title: Tumor biology remains the main determinant of prognosis in retroperitoneal sarcomas: a 14-year single-center experience.
abstract: OBJECTIVE
  To review our experience in the management of retroperitoneal sarcomas (RPSs) in a single institution, with a predominantly Asian population, and identify associated prognostic factors for overall survival (OS), disease-free survival (DFS) and local recurrence.
  
  
  METHODS
  All RPSs diagnosed and managed at our center between January 2000 and March 2014 were included. Exclusion criteria included patients whose medical records were untraceable and patients who underwent biopsy but did not undergo resection. The variables studied were age, gender, histological subtype, tumor size, tumor grade, surgical margins, type of presentation of tumor (primary or recurrent) and presence of contiguous organ resection. The primary outcome measured was OS.
  
  
  RESULTS
  Eighty-five patients underwent resection of RPS with curative intent. Eight patients underwent adjuvant chemotherapy and 15 patients underwent radiotherapy. The median DFS was 21 months (range: 0-146) and median OS was 45 months (range: 1-233). On univariate analysis, resection margin (P = 0.04), tumor grade (P = 0.011) and type of presentation of tumor (P = 0.007) were found to significantly affect OS. Patients with tumor adherent to contiguous organs had a greater OS as compared to patients with tumor invasive into the contiguous organs (P = 0.02).
  
  
  CONCLUSIONS
  An aggressive surgical approach in primary and recurrent RPS is associated with good OS. Complete resection, with contiguous organ resection if necessary should be performed to achieve microscopically negative surgical margins to allow for long-term survival. However, tumor biology remains the main determinant for OS.
authors.affiliation: Department of Surgical Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Deanna Wan Jie
authors.initials: DWJ
authors.lastname: Ng
authors.affiliation: Department of Surgical Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Grace Hwei Ching
authors.initials: GHC
authors.lastname: Tan
authors.affiliation: Department of Surgical Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Claramae Shulyn
authors.initials: CS
authors.lastname: Chia
authors.affiliation: Department of Surgical Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Soo Khee
authors.initials: SK
authors.lastname: Chee
authors.affiliation: Department of Medical Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Richard
authors.initials: R
authors.lastname: Quek
authors.affiliation: Department of Medical Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Farid
authors.affiliation: Department of Surgical Oncology, National Cancer Centre Singapore, Singapore.
authors.forename: Melissa Ching Ching
authors.initials: MCC
authors.lastname: Teo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001695:Biology / Q000379:methods*; D017024:Chemotherapy, Adjuvant / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012186:Retroperitoneal Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D012509:Sarcoma / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D016019:Survival Analysis
keywords: retroperitoneal sarcomas