Variability in Patterns of Recurrence after Resection of Primary Retroperitoneal Sarcoma (RPS) A Report on 1007 Patients from the Multi-institutional Collaborative RPS Working Group
Alessandro Gronchi, MD1, Dirk C. Strauss, MD2, Rosalba Miceli, MD, PhD3, Sylvie Bonvalot, MD, PhD4, Carol J. Swallow, MD5, Peter Hohenberger, MD6, Frits Van Coevorden, MD7, Piotr Rutkowski, MD8, Dario Callegaro, MD1, Andrew J. Hayes, MD, PhD2, Charles Honore, MD4, Mark Fairweather, MD9, Amanda Cannell, MD5, Jens Jakob, MD6, Rick L. Haas, MD10, Milena Szacht, MD8, Marco Fiore, MD1, Paolo G. Casali, MD11, Raphael E. Pollock, MD, PhD12, Chandrajit P. Raut, MD9
1Department of Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; 2Department of Surgery, Royal Marsden Hospital NHS Foundation Trust, London, United Kingdom; 3Department of Biostatistics, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; 4Department of Surgery, Institute Gustave Roussy, Villejuif, France; 5Department of Surgical Oncology, Mount Sinai Hospital and Princess Margaret Cancer Centre, and Department of Surgery, University of Toronto, Toronto, Ontario, Canada; 6Division of Surgical Oncology & Thoracic Surgery, Mannheim University Hospital, Mannheim, Germany; 7Department of Surgical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands; 8Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland; 9Department of Surgery, Division of Surgical Oncology, Brigham and Women's Hospital and Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA; 10Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands; 11Department of Cancer Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; and 12Department of Surgery, Division of Surgical Oncology, Ohio State University Medical Center, Columbus, OH
Purpose: Retroperitoneal sarcomas (RPS) are rare tumours composed of several well-defined histologic subtypes. The aim of this study was to analyze patterns of recurrence and treatment variations in a large population of patients, treated at reference centres.
Methods: All consecutive patients with primary RPS treated at 6 European and 2 North American institutions between January 2002 and December 2011 were included. Five, 8 and 10-year overall survival (OS) and crude cumulative incidence (CCI) of local recurrence (LR) and distant metastases (DM) were calculated. Multivariate analyses for OS, CCI of LR and DM were performed.
Results: In all, 1007 patients were included. Median follow-up was 58 months (1st and 3rd quartile range 36-90). The 5, 8 and 10-yr OS were 67% [95% confidence interval (CI) 63, 70], 56% (52, 61) and 46% (40, 53). The 5, 8 and 10-yr CCI of LR and DM were 25.9 (23.1,29.1), 31.3 (27.8, 35.1), 35% (30.5,40.1) and 21% (18.4,23.8%), 21.6 (19.0,24.6), 21.6 (19.0,24.6) respectively. Tumour size, histologic subtype, malignancy grade, multifocality, and completeness of resection were significant predictors of outcome. Patterns of recurrence varied depending on histologic subtype. Different treatment policies at participating institutions influenced LR of well-differentiated Liposarcoma without impacting OS, while discrepancies in adjuvant systemic therapies did not impact LR, DM, or OS of Leiomyosarcoma.
Conclusions: Reference centers are critical to outcomes of RPS patients, as the management strategy requires specific expertise. Histologic subtype predicts patterns of recurrence and should inform management decision. A prospective international registry is under preparation, to further define our understanding of this disease.
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