Page 84 - Predicting survival in patients with spinal bone metastasesL

CHAPTER VI ABSTRACT
Background. Models to aid in the decision making process for the treatment of spinal bone metastases (SBM) have been developed by Tomita, Tokuhashi, Van der Linden, Bauer, Rades and Bollen. The aim of this study was to assess the predictive accuracy of these six models designed to estimate survival of patients suffering from SBM.
Methods. All patients who were treated for SBM between 2000 and 2010 were included in this international multi-center retrospective study (n=1379). Medical records were reviewed for all items needed to employ the models. Survival time was calculated as the difference between start of treatment for SBM and date of death. Survival curves were estimated using the Kaplan-Meier method and accuracy was assessed with the c-statistic. Survival rates of the worst prognostic groups were evaluated at four months.
Results. Median follow-up was 6.7 years (95%CI 5.6-7.7) with a minimum of 2.3 years and a maximum of 12.3 years. The overall median survival was 5.1 months (95%CI 4.6-5.6). The most common primary tumors were breast (n=388, 28%), lung (n=318, 23%) and prostate cancer (n=259, 19%). The Tokuhashi, Bauer, Tomita and Van der Linden models performed similar with a c-statistic of 0.64-0.66 and a 4-month accuracy of 62-65%. The Rades model (c-statistic 0.44) and Bollen model (c-statistic 0.70) had a 4-month accuracy of 69% and 75%, respectively.
Conclusion. The Bollen model performs better than the other models. However, improvements are still warranted to increase the accuracy.
82