Analysis of Four Scoring Systems for the Prognosis of Patients with Metastasis of the Vertebral Column

Objective Metastatic spinal diseases are common health problems and there is no consensus on the appropriate treatment of metastases in several conditions. Using clinical measures (e.g., survival time and functional status), prognosis prediction systems advise on the appropriate interventions. The aim of this article is to assess and compare 4 widely used scoring systems (revised Tokuhashi, Tomita, van der Linden, and modified Bauer scores) on a single-center cohort. Methods A retrospective study was designed of 329 patients who were subjected to surgery because of metastatic spinal diseases. Subpopulations according to the classifications of the 4 scoring systems were identified. The overall survival was calculated with the Kaplan-Meier formula. The difference between the survival curves of subpopulations was analyzed with log-rank tests. The consistency rates for the 4 scoring systems are calculated as well. Results The follow-up period was 8 years. The median survival time was 222 days. The overall survival of prognostic categories in 3 scoring systems was significantly different from each other, but we found no differences between the categories of the van der Linden system. In this cohort, the revised Tokuhashi system gave the best approximation for survival, with a mean predictive capability 60.5%. Conclusions The evaluation of 4 standard scoring systems showed that 3 were self-consistent, although none of systems was able to predict the survival in our cohort. Based on the predictive capability, the revised Tokuhashi system may provide the best predictions with careful examination of individual cases.