title: Leiomyosarcoma: investigation of prognostic factors for risk-stratification model.
abstract: BACKGROUND
  We performed this study to define distinctive clinical features of leiomyosarcoma by assessing prognostic factors.
  
  
  METHODS
  Between 1988 and 2011, 129 leiomyosarcoma patients who underwent surgical resection with curative intent were retrospectively reviewed.
  
  
  RESULTS
  Of the 129 leiomyosarcoma patients, the distribution of anatomic locations was: extremity (n = 25), pelvis (n = 40), thoracic cavity (n = 11), intra-abdomen (n = 19), retroperitoneum (n = 23), and head/neck (n = 11). We classified the anatomic locations into two categories as abdominal (intra-abdomen and retroperitoneum, n = 42) and extra-abdominal (extremity, pelvis, thoracic cavity, and head/neck, n = 87). Prognosis was worse for the abdominal group than for the extra-abdominal group (median DFS 2.9 9.0 years, P = 0.04). Similarly, overall survival (OS) was also significantly worse for abdominal group (P = 0.027). Independent prognostic factors for survival were primary site (P = 0.041, hazard ratio (HR) 1.7; 95 % CI 1.2-2.8), tumor size (P = 0.038, HR 1.9; 95 % CI 1.13-3.38), margin status (P = 0.019, HR 2.1; 95 % CI 1.13-3.88), and histology grade (P = 0.01, HR 3.59; 95 % CI 1.64-7.87). We identified four different risk groups with different survival outcome: group 1 (n = 8), no adverse factors; groups 2 (n = 37) and 3 (n = 61) with one and two adverse factors, and group 4 (n = 23) with 3 or 4 adverse factors.
  
  
  CONCLUSIONS
  Primary site, tumor size, resection margin, and histology subtype were independently associated with survival outcome. A prognostic model for leiomyosarcoma patients revealed four distinct groups of patients with good prognostic discrimination.
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-Gu, Seoul, 120-752, Korea.|Yonsei University Graduate School of Medicine, Seoul, Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-Gu, Seoul, 120-752, Korea.
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Soo Hee
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-Gu, Seoul, 120-752, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Rha
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-Gu, Seoul, 120-752, Korea.
authors.forename: Joong Bae
authors.initials: JB
authors.lastname: Ahn
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Woo Ick
authors.initials: WI
authors.lastname: Yang
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin-Suck
authors.initials: JS
authors.lastname: Suh
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-Gu, Seoul, 120-752, Korea.
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Roh
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyung Sik
authors.initials: KS
authors.lastname: Kim
authors.affiliation: Department of Urology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Deuk
authors.initials: YD
authors.lastname: Choi
authors.affiliation: Department of Orthopaedic Surgery, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-Gu, Seoul, 120-752, Korea. QSHIN@yuhs.ac.
authors.forename: Kyoo-Ho
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-Gu, Seoul, 120-752, Korea. hyosong77@yuhs.ac.
authors.forename: Hyo Song
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005121:Extremities; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D007890:Leiomyosarcoma / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D018365:Neoplasm, Residual; D010386:Pelvic Neoplasms / Q000473:pathology* / Q000601:surgery*; D011379:Prognosis; D016016:Proportional Hazards Models; D012186:Retroperitoneal Neoplasms / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D013899:Thoracic Neoplasms / Q000473:pathology* / Q000601:surgery*; D047368:Tumor Burden; D055815:Young Adult
keywords: Leiomyosarcoma; Prognostic factors; Risk stratification model