Surgery for solitary metastases of the spine: Rationale and results of treatment

Study Design. A spine tumor database of patients with solitary sites of spine involvement from solid tumors was retrospectively reviewed. Objectives. To analyze the long-term survival, neurologic outcome, and results of surgery in a well-defined subset of patients who had spinal metastases with epidural extension to define future treatment strategies. Summary of Background Data. Currently accepted indications for surgical treatment of spinal metastases include histologic diagnosis, neurologic palliation in those who have failed prior irradiation, and spinal stabilization. In all others, external irradiation is considered the main-stay of therapy. Several studies have shown that prior irradiation increases the frequency of complications from surgery and affects functional outcome. Methods. A retrospective review of 80 consecutive patients with solitary sites of spine involvement from solid tumors with varying degrees of epidural extension was performed. Complete clinical and radiologic follow-up assessment was available for all the patients. Clinical parameters, neurologic grade, preoperative pain, radiologic evaluation, and outcome measures were analyzed. Survival analysis was performed using the Kaplan-Meier product limit method, and differences between subgroups were analyzed using X². Prognostic factors for long-term survival also were evaluated. Results. The overall median survival after surgery was 30 months, with 18% surviving 5 years or more. Survival varied by tumor type, with the best prognosis noted in patients with breast or kidney cancer. The surgical morbidity was significantly higher in those receiving prior irratiation (P < 0.03), and the local recurrence rate also increased in patients who had received prior irradiation. Conclusions. Patients with solitary sites of spine involvement from solid tumors represent a biologically favorable subgroup with potential for long-term survival. In this group, complete surgical excision before irradiation should be considered to increase the prospects of long-term palliation and possible cure.