Prognostic factors in chordoma of the sacrum and mobile spine: a study of 39 patients
The prognosis of patients with chordoma of the sacrum and mobile spine has been reported to be dismal and attributable in the majority of cases to intralesional surgery. The purpose of this study was to evaluate the clinical outcome of these patients using modern surgical principles aimed at complete resection and to identify prognostic factors. The clinical and morphologic features, type of surgery, and follow-up of 39 consecutive patients with chordoma were reviewed and analyzed statistically. Thirty sacral and 9 mobile spine chordomas (size range, 3-20 cm; mean, 8 cm) occurring in 22 women and 17 men (median age, 55 years) were analyzed. The preoperative morphologic diagnosis was based on fine-needle aspiration (FNA) biopsy, core needle biopsy, or incisional biopsy. The final surgical margins were wide in 23 patients and marginal or intralesional in 16. The mean follow-up was 8.1 years (range, 0.1-23 years). Seventeen patients (44%) developed local recurrences and 11 patients (28%) developed metastases. The estimated 5-, 10-, 15-, and 20-year survival rates were 84%, 64%, 52%, and 52%, respectively. Local recurrence was associated significantly with an increased risk of metastasis and tumor-related death (P < 0.001). New surgical techniques have improved local control and survival of patients with sacral or spinal chordoma significantly and have decreased progressive neurologic deterioration. Larger tumor size, performance of an invasive morphologic diagnostic procedure outside of the tumor center, inadequate surgical margins, microscopic tumor necrosis, Ki-67 > 5%, and local recurrence were found to be adverse prognostic factors. FNA is the preferred method for establishing the preoperative morphologic diagnosis of chordoma.