Osteosarcoma of the spine: experience of the Cooperative Osteosarcoma Study Group

BACKGROUND: Due to the low incidence rate, the optimal strategy for the treatment of patients with spinal osteosarcoma is unknown. METHODS: Twenty-two patients with osteosarcoma of the spine (15 with tumors of the sacrum and 7 with tumors at other sites) who received chemotherapy according to the Cooperative Osteosarcoma Study Group protocol were analyzed. Six patients presented with metastasis, and 16 patients had no evidence of metastasis at the time of entry into the protocol. Of 12 patients who underwent excision of their tumors, 2 patients underwent wide excision, 3 patients underwent marginal excision, and 7 patients underwent intralesional excision. Eight patients received irradiation: Six patients received conventional radiotherapy only, one patient received neutron beam therapy, and one patient received samarium-153-ethylene diamine tetramethylene phosphonate therapy. Follow-up ranged between 24 months and 105 months (median, 47 months). RESULTS: The median survival was 23 months, and three patients have survived without disease for > 6 years. Patients with primary metastases (P = 0.004), large tumors (P = 0.010), and sacral tumors (P = 0.048) had lower overall survival compared with patients who had no metastasis, small tumors, and nonsacral tumors, respectively. There was a significant difference in overall survival between 5 patients who underwent either wide or marginal surgery and 17 patients who underwent either intralesional surgery or no surgery (P = 0.033). Among 17 patients who underwent no surgery or intralesional surgery, overall survival tended to be better in 7 patients who received irradiation compared with the overall survival in 10 patients who did not receive irradiation (P = 0.059). CONCLUSIONS: Patients with metastases, a large tumors, and sacral tumors had a poor prognosis in the current study with small numbers of patients. Wide or marginal excision of the tumor improved survival. Patients with osteosarcoma of the spine should be treated with a combination of chemotherapy and at least marginal excision for those with surgically accessible tumors. Postoperative radiotherapy may be beneficial.