Survival analysis of 254 patients after manifestation of spinal metastases: evaluation of seven preoperative scoring systems

Abstract

Study design: Retrospective study.

Objective: This study analyzed the predictive value of the scoring systems of Bauer, Bauer modified, Tokuhashi, Tokuhashi revised, Tomita, van der Linden, and Sioutos as well as the parameters included in these systems.

Summary of background data: Metastases of the spinal column are a common manifestation of advanced cancer. Severe pain, pathologic fracture, and neurologic deficit due to spinal metastases need adequate treatment. Besides oncologic aspects and quality of life, treatment decisions should also include the survival prognosis.

Methods: Two hundred fifty-four patients with confirmed spinal metastases were investigated retrospectively (treatment 1998-2006; 62 underwent surgery and 192 had conservative treatment only). Factors related to survival, such as primary tumor, general condition (Karnofsky Performance Status Scale), neurologic deficit, number of spinal and extraspinal bone metastases, visceral metastases, and pathologic fracture, were analyzed. The survival period was calculated from date of diagnosis of the spinal metastases to date of death or last follow-up (minimum follow-up: 12 months). For statistical analysis, univariate and stepwise multivariate Cox regression analyses were performed.

Results: Median overall survival for all patients was 10.6 months. The following factors showed significant influence on survival in multivariate analysis: primary tumor (P < 0.0001), status of visceral metastases (P < 0.0001), and systemic therapy (P < 0.0001). Using the recommended group assignment for each system, only Bauer and Bauer modified showed significant results for the distinction between good, moderate, and poor prognosis. The other systems failed to distinguish significantly between good and moderate prognosis. The hazard ratio of the absolute score of all analyzed systems was, however, statistically significant, with a better score leading to lower risk of death.

Conclusion: According to this analysis, the Bauer and the Bauer modified scores are the most reliable systems for predicting survival. Since the Bauer modified score furthermore consists of only four positive prognostic factors, we emphasize its impact and simplicity.