title: Extended resection including adjacent organs and Ki-67 labeling index are prognostic factors in patients with retroperitoneal soft tissue sarcomas.
abstract: BACKGROUND
  Because retroperitoneal soft tissue sarcomas (RPS) are extremely rare, there is a significant lack of clinicopathologic information to optimize the treatment strategy. The aim of this study was to evaluate the prognostic factors in RPS, with particular focus on the Ki-67 labeling index (LI).
  
  
  METHODS
  We included the data from a total of 23 patients who received treatment for primary RPS at a single center. The variables analyzed in this study included tumor size, histological type, malignancy grade, necrosis, mitosis, and Ki-67 LI. Kaplan-Meier and Cox proportional regression analyses of overall survival (OS) were performed to identify significant prognostic variables.
  
  
  RESULTS
  Of the 23 patients who underwent surgical resection, 9 (39%) underwent simple resection of the tumor and 14 (61%) extended resection including the adjacent organs. In the univariate analysis, a simple tumor resection and a high Ki-67 LI were associated with shorter OS. The multivariate analysis revealed that simple tumor resection and a high Ki-67 LI were independent negative prognostic factors for OS.
  
  
  CONCLUSIONS
  Our results suggested that combined resection of RPS and its adjacent organs improved OS. Pathologically, a high Ki-67 LI was significantly associated with negative prognosis.
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. tigers.yosuke@gmail.com.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Morizawa
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. makitomiyake@yahoo.co.jp.
authors.forename: Makito
authors.initials: M
authors.lastname: Miyake
authors.affiliation: Department of Pathology, Nara Medical University, Nara, Japan. keijishi@naramed-u.ac.jp.
authors.forename: Keiji
authors.initials: K
authors.lastname: Shimada
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. horimaus@gmail.com.
authors.forename: Shunta
authors.initials: S
authors.lastname: Hori
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. takuro.birds.nest@gmail.com.|Department of Pathology, Nara Medical University, Nara, Japan. takuro.birds.nest@gmail.com.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tatsumi
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. unnkoderu@hotmail.com.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nakai
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. sanai@naramed-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Anai
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. sendo@nmu-gw.naramed-u.ac.jp.
authors.forename: Nobumichi
authors.initials: N
authors.lastname: Tanaka
authors.affiliation: Department of Pathology, Nara Medical University, Nara, Japan. nkonishi@naramed-u.ac.jp.
authors.forename: Noboru
authors.initials: N
authors.lastname: Konishi
authors.affiliation: Department of Urology, Nara Medical University, 840 Shijo-cho, Nara, 634-8522, Japan. kiyokun@naramed-u.ac.jp.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fujimoto
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D012186:Retroperitoneal Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen