title: Effect of time to resumption of chemotherapy after definitive surgery on prognosis for non-metastatic osteosarcoma.
abstract: BACKGROUND
  The dose intensity of chemotherapy has been described as affecting the outcome of the treatment of a number of different types of tumors. A delay in the resumption of chemotherapy after definitive surgery for the treatment of osteosarcoma can decrease the overall dose intensity. The goal of this study was to assess the prognostic significance of the time to resumption of chemotherapy after definitive surgery in patients with localized osteosarcoma in an extremity.
  
  
  METHODS
  The relationships of the time between definitive surgery and resumption of chemotherapy with death and adverse events in 703 patients with a localized resectable osteosarcoma in an extremity (556 treated in the Children's Oncology Group [COG] Study [INT 0133] and 147 treated at five tertiary care cancer centers) were assessed with use of Cox proportional hazards models.
  
  
  RESULTS
  The twenty-fifth, fiftieth, and seventy-fifth percentiles of time from definitive surgery to resumption of chemotherapy were twelve, sixteen, and twenty-one days, respectively. Overall survival was poorer for patients who had had a delay of greater than twenty-one days before the resumption of chemotherapy compared with those who had had a shorter delay (hazard ratio = 1.57 [95% confidence interval = 1.04 to 2.36]; p = 0.03). Of seventy-one COG-study patients with postoperative complications, 32% (twenty-three) had a delay of more than twenty-one days before resumption of chemotherapy, but 20% (eighty-nine) of 444 patients with no complications had a similar delay.
  
  
  CONCLUSIONS
  In this retrospective analysis, increased time from the definitive surgery to the resumption of chemotherapy was found to be associated with an increased risk of death of patients with localized osteosarcoma in an extremity. Within the limitations of a retrospective study, the data indicate that it is best to resume chemotherapy within twenty-one days after definitive surgery. Surgeons, oncologists, patients, and those responsible for scheduling need to work together to ensure timely resumption of chemotherapy after surgery.
authors.affiliation: University of South Alabama, 1504 Springhill Avenue, Room 5231, Mobile, AL 36604, USA.
authors.forename: Hamayun
authors.initials: H
authors.lastname: Imran
authors.forename: Felicity
authors.initials: F
authors.lastname: Enders
authors.forename: Mark
authors.initials: M
authors.lastname: Krailo
authors.forename: Franklin
authors.initials: F
authors.lastname: Sim
authors.forename: Scott
authors.initials: S
authors.lastname: Okuno
authors.forename: Douglas
authors.initials: D
authors.lastname: Hawkins
authors.forename: Joseph
authors.initials: J
authors.lastname: Neglia
authors.forename: R Lor
authors.initials: RL
authors.lastname: Randall
authors.forename: Richard
authors.initials: R
authors.lastname: Womer
authors.forename: Leo
authors.initials: L
authors.lastname: Mascarenhas
authors.forename: Carola A S
authors.initials: CA
authors.lastname: Arndt
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D001859:Bone Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000601:surgery; D002675:Child, Preschool; D003131:Combined Modality Therapy; D015987:Effect Modifier, Epidemiologic; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D012516:Osteosarcoma / Q000188:drug therapy / Q000401:mortality* / Q000601:surgery; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult