Prognostic factors and outcome of pelvic, sacral, and spinal chondrosarcomas: a center-based study of 69 cases.

BACKGROUND:
The surgical treatment of chondrosarcoma of the pelvis, sacrum, and spine is complex and technically demanding. As such, adequate surgical margins have been difficult to achieve, resulting in poor local control and survival. The objective of this study was to assess the outcome of patients with chondrosarcomas in these sites who were treated at a tumor center by using modern, aggressive surgical techniques and to identify prognostic factors.

METHODS:
Sixty-nine consecutive patients with chondrosarcoma of the pelvis (46 cases), sacrum (11 cases), and mobile spine (12 cases) who were treated at Sahlgrenska University Hospital from 1967 to 1999 were included in this study. Demographic information and follow-up data were obtained and statistically analyzed.

RESULTS:
There were 53 men and 16 women with a mean age of 45 years and a mean tumor size of 12 cm. There were 61 conventional chondrosarcomas, Grades 1-3 (with 13 arising in a preexisting osteochondroma) and 8 Grade 4 chondrosarcomas (7 dedifferentiated and one mesenchymal). The overall local recurrence rate was 27%, and the estimated overall 5- and 10-year survival rates were 72% and 67%, respectively. In contrast, the observed local recurrence rate was 3% (1 patient) in 31 patients whose conventional chondrosarcomas were resected with adequate surgical margins; 90% of these patients survived and most of them (26 of 31 or 84%) were continuously disease free. Significant factors associated with a worse prognosis with respect to local control and/or survival were high histologic tumor grade, increasing patient age, primary surgery outside of a tumor center, incisional biopsy versus a noninvasive diagnostic procedure, and inadequate surgical margins.

CONCLUSIONS:
Center-based diagnosis and treatment using modern aggressive surgical techniques significantly improve the prognosis of patients with chondrosarcoma of the pelvis, sacrum, and spine.