Preoperative Radiotherapy in Patients With Primary Retroperitoneal Sarcoma: EORTC-62092 Trial (STRASS) Versus Off-trial (STREXIT) Results

Dario Callegaro; Chandrajit P Raut; Taiwo Ajayi; Dirk Strauss; Sylvie Bonvalot; Deanna Ng; Eberhard Stoeckle; Mark Fairweather; Piotr Rutkowski; Winan J van Houdt; Hans Gelderblom; Claudia Sangalli; Andrew Hayes; Charles Honoré; Rebecca A Gladdy; Magali Fau; Rick Haas; Dimitri Tzanis; Aisha B Miah; Peter Chung; Elizabeth H Baldini; Sandrine Marreaud; Saskia Litiere; Carol J Swallow; Alessandro Gronchi

doi:10.1097/SLA.0000000000005492

Preoperative Radiotherapy in Patients With Primary Retroperitoneal Sarcoma: EORTC-62092 Trial (STRASS) Versus Off-trial (STREXIT) Results

Ann Surg. 2023 Jul 1;278(1):127-134. doi: 10.1097/SLA.0000000000005492. Epub 2022 Jul 14.

Authors

Dario Callegaro¹, Chandrajit P Raut², Taiwo Ajayi³, Dirk Strauss⁴, Sylvie Bonvalot⁵, Deanna Ng^{6

7}, Eberhard Stoeckle⁸, Mark Fairweather², Piotr Rutkowski⁹, Winan J van Houdt¹⁰, Hans Gelderblom¹¹, Claudia Sangalli¹², Andrew Hayes⁴, Charles Honoré¹³, Rebecca A Gladdy⁶, Magali Fau⁷, Rick Haas^{14

15}, Dimitri Tzanis⁵, Aisha B Miah¹⁶, Peter Chung^{17

7}, Elizabeth H Baldini¹⁸, Sandrine Marreaud¹⁹, Saskia Litiere³, Carol J Swallow⁶, Alessandro Gronchi¹

Affiliations

¹ Department of Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
² Department of Surgery, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA.
³ Department of Statistics, European Organisation for Research and Treatment of Cancer, Brussels, Belgium.
⁴ Department of General Surgery, Royal Marsden NHS Foundation Trust, London, UK.
⁵ Department of Surgery, Institute Curie, University of Paris, Paris, France.
⁶ Department of Surgical Oncology, Princess Margaret Cancer Center/Mount Sinai Hospital, Toronto, ON, Canada.
⁷ Department of Surgery, University of Toronto, Toronto, ON, Canada.
⁸ Department of Surgery, Institut Bergonie, Bordeaux, France.
⁹ Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland.
¹⁰ Department of Surgical Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
¹¹ Department of Medical Oncology, Leiden University Medical Center, Leiden, The Netherlands.
¹² Department of Radiation Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
¹³ Department of Surgical Oncology, Institut Gustave Roussy, Villejuif, France.
¹⁴ Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
¹⁵ Department of Radiotherapy, Leiden University Medical Center, Leiden, The Netherlands.
¹⁶ Department of Radiation Oncology, Royal Marsden NHS Foundation Trust, and The Institute of Cancer Research, London, UK.
¹⁷ Department of Radiation Oncology, Princess Margaret Cancer Center/Mount Sinai Hospital, Toronto, ON, Canada.
¹⁸ Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA.
¹⁹ European Organisation for Research and Treatment of Cancer, Brussels, Belgium.

PMID: 35833413
DOI: 10.1097/SLA.0000000000005492

Abstract

Objective: The aim of the present study was to compare the effect of radiotherapy (RT) on abdominal recurrence-free survival (ARFS) in patients with primary retroperitoneal sarcoma treated in the EORTC-STBSG-62092 (STRASS) phase 3 randomized controlled trial (STRASS cohort) and off-trial (STREXIT cohort) and to pool STRASS and STREXIT data to test the hypothesis that RT improves ARFS in patients with liposarcoma.

Background: The STRASS trial did not show any difference in ARFS between patients treated with preoperative radiotherapy+surgery (RT+S) versus surgery alone (S).

Methods: All consecutive adult patients not enrolled in STRASS and underwent curative-intent surgery for a primary retroperitoneal sarcoma with or without preoperative RT between 2012 and 2017 (STRASS recruiting period) among ten STRASS-recruiting centres formed the STREXIT cohort. The effect of RT in STREXIT was explored with a propensity score (PS)-matching analysis. Primary endpoint was ARFS defined as macroscopically incomplete resection or abdominal recurrence or death of any cause, whichever occurred first.

Results: STRASS included 266 patients, STREXIT included 831 patients (727 after excluding patients who received preoperative chemotherapy, 202 after 1:1 PS-matching). The effect of RT on ARFS in STRASS and 1:1 PS-matched STREXIT cohorts, overall and in patients with liposarcoma, was similar. In the pooled cohort analysis, RT administration was associated with better ARFS in patients with liposarcoma [N=321, hazard ratio (HR), 0.61; 95% confidence interval (CI), 0.42-0.89]. In particular, patients with well-differentiated liposarcoma and G1-2 dedifferentiated liposarcoma (G1-2 DDLPS, n=266) treated with RT+S had better ARFS (HR, 0.63; 95% CI, 0.40-0.97) while patients with G3 DDLPS and leiomyosarcoma had not. At the current follow-up, there was no association between RT and overall survival or distant metastases-free survival.

Conclusions: In this study, preoperative RT was associated with better ARFS in patients with primary well-differentiated liposarcoma and G1-2 DDLPS.

MeSH terms

Adult
Humans
Liposarcoma* / radiotherapy
Liposarcoma* / surgery
Neoplasm Recurrence, Local
Proportional Hazards Models
Retroperitoneal Neoplasms* / radiotherapy
Retroperitoneal Neoplasms* / surgery
Retroperitoneal Space
Sarcoma* / radiotherapy
Sarcoma* / surgery