Soft tissue sarcomas [STSs] are rare tumors of mesodermal origin that arise in diverse tissues such as muscles, fat, and nerves. There are over 100 subtypes of STS, each with distinct clinical behaviors and responses to treatment. Recent advances in treatment have moved towards histology-specific approaches, emphasizing the integration of pathological, immunohistochemical, and molecular features to guide treatment. Localized STS is primarily treated with surgery, often supplemented by neoadjuvant or adjuvant radiation and/or chemotherapy. However, about half of patients with localized disease will progress to an advanced stage, which is typically managed with systemic therapies including anthracycline-based chemotherapy such as doxorubicin or epirubicin. Despite these treatments, the survival rates for most subtypes of advanced metastatic STS remain relatively low. While anthracycline-based chemotherapy remains the mainstay of treatment, ongoing research into the biology of STSs is enhancing our understanding and approach to these complex tumors with an expansion beyond chemotherapy to include targeted therapy and immunotherapy to improve response rates and survival outcomes. This review focuses on STS other than gastrointestinal stromal tumors [GISTs], examines the current systemic treatment strategies, highlights recent advances, and explores future directions in the systemic therapy of sarcoma patients.

High-dose melphalan-based autologous stem cell transplant (ASCT) remains a standard of care for plasma cell disorders (PCDs). Currently, there is variability in the literature surrounding the timing of melphalan administration to avoid potential cytotoxic effects, although the administration has been safely proposed when given at least 8 hours prior to stem cell infusion. The objectives of this study were to assess differences in safety and efficacy outcomes between day -1 and day -2 single-dose melphalan administration in patients undergoing ASCT for PCDs. A retrospective chart review was performed at our institution comparing patients receiving melphalan on day -1 to an equal number of patients receiving melphalan on day -2. The primary endpoint was time to neutrophil engraftment from stem cell infusion. Univariate analyses were performed. Mean time to neutrophil engraftment from stem cell infusion was identical at 10.7 days for both cohorts ( p = 0.88). Mean time to platelet engraftment from stem cell infusion was shorter with day -1 administration (17.4 vs. 18.6 days, p = 0.06). Mean time to neutrophil and platelet engraftment from melphalan infusion were significantly shorter with day -1 administration. Similar outcomes were observed for length of hospitalization, infection- and mucositis-related toxicities, hematologic response, transplant-related mortality, and overall survival. Our findings show no difference in time to neutrophil engraftment from stem cell infusion and a trend toward shorter time to platelet engraftment with day -1 administration. Based on our study, day -1 melphalan administration is an acceptable and safe practice.

The combination of targeted therapies and immunotherapies for advanced and metastatic sarcomas has been proposed owing to the enhanced effect of antiangiogenic therapies on the tumor microenvironment. We found eight studies published to date assessing the effectiveness of combined multitargeted vascular endothelial growth factor (VEGF)–tyrosine kinase inhibitors with immune checkpoint inhibitors (ICIs) in sarcoma. It is difficult to draw conclusions owing to limited data and primarily single-arm studies, although initial literature appears promising and requires further study. It remains unknown which sarcoma subtypes may derive the most benefit owing to the limited literature. Benefit was seen primarily in angiosarcoma (AS) and alveolar soft part sarcoma (ASPS), as well as in other tumor subtypes, with few patients achieving complete response (CR). The patients who achieved CRs had desmoplastic small round cell tumor (DSRCT), AS, and chondrosarcoma (CS). Mixed results were found in patients with leiomyosarcoma (LMS), gastrointestinal stromal tumor (GIST), and bone sarcomas, although combination therapy appears to be less effective in these subtypes. Further studies are required to explore optimal treatment agents and dosing strategies to improve both efficacy and tolerability. Although initial results are promising in select patients, phase 3 randomized controlled trials are necessary to determine true treatment effect with combination therapy versus VEGF-inhibitor or ICI alone.