title: The metastasectomy and timing of pulmonary metastases on the outcome of osteosarcoma patients.
abstract: BACKGROUND
  The author intended to clarify the therapeutic effect and prognostic factors of metastasectomy and timing of pulmonary metastases in osteosarcoma patents.
  
  
  METHODS
  Data was obtained retrospectively on all consecutive osteosarcoma patients from 1985 to 2005 in author's institute. Fifty-two patients with pulmonary nodules were identified, including 24 patients undergoing pulmonary metastasectomy treatment. These patients were categorized into four groups: group 1, patients with lung metastases at the initial presentation; group 2, lung metastases identified during the period of pre-operative chemotherapy; group 3, lung metastases identified during period of the post-operative che motherapy; group 4, lung metastases identified after therapy for the primary osteosarcoma completed.
  
  
  RESULTS
  In our study, the 2-, 3-, and 5-year overall survival rates for 52 patients were 49%, 39% and 20%. The 2-year overall survival rates were 18% for group 1, 32% for group 3, and 70% for group 4 (p < 0.001). The 5-year overall survival rate was 34% for group 4. Patients who underwent metastesectomy showed a better survival outcome as compared with the patients not undergoing metastasectomy (p = 0.003). The 2-year and 5-year overall survival rates of only one lung metastatic nodule were 62% and 50%, and for initially multiple lung metastatic nodules, 45% and 5%, respectively. In addition, the patients presented with lung metastases had a worse prognosis as compared with those without initial lung metastases (p = 0.0001).
  
  
  CONCLUSIONS
  The patients having single metastatic nodule showed a better prognosis than those with multiple lung nodules. Furthermore, those patients who underwent metastasectomy survived longer than those not undergoing metastasectomy. Patients who had late metastases after complete chemotherapy had a better prognosis; whereas those who had metastases identified at the initial presentation predicted a poor prognosis.
authors.affiliation: Departments of Orthopaedics, College of Medicine, National Taiwan University and Hospital, Taipei, Taiwan.
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Huang
authors.forename: Chun-Han
authors.initials: CH
authors.lastname: Hou
authors.forename: Sheng-Mou
authors.initials: SM
authors.lastname: Hou
authors.forename: Rong-Sen
authors.initials: RS
authors.lastname: Yang