Background: The authors hypothesized that the outcomes for young patients who present with primary osteosarcoma of flat bones or secondary osteosarcoma after other primary malignancies are similar because the sites of these tumors rarely makes them amenable to complete surgical resection.
Methods: The authors reviewed their experience with 27 patients with primary osteosarcomas involving flat bones and 18 patients with secondary osteosarcomas of any site, evaluating treatment, metastatic patterns, and outcome.
Results: Eleven of the 27 primary osteosarcomas and 10 of the 18 secondary osteosarcomas were at least partially resectable at the time of initial diagnosis. At last follow-up, 10 of the 27 patients with primary flat bone osteosarcoma were alive, eight of whom were disease free. Three of 18 with the secondary osteosarcoma patients were alive, including one with locally recurrent disease after recent disease resections. Chemotherapy with single or combinations of agents rarely yielded responses for primary flat bone or secondary osteosarcomas.
Conclusions: Outcome for both groups of patients was poor due to metastases and failure of local control. Sixteen of the 27 patients with primary osteosarcoma of flat bones died of their tumor; an additional patient died of doxorubicin-related cardiomyopathy and had microscopic disease in the primary site at autopsy. Thirteen of the 18 patients with secondary osteosarcoma died of their second metastatic cancer, 2 additional patients died of doxorubicin-related cardiomyopathy/coccidioidomycosis, and another of acute renal toxicity.