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.

Background: The prognostic value of treatment-induced necrosis in soft STS remains uncertain. This study evaluated whether MRI-based changes in necrosis (Δ necrosis) between pre- and post-neoadjuvant chemotherapy scans correlate with pathologic necrosis and clinical outcomes. Methods: In this retrospective cohort, 27 patients with STS who received neoadjuvant chemotherapy and underwent pre- and post-treatment MRI were analyzed. Necrosis was graded categorically (95%), and Δ necrosis was calculated as the change in estimated necrosis between scans. Correlations between MRI-derived and pathologic necrosis were assessed using Spearman’s rank coefficient. Survival analyses (progression-free, local recurrence-free, and disease-specific overall survival) were performed using Kaplan–Meier and log-rank tests. Results: Post-treatment MRI necrosis moderately correlated with pathologic necrosis (ρ = 0.44, p = 0.028), whereas Δ necrosis showed a weaker, nonsignificant correlation (ρ = 0.24, p = 0.24). Neither MRI-based nor pathologic necrosis thresholds were associated with survival outcomes. Conclusions: MRI-based Δ necrosis did not predict pathologic necrosis or oncologic outcomes in STS, suggesting that radiologic changes in necrosis may not serve as reliable markers of therapeutic response. Future studies integrating quantitative imaging and standardized pathology protocols together with future exploration of molecular tools such as ctDNA are needed to refine treatment assessment in STS.