title: Clinical outcome after bone metastasis (BM) surgery in patients with differentiated thyroid carcinoma (DTC): a retrospective study of 40 cases.
abstract: OBJECTIVE
  The purpose of this study is to identify factors that affect survival of patients with differentiated thyroid carcinoma with bone metastases and to optimize surgical treatment modality for bone metastatic lesion by comparing duration of patient survival and local control.
  
  
  METHODS
  We examined 52 bone metastatic lesions from 40 patients with differentiated thyroid carcinoma who were treated surgically between 1994 and 2008 at Keio University Hospital. Median follow-up time was 46 months (range: 4-233 months). Patients' disease-specific survival, local control duration and factors that potentially affected disease-specific survival after bone metastasis surgery were statistically analyzed.
  
  
  RESULTS
  The 2-, 5- and 10-year disease-specific survival rates were 77.2, 64.3 and 45.7%, respectively. Factors that were significantly associated with poor survival rates in multivariate analyses included age at bone metastasis surgery ≥65 years (P = 0.0068), time from diagnosis of primary cancer to bone metastasis surgery ≥5 years (P = 0.0018) and presence of visceral metastases (P = 0.0092). The 2-, 5- and 10-year local control rates in our series were 91.4, 72.7 and 63.6%, respectively. The 5-year local control rates for radical and palliative surgery were 84.4 and 55.3%, respectively, and differed significantly (P = 0.019).
  
  
  CONCLUSIONS
  Because disease-specific survival of patients with differentiated thyroid carcinoma is fairly good, inadequate treatment of bone metastatic lesions can result in severe disabilities. Therefore, radical surgery for bone metastatic lesions should be considered, especially for those with favorable prognostic factors.
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan robert@a2.keio.jp.
authors.forename: Robert
authors.initials: R
authors.lastname: Nakayama
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Horiuchi
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Michiro
authors.initials: M
authors.lastname: Susa
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Itsuo
authors.initials: I
authors.lastname: Watanabe
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuji
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Morio
authors.initials: M
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Morioka
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology*; D016896:Treatment Outcome
keywords: bone metastasis; differentiated thyroid carcinoma; prognosis; surgery; survival