Factors associated with improved survival following surgical treatment for metastatic prostate cancer in the spine: retrospective analysis of 29 patients in a single center

BACKGROUND Prostate cancer (PCa) is very common and frequently metastasizes to the spine. However, PCa spinal metastases were rarely reported in the literature. In this study, the outcome of therapies and prognostic factors affecting surgical outcomes for patients with PCa spinal metastases are discussed to select the best candidates for aggressive surgical resection. METHODS All patients affected by the spinal metastatic PCa surgically treated at our spine tumor center were reviewed. Overall survival was analyzed from the time of spinal surgery. A univariate survival analysis and a multivariate Cox proportional hazard analysis to identify independent prognostic factors were carried out. The survival rate was estimated by the Kaplan-Meier method, and differences were analyzed by the log-rank test. Factors with P values of 0.1 or less were subjected to multivariate analysis for survival rate by multivariate Cox proportional hazard analysis. RESULTS A total of 31 consecutive patients were identified. Of these, 29 underwent surgical resection. The median survival time of all patients after their spinal surgery was 44.0 months. Visceral metastases, revised Tokuhashi scores (0-8/9-11/12-15), Tomita scores (7-10/2-6), hormone status, and bisphosphonate treatment were suggested as the potential prognostic factors through univariate analysis. As they were submitted to the multivariate Cox regression model, visceral metastases and Tomita score were found as independent prognostic factors. CONCLUSIONS Patients without visceral metastases and a Tomita score no more than 6 are favorable prognostic factors for PCa metastases in the mobile spine.