Evaluation of Prognostic Factors and Proposed Changes to the Modified Tokuhashi Score in Patients With Spinal Metastases From Breast Cancer

Study Design. A retrospective study of all patients with histologically confirmed breast cancer spinal metastases presenting to a single institution between May 2001 and April 2012. Objectives. The aim of this study was to investigate whether the 2014mT is more accurate than the 2005mT. Summary of Background Data. The commonly used 2005 modified Tokuhashi score (2005mT) has become more inaccurate as oncologists move toward treating tumors according to their molecular and genomic profile, rather than their tissue-oforigin. In attempts to improve the accuracy of the 2005mT, a revised score (2014mT) was published, suggesting that hormone receptor negative and triple-negative breast cancer patients be given a modified Tokuhashi histological score of 3 rather than 5. Methods. Demographic characteristics, tumor receptor status, clinical findings in relation to the primary tumor and its metastases, and actual survival time were collated. The 2005mT was compared with the 2014mT. Univariate and multivariate Cox regression analyses were used to evaluate the influence of each parameter on survival, and receiver operating characteristic curves were used to determine predictive values of each score version. Results. Of the 185 patients included, 32 underwent operative treatment, while 153 were managed nonoperatively for their spinal metastases. The overall cohort had a median survival time of 24 months following the diagnosis of spinal metastases, with a 6-month survival rate of 90%. Hormone, HER2 and triplenegative receptor statuses were significant predictors of poorer survival upon multivariate analysis (P = 0.004, P = 0.007, P < 0.001, and P < 0.001, respectively). Age, the original Tokuhashi score components, previous breast surgery for cancer, previous radiotherapy to the breast, previous radiotherapy to the spine, previous chemotherapy, and previous immunotherapy were not significant. At 6 months, the 2005mT AUROC was 0.62, while that of the 2014mT was 0.64 (P = 0.5394). Conclusion. Tumor histological subtype is crucial when prognosticating the survival of patients with breast cancer spinal metastases. Although the 2014mT was marginally more accurate than the 2005mT, its predictive ability remains poor.