title: Osteosarcomas after the age of 50: a clinicopathologic study of 64 cases--an experience in northern Japan.
abstract: BACKGROUND
  The clinicopathologic profile and prognostic factors of osteosarcomas after the age of 50 years have been obscure.
  
  
  METHODS
  Clinicopathologic features were analyzed in 645 patients with osteosarcoma who were registered at the Tohoku Musculoskeletal Tumor Society and National Cancer Center in Tokyo between 1972 and 2002.
  
  
  RESULTS
  Sixty-four patients (9.9%; 34 men and 30 women) were more than 50 years old. The most common location was the distal femur (n = 13), followed by the pelvis (n = 10), proximal femur (n = 9), and proximal fibula (n = 6). Seven (11%) patients had lung metastasis at initial presentation. On radiographs, an osteolytic appearance without periosteal reactions was a common and characteristic feature. Forty-eight tumors (75%) were classified as conventional osteosarcomas. Fourteen cases (22%) were secondary; postradiation osteosarcoma was most common in these patients, but there was no Paget's sarcoma. At the initial presentation, misdiagnoses without biopsy were made in 15 (23%) of the 64 cases. Preoperative chemotherapy was given to 22 patients, but the effect was poor in 18 cases (82%). Fifty-four patients underwent surgery, whereas the other 10 patients were treated without surgery because of systemic or inoperable local conditions. The overall survival rate at 5 years was 55.5%. Multivariate analysis showed initial pulmonary metastasis, axial tumor location, and larger tumors as significant prognostic factors.
  
  
  CONCLUSIONS
  In northern Japan, most patients with osteosarcoma after the age of 50 had primary osteosarcoma. Careful radiological examination and biopsy are mandatory for correct diagnosis. Current systemic chemotherapy is not effective for this age group. Alternative treatment strategies should be considered.
authors.affiliation: Department of Orthopedic Surgery, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543 Japan. cshokada@med.akita-u.ac.jp
authors.forename: Kyoji
authors.initials: K
authors.lastname: Okada
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Jun
authors.initials: J
authors.lastname: Nishida
authors.forename: Akira
authors.initials: A
authors.lastname: Ogose
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tajino
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Osanai
authors.forename: Michiro
authors.initials: M
authors.lastname: Yanagisawa
authors.forename: Masahito
authors.initials: M
authors.lastname: Hatori
mesh_terms: D017668:Age of Onset; D000368:Aged; D001859:Bone Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009362:Neoplasm Metastasis; D012516:Osteosarcoma / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies