VALIDATION OF THE TOKUHASHI SCORE AND TOMITA SCORE IN PREDICTING SURVIVAL IN PATIENTS WITH SPINAL METASTASES: A RETROSPECTIVE COHORT STUDY IN AN LMIC POPULATION

Abstract

Background: Proper preoperative prognostication is critical in making surgical decisions and resource allocation in patients with spinal metastases. The Tokuhashi and Tomita scores have been revised, but their effectiveness in low- and middle-income country (LMIC) settings with delayed presentation and limited adjuvant therapies remains poorly assessed. Methods: This retrospective cohort study included adult patients (aged 18 years and older) who underwent surgery for spinal metastasis at a tertiary neurosurgical unit between January 1, 2020, and December 31, 2025. Standardized parameters were used to calculate preoperative revised Tokuhashi and Tomita scores. The main outcome was overall survival (OS) after surgery. Harrell measured discrimination using the C-index and 6- and 12-month time-dependent area under the receiver operating characteristic curve (AUC) of survival. The DeLong test was used to assess comparative discrimination. Decision curve analysis (DCA) measured net clinical benefit at threshold probabilities. Independent predictors were determined using multivariable Cox regression. Results: Among 265 surgical patients, 228 were eligible (mean age 56.8 ± 13.1 years; 61% male). Median OS was 8.4 months (IQR 3.2–15.6); 12-month survival was 42.5%. The revised Tokuhashi score was better discriminatory (C-index 0.73, 95% CI 0.68 0.78) than the Tomita score (C-index 0.68, 95% CI 0.62 0.73). Tokuhashi was statistically better on DeLong testing (12-month survival) (AUC 0.71 vs 0.67; 0.04 difference, p=0.041). DCA showed a higher net benefit of the Tokuhashi score with a 20-50% threshold probability of 12-month mortality. A subgroup with high risk (Tokuhashi ≤8 and untreatable visceral metastases, n=62) had a median OS of 3.9 months (6-month survival 19.4%). The independent predictors were Tokuhashi score (adjusted HR 0.82 per point increase, 95% CI 0.760.88, p<0.001), rapid-growing primary tumours, visceral metastases, and postoperative complications. Conclusion: In this LMIC cohort, the revised Tokuhashi score shows slightly better discrimination and clinical utility than the Tomita score. Preoperative use is supported by routine use to help select surgical versus palliative care, especially in resource-constrained settings, based on evidence.