Updating Prognostic Assessment for Spinal Metastases With a Combined Model of the Spinal Instability Neoplastic Score and the New Katagiri Score

Study DesignProspective Cohort Study.ObjectivesThe rapidly evolving landscape of cancer care alters the prognostic accuracy of established scoring systems for metastatic spinal tumors. This study aimed to provide a contemporary assessment of patient survival and examine the independent and complementary roles of the new Katagiri score (a systemic prognostic tool) and the Spinal Instability Neoplastic Score (SINS, a mechanical instability tool) in predicting 6-month mortality, laying a foundation for future combined prognostic model development.MethodsWe prospectively analyzed 151 patients with metastatic spinal tumors treated between 2021 and 2023. Demographic, clinical, and treatment data, including the new Katagiri score and SINS, were collected. The primary endpoint was 6-month mortality, which was evaluated using trend tests, correlation, and multivariate logistic regression.ResultsThe 6-month mortality rate was 25.17%. Higher scores in both the new Katagiri score and the SINS were significantly associated with an increased risk of 6-month mortality. Notably, no significant correlation was observed between the total Katagiri score and the total SINS. Stratified analyses showed that prognostic factors for early mortality differed across new Katagiri score risk groups, with varying influences from specific Katagiri score items, SINS components, and spinal metastasis levels. SINS-related factors had a significant impact in the high-risk group.ConclusionsThe new Katagiri score and SINS independently predicted 6-month mortality in our cohort. Our findings suggest that considering both complementary measures may further refine prognostic assessment, providing a rationale for future prospective model development and validation.