Title: EORTC-1809-STBSG: A randomized phase III study of neoadjuvant chemotherapy followed by surgery versus surgery alone for patients with High Risk RetroPeritoneal Sarcoma (STRASS 2)
Funder: Cancer Research UK

Abstract: Title STRASS 2 (1809-STBSG): A randomized phase III study of neoadjuvant chemotherapy followed by surgery versus surgery alone for patients with High Risk RetroPeritoneal Sarcoma (STRASS 2) Background Retroperitoneal sarcomas account for 15% of soft-tissue sarcomas. Current standard of care consists of surgery alone. High-grade retroperitoneal dedifferentiated liposarcoma and leiomyosarcoma have a risk of metastatic recurrence and death of 70% at 5 yrs. Systemic chemotherapy may address the metastatic risk and improve relapse-free and overall survival. Neoadjuvant chemotherapy is preferable for a study in this disease, to assess drug activity and efficacy, study tumour biology and response to therapy, and immediately address the systemic risk. No formal study looking for a possible benefit of chemotherapy in these patients has previously been performed. Aims The primary objective of this study is to assess whether preoperative chemotherapy with curative-intent surgery, improves the prognosis of patients with high risk de-differentiated liposarcoma and leiomyosarcoma as measured by disease-free survival. Events are distant progression on neoadjuvant treatment, local progression not followed by surgery, non-operable tumours, local recurrence and/or distant metastases, R2 and death. Secondary research objectives • To assess a difference in the overall survival, recurrence-free survival, distant metastases-free survival, cumulative incidence of local recurrences and distant metastases • To assess tumour response and toxicity profile in patients undergoing preoperative chemotherapy • To assess whether there is a difference in quality of life between patients undergoing curative-intent surgery alone and those undergoing preoperative chemotherapy followed by curative intent surgery. Methods This is a randomised, multicentre, open-label phase III trial of neoadjuvant chemotherapy followed by surgery versus surgery alone in patients with RPS. The randomisation will be stratified by institution and histology: liposarcoma or leiomyosarcoma. Patients will be randomised to either Standard arm: curative intent surgery alone or the experimental arm: 3 cycles of neoadjuvant chemotherapy followed by curative intent surgery after chemotherapy. For liposarcomas doxorubicin and ifosfamide will be used while for leiomyosarcoma doxorubicin and dacarbazine will be used. How the results of this research will be used. The study will provide high-level randomised evidence to direct future standard treatment for high-grade retroperitoneal sarcomas. Translational research will evaluate molecular tumour characteristics and immune-related features relevant to response to establish predictive factors for neoadjuvant response and new prognostic factors, correlation of pathology and imaging features and evaluation of radiomics approach for prediction of clinical outcome. Quality of Life to test for for equivalence at month 12th.


Research activity codes: 6.1 PHARMACEUTICALS;6.4 SURGERY
Health categories: CANCER AND NEOPLASMS