Introduction: We aimed to identify preoperative predictors of survival in Metastatic Epidural Spinal Cord Compression (MESCC) patients surgically treated, examine how these predictors relate to eight prognostic models; and to perform the first full external validation of these models in accordance to the TRIPOD statement.
Methods: 142 surgically treated MESCC patients were enrolled in a prospective, multicenter, North American, cohort study and followed for 12 months or until death. Cox proportional hazards (PH) regressions were used. Non-collinear predictors with <10% missing data, =10 events per stratum and p<0.05 in univariable analysis were tested through a backward stepwise selection. For the original and revised Tokuhashi, Tomita, modified Bauer, van der Linden, Bartels, OSRI and Bollen, we examined calibration graphically, discrimination with Harrell c-statistics and survival stratified by risk groups with the Kaplan-Meier method and log-rank test.
Results: Type of primary tumor, sex, organ metastasis, body mass index, preoperative radiotherapy to MESCC, and SF-36v2 Physical Component (PC) and EQ-5D were significant in the univariable analysis. Primary tumor, organ metastasis and SF-36v2 PC were associated with survival and corrected discrimination was 0.68 (95% CI: 0.66-0.70). Bartels had the best discrimination (0.68; 95% CI: 0.65 – 0.71).
Conclusions: Primary tumor type (breast, prostate and thyroid), absence of organ metastasis, and a lower degree of physical disability are preoperative predictors of longer survival in surgical MESCC patients. These results are in keeping with current models. This full external validation of eight prognostic models of survival in surgical MESCC patient revealed that calibration was poor, especially for long-term survivors, while discrimination was possibly helpful.
Patient Care: It will (1) identify key preoperative predictors of survival in patients with MESCC and (2) provide evidence supporting or not the use of clinical prediction models to predict survival in patients with MESCC to help guide physicians and patients in the joint therapeutic decision-making process.
Learning Objectives: 1) to identify key preoperative clinical factors associated with overall survival in adult patients treated surgically for a single metastatic epidural spinal cord compression (MESCC) lesion following the methodology highlighted by the TRIPOD statement
2) to examine how these preoperative predictors relate to current prognostic scoring systems (PSSs) or models of survival developed using retrospective data from MESCC patients who underwent surgery and/or RT
3) to perform the first full external validation and compare the performance of the following PSSs or models: modified Bauer, original and revised Tokuhashi, Tomita, Van der Linden, Bartels, ORSI, and Bollen fulfilling the TRIPOD checklist.