REtroperitoneal SArcoma Registry: an International Prospective Initiative

Surgery is currently the only potentially curative treatment modality for localized retroperitoneal sarcoma (RPS). Available studies regarding oncologic outcomes are mainly retrospective in nature, and RPS are recognized as a rare disease. Therefore, prospective analysis of high quality data is a top priority. Primary Objectives of this study are: * to prospectively collect standardized clinical data and radiological and pathological material from primary RPS patients treated with surgery at reference centers. * patient outcome will be evaluated in terms of overall survival (OS), disease-free survival (DFS), crude cumulative incidence (CCI) of local recurrence (LR) and distant metastasis (DM). Secondary Objectives: * to estimate the efficacy and safety of surgical treatment, including extended surgical approach to primary RPS; * to prospectively evaluate the impact of multimodality therapy, including radiation therapy and chemotherapy; * to identify clinical, radiological and pathological characteristics that may influence the oncological outcome or may be used as predictors of LR/DM/OS. These may be important biomarkers of disease; * to utilize collected pathological material for research collaborations.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* primary RPS operated on in the participating center;
* age\>18 years at the time of the first treatment (pediatric patients can not be included)
* histological confirmed diagnosis according to the WHO criteria done on biopsy or surgical specimen by dedicated sarcoma pathologist;
* radiological examinations performed (contrast enhanced abdominal CT scan and/or MRI) prior to surgical resection;
* signed informed consent form;
* adequate compliance of the patients to the plan of follow-up

Exclusion Criteria:

* age\<18 years;
* recurrent tumor;
* benign retroperitoneal tumors;
* serious psychiatric disease that precludes informed consent or limits compliance;
* impossibility to ensure adequate follow-up

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• BACKGROUNDTrans-Atlantic RPS Working Group. Management of primary retroperitoneal sarcoma (RPS) in the adult: a consensus approach from the Trans-Atlantic RPS Working Group. Ann Surg Oncol. 2015 Jan;22(1):256-63. doi: 10.1245/s10434-014-3965-2. Epub 2014 Oct 15. PMID 25316486
• BACKGROUNDMacNeill AJ, Gronchi A, Miceli R, Bonvalot S, Swallow CJ, Hohenberger P, Van Coevorden F, Rutkowski P, Callegaro D, Hayes AJ, Honore C, Fairweather M, Cannell A, Jakob J, Haas RL, Szacht M, Fiore M, Casali PG, Pollock RE, Barretta F, Raut CP, Strauss DC. Postoperative Morbidity After Radical Resection of Primary Retroperitoneal Sarcoma: A Report From the Transatlantic RPS Working Group. Ann Surg. 2018 May;267(5):959-964. doi: 10.1097/SLA.0000000000002250. PMID 28394870
• DERIVEDBenuzzi L, Iadecola S, Fiore M, Baia M, Colombo C, Radaelli S, Di Blasi E, Morosi C, Sanfilippo R, Callegaro D, Gronchi A. Pancreaticoduodenectomy and IVC resection in retroperitoneal sarcoma: Expanding the limits of feasible surgery. Eur J Surg Oncol. 2026 Jan;52(1):110547. doi: 10.1016/j.ejso.2025.110547. Epub 2025 Oct 26. PMID 41176815
• DERIVEDXiao M, Li X, Bu F, Ma S, Yang X, Chen J, Zhao Y, Cananzi F, Luo C, Min L. Molecular feature-based classification of retroperitoneal liposarcoma: a prospective cohort study. Elife. 2025 May 23;14:RP100887. doi: 10.7554/eLife.100887. PMID 40407808
• DERIVEDZhao Y, Qin D, Li X, Wang T, Zhang T, Rao X, Min L, Wan Z, Luo C, Xiao M. Identification of NINJ1 as a novel prognostic predictor for retroperitoneal liposarcoma. Discov Oncol. 2024 May 11;15(1):155. doi: 10.1007/s12672-024-01016-x.