Alveolar Soft Part Sarcoma: Case Reports and Literature Review of Treatment Options in the Era of Targeted Therapy

BACKGROUND

Alveolar soft part sarcoma is a rare soft tissue sarcoma that is characterized by a pattern of slow growth with metastases to the lung, bone, and brain that is not responsive to conventional cytotoxic chemotherapy.

OBSERVATIONS

We describe 2 patients, with a combined 19 years of treatment experience including multiple different chemotherapeutic and targeted therapy regimens, surgery, and radiotherapy. We also present a review of the literature regarding treatment options to highlight recent findings.

CONCLUSIONS

Alveolar soft part sarcoma is an indolent, but persistently progressive disease. Novel therapeutic agents hold promise in its management.

Modulation of the myeloid compartment of the immune system by angiogenic- and kinase inhibitor-targeted anti-cancer therapies

Targeted therapies were rationally designed to inhibit molecular pathways in tumor cells critically involved in growth and survival; however, many drugs used in targeted therapies may affect the immune system. In addition, selected conventional chemotherapeutic agents have also been reported to be endowed with direct or indirect effects on immunity, for instance via immunogenic death of tumors. Thus, cancer therapies may have off-target effects, some of which are directed to the immune system. Here, we will review some of these effects in specific therapeutic approaches. We will examine the modulation of the immune contexture in human sarcoma and melanoma induced by anti-angiogenic therapies and by BRAF inhibitors, respectively. We will then discuss how the anti-tumor agent trabectedin is selectively cytotoxic to cells of the monocytic-macrophage lineage and how these immune-related effects can be part of the response to treatment.

Genetics of rare mesenchymal tumors: implications for targeted treatment in DFSP, ASPS, CCS, GCTB and PEComa

Soft tissue and bone sarcomas comprise a heterogeneous group of mesenchymal tumors that include roughly 130 distinct diagnostic entities. Many of them are exceptionally rare, with only few cases diagnosed worldwide each year. Development of novel targeted treatment in this group of tumors is of special importance since many sarcoma subtypes are resistant to conventional chemotherapy and the effective therapeutic options are limited. In this review we aim to discuss the molecular implications for targeted therapy in selected rare soft tissue and bone sarcoma subtypes, including dermatofibrosarcoma protuberans (DFSP), alveolar soft part sarcoma (ASPS), clear cell sarcoma (CCS), giant cell tumor of bone (GCTB) and perivascular epithelioid cell neoplasms (PEComas). This article is part of a Directed Issue entitled: Rare cancers.