Research on the predicting power of the revised Tokuhashi system: how much time can surgery give to patients with short life expectancy?

Predicting survival of patients with spinal metastatic disease using PathFx 3.0 - A validation study of 668 patients in Sweden

Introduction

PathFx is a computer-based prediction model for estimating survival of patients with bone metastasis. The model has been validated in several studies, but this is the first validation using exclusively patients with spinal metastases.

Research question

Is PathFx 3.0 a tool useful for predicting survival for patients with spinal metastatic disease?

Material and methods

668 patients (67% male, median age 67 years) presenting with spinal metastases at two university hospitals in Sweden 1991-2014 were included. Of those, the majority (82%, n ​= ​551) underwent surgery. Data on all patients was analyzed with PathFx version 3.0, generating a probability of survival at 1, 3, 6, 12, 18 and 24 months. The predictions were compared to real survival data and the precision in estimation was evaluated with Receiver-Operating Characteristic curve (ROC) analysis where the Area Under Curve (AUC) was calculated. Brier score and decision curve analyses were also assessed.

Results

The AUC for 1-, 3-, 6- and 12 months survival predictions were 0.64 (95% CI 0.5-0.71), 0.71 (95% CI 0.67-0.75), 0.70 (95% CI 0.66-0.77) and 0.74 (95% CI 0.70-0.78). For 18- and 24 months survival the AUC were 0.74 (95% CI 0.69-0.78) and 0.76 (95% CI 0.72-0.81). The Brier scores were all 0.23 or lower depending on the estimated survival time.

Discussion and conclusion

PathFx 3.0 is a reasonably reliable tool for predicting survival in patients with spinal metastatic disease. As the PathFx computer model can be updated to reflect advancements in oncology, we suggest this type of model, rather than rigid point-based scoring systems, to be used for estimating survival in patients with metastatic spinal disease in the future.

Prognosis after Palliative Surgery for Patients with Spinal Metastasis: Comparison of Predicted and Actual Survival

Simple Summary

Increased options for cancer treatment have made the prediction of prognosis an important factor in therapeutic decision making. The aim of this study was to assess the clinical significance of prognosis–scoring systems and to identify predictors for 6–month mortality after palliative surgery. The median actual survival period was longer than the predicted life expectancy based on the revised Tokuhashi score and new Katagiri score. However, 21.3% of patients died of cancers within 6 months after palliative surgery. A statistical analysis showed that a higher CRP/albumin ratio (odds ratio: 0.39; cut–off 0.409) and absence of postoperative adjuvant therapy (odds ratio: 7.15) were independent risk factors for poor survival. Our findings suggest the need for careful consideration to determine if palliative surgery is the best option for a patient with these negative prognostic factors, regardless of life expectancy predicted based on a prognosis score.

Abstract

Prediction of prognosis is a key factor in therapeutic decision making due to recent the development of therapeutic options for spinal metastases. The aim of the study was to examine predictive scoring systems and identify prognostic factors for 6–month mortality after palliative surgery. The participants were 75 patients with spinal metastases who underwent palliative surgery and had a minimum follow–up period of 1 year. Associations of actual survival with categories based on the revised Tokuhashi score and new Katagiri score were evaluated. Univariate and multivariate analyses were performed to identify prognostic factors for 6–month mortality after palliative surgery. The median actual survival period was longer than those predicted using the scoring systems. However, 21.3% of patients died of cancers within 6 months after surgery. A higher CRP/albumin ratio (odds ratio: 0.39; cut–off 0.409) and absence of postoperative adjuvant therapy (odds ratio: 7.15) were independent risk factors for 6–month mortality. There was no association of mortality with primary site, severity of sarcopenia, or other biomarkers. These results suggest that careful consideration is needed to determine whether palliative surgery is the best option for patients with a high preoperative CRP/albumin ratio and/or absence of postoperative adjuvant therapy, regardless of predictions made from scoring systems.