Poor Survival for Osteosarcoma of the Pelvis: A Report from the Children's Oncology Group

The pelvis is an infrequent site of osteosarcoma and treatment requires surgery plus systemic chemotherapy. Poor survival has been reported, but has not been confirmed previously by the Children's Oncology Group (COG). In addition, survival of patients with pelvic osteosarcomas has not been compared directly with that of patients with nonpelvic disease treated on the same clinical trials. First, we assessed the event-free (EFS) and overall survival (OS) of patients with pelvic osteosarcoma treated on COG clinical trials. We then asked whether patient survival compared with that of patients treated on the same clinical trials with nonpelvic disease. Finally, we asked whether patients with metastatic disease at initial diagnosis had worse survival. We retrospectively reviewed data from 1054 patients with osteosarcoma treated in four studies between 1993 and 2005. Twenty-six of the 1054 patients (2.5%) had a primary tumor of the pelvis. At diagnosis, nine patients had metastatic disease. The minimum followup was 2 months (mean, 34 months; range, 2-102 months). Two of the nine patients with metastatic disease at diagnosis and five of the 17 with localized disease were alive at last contact. Estimates of the 5-year EFS for localized versus metastatic disease of the pelvis were 22% versus 23%. OS for patients with localized versus metastatic disease was 47% versus 22%. Patients with osteosarcoma in all other locations had a 5-year EFS of 57% and OS of 69%. Our analysis confirms poor survival for patients with pelvic osteosarcoma. Survival with metastatic disease in the absence of a pelvic primary tumor is similar to that for localized or metastatic pelvic osteosarcoma. Improved surgical or medical therapy is needed, and patients with pelvic osteosarcoma may warrant alternate or experimental therapy. Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.