title: Postrelapse Prognostic Factors in Nonmetastatic Osteosarcoma: A Single-institution Experience.
abstract: OBJECTIVE
  The purpose of this study was to analyze the prognostic factors that influence postrelapse survival (PRS) in children and adolescents with initial localized high-grade osteosarcoma.
  
  
  METHODS
  This is a retrospective evaluation of patients aged 21 years and below with nonmetastatic high-grade osteosarcoma treated at our institution from 1985 to 2011 who developed recurrent disease after achievement of an initial complete response (CR). PRS and postrelapse event-free survival (PREFS) analyses were performed using the Kaplan-Meier method and log-rank test. Multivariate Cox regression analysis was used to determine which variables were independently prognostic.
  
  
  RESULTS
  Thirty-one patients were included. Median age at primary diagnosis was 13.7 years (range, 1.9 to 21.0 y). Median time to first relapse was 16 months (range, 3 to 36 mo). Fourteen patients achieved a second CR (CR2) after surgery±chemotherapy treatment. The 5-year PRS and PREFS were both 26% (95% confidence interval, 14%-49%), with a median follow-up of 99 months (range, 27 to 271 mo). Multivariate analysis showed that achievement of CR2 (P<0.001) and histologic response to first-line treatment (P=0.02) were significantly associated with PRS, whereas time to first relapse did not retain univariate significance.
  
  
  CONCLUSIONS
  Achievement of CR2 and histologic response to preoperative first-line treatment are independent survival prognostic factors in osteosarcoma recurrence.
authors.affiliation: *Pediatric Oncology Unit †Pediatric Orthopedics Unit ‡Medical Oncology Department §Pediatric Radiology Unit ∥Pediatric Surgery Department, Hospital La Fe ¶Cancer Clinical and Translational Research Group, Health Research Institute La Fe, Valencia, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Berlanga
authors.forename: Adela
authors.initials: A
authors.lastname: Cañete
authors.forename: Marta
authors.initials: M
authors.lastname: Salom
authors.forename: Joaquin
authors.initials: J
authors.lastname: Montalar
authors.forename: Maria
authors.initials: M
authors.lastname: Guasp
authors.forename: Alfredo
authors.initials: A
authors.lastname: Marco
authors.forename: Victoria
authors.initials: V
authors.lastname: Castel
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D017024:Chemotherapy, Adjuvant / Q000379:methods; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology*; D012516:Osteosarcoma / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D055815:Young Adult