Osteosarcoma of the pelvis in children and young adults: the St. Jude Children's Research Hospital experience.

BACKGROUND: Pelvic osteosarcomas are difficult to resect. The authors reviewed their institution's experience with patients who had such tumors to characterize the patients' clinical findings and to assess the impact of surgical resection on outcome.

METHODS: A review was conducted of the records from patients with pelvic osteosarcoma who were treated at the authors' institution between January, 1970 and March, 2004.

RESULTS: Among 442 patients with osteosarcoma, 19 patients (4%) had high-grade tumors arising in the pelvic bones, including the ilium in 15 patients, the pubis in 2 patients, and the sacrum in 2 patients. The median patient age at diagnosis was 16.8 years. Four tumors were secondary to radiation therapy. Five patients had metastases in the lung (n = 4 patients) or bone (n = 1 patient) at diagnosis. Ten tumors were chondroblastic. The median greatest tumor dimension for the 13 tumors with known size was 10 cm. Ten patients had unresectable pelvic tumors, and 9 patients underwent hemipelvectomy (2 internal and 7 external); complete resection with negative margins was achieved in 5 patients. Four patients survived, including one patient who survived with disease. Of the three patients who survived disease-free, one patient underwent complete resection, one patient underwent incomplete resection (nonviable tumor at the soft tissue margin) with a good response to chemotherapy, and one patient with a sacral tumor underwent radiotherapy only for local control. Of the 9 patients who underwent resection, 7 experienced disease recurrence (n = 5 patients) or progression (n = 2 patients) at distant sites and died. All patients with metastatic disease at diagnosis died.

CONCLUSIONS: Pelvic osteosarcomas often were large and unresectable. A high propensity for metastasis contributed to the poor outcome of patients with pelvic osteosarcoma. New therapeutic approaches are needed.