The role of ifosfamide-doxorubicin chemotherapy in the treatment histology-specific, high grade, locally advanced soft tissue sarcoma: A 14-year experience.

Abstract

e23529 Background: To compare long-term outcomes of high grade, locally advanced, primary soft tissue sarcoma (STS), using Ifosfamide-Doxorubicin vs local therapy alone, in histology-specific sarcomas. Methods: Retrospective analysis was performed on 127 patients from 2005 to 2018, who had STS of extremity or trunk, > 5cm, that were either Synovial Cell, Dedifferentiated Liposarcoma (DDL), Myxofibrosarcoma, Round Cell Liposarcoma (RCLS), Undifferentiated Pleomorphic Sarcoma (UPS), or Undifferentiated Sarcoma not otherwise specified (NOS), with central pathology review. Ifosfamide-doxorubicin was generally given neoadjuvant, followed by radiation and wide excision, with chemotherapy given in 38 patients, while 89 received local therapy alone. Multi-variable analysis of prognostic factors was performed, and local-recurrence-free-survival (LRFS), distant-metastases-free-survival (DMFS), disease-specific-survival (DSS), and overall-survival(OS) were estimated using Kaplan-Meier. Results: Median follow-up was 4.5 years. Younger age (p < 0.0001) and Synovial histology (p = 0.0002) had significantly higher rates of receiving chemotherapy. Size > 10cm and trunk location were poor prognostic features on multivariable analysis (MVA) affecting DMFS, DSS, and OS, while DDL histology had a more favorable effect; although size, trunk location, and DDL histology were not significantly different between treatment groups. Ifosfamide-Doxorubicin vs local therapy alone improved 5-year DMFS at 70.2% vs 49.5% ,p = 0.02, DSS 83.5% vs 57.9%, p = 0.009, and OS 80.6% vs 53.8%, p = 0.002. Sub-analysis of non-synovial histologies still showed a significant improvements in favor of chemotherapy in DMFS,(p = 0.04), DSS (p = 0.02), and OS (p = 0.003). Conclusions: Ifosfamide-Doxorubicin chemotherapy benefits younger patients with > 5cm, high grade, STS of the trunk or extremity, with histologies of Synovial Cell, DDL, Myxofibrosarcoma, RCLS, UPS, or Undifferentiated Sarcoma NOS.