TY - JOUR
T1 - Predictive factors of survival in a surgical series of metastatic epidural spinal cord compression and complete external validation of 8 multivariate models of survival in a prospective North American multicenter study
AU - Nater, Anick
AU - Tetreault, Lindsay A.
AU - Kopjar, Branko
AU - Arnold, Paul M.
AU - Dekutoski, Mark B.
AU - Finkelstein, Joel A.
AU - Fisher, Charles G.
AU - France, John C.
AU - Gokaslan, Ziya L.
AU - Rhines, Laurence D.
AU - Rose, Peter S.
AU - Sahgal, Arjun
AU - Schuster, James M.
AU - Vaccaro, Alexander R.
AU - Fehlings, Michael G.
N1 - Funding Information:
Branko Kopjar reports working as a consultant for Cerapedics and Smith and Nephew outside the submitted work. Paul M. Arnold reports other from Evoke Medical, CTL, Z-Plasty, SpineEx, and Asterias; personal fees and other from Stryker Spine, Ulrich, Spine Wave, and Medtronic; and personal fees from Stryker Orthopaedics, InVivo Therapeutics, and Medtronic Sofamor Danek outside the submitted work. Charles G. Fisher reports personal fees from Med-tronic and Nuvasive and grants from the Orthopaedic Research and Education Foundation outside the submitted work. Ziya L.Gokaslan reports being a shareholder in Spinal Kinetics and receiving honoraria from the AO Foundation outside the submitted work. Laurence D. Rhines reports other from Stryker and Medtronic outside the submitted work. Peter S. Rose reports personal fees from K2M outside the submitted work. Arjun Sahgal reports grants from Elekta AB; past educational seminars and travel accommodations from Elekta AB and Varian; and past educational seminars from Accuray outside the submitted work. Sahgal also belongs to the Elekta MR Linac Research Consortium. Alexander R. Vaccaro reports other from Advanced Spinal Intellectual Properties, AO Spine, Avaz Surgical, Bonovo Orthopaedics, Clinical Spine Surgery, Computational Biodynamics, Cytonics, Dimension Orthotics LLC, Electrocore, Flag-ship Surgical, FlowPharma, Franklin Bioscience, Gamma Spine, Insight Therapeutics, Jaypee, Paradigm Spine, Parvizi Surgical Innovation, Prime Surgeons, Progressive Spinal Technologies, Replication Medica, Rothman Institute and Related Properties, Spine Journal, Spine Medica, Spine Therapy Network, Inc, Spinology, and Verti-flex; personal fees from Aesculap, Atlas Spine, DePuy, Elsevier, Ger-son Lehrman Group, Guidepoint Global, Innovative Surgical Design, Medacorp, Medtronics, Orthobullets, Spine Wave, Stryker Spine, Taylor Francis/Hodder and Stoughton, and Thieme; and personal fees and other from Globus, Nuvasive, and Stout Medical outside the submitted work.
Funding Information:
Funding support was received from AOSpine North America to collect the data used in the AOSpine North America prospective metastatic epidural spinal cord compression study. Anick Nater received funding support from a Canadian Institutes of Health Research fellowship award. Michael G. Fehlings acknowledges support from the Gerald and Tootsie Halbert Chair in Neural Repair and Regeneration. The University of Texas MD Anderson Cancer Center is supported by the National Institutes of Health (grant P30 CA016672).
Publisher Copyright:
© 2018 American Cancer Society
PY - 2018/9/1
Y1 - 2018/9/1
N2 - BACKGROUND: This study was designed to identify preoperative predictors of survival in surgically treated patients with metastatic epidural spinal cord compression (MESCC), to examine how these predictors are related to 8 prognostic models, and to perform the first full external validation of these models in accordance with the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) statement. METHODS: One hundred forty-two surgically treated patients with MESCC were enrolled in a prospective, multicenter North American cohort study and were followed for 12 months or until death. Cox regression was used. Noncollinear predictors with < 10% missing data, with ≥ 10 events per stratum, and with P <.05 in a univariate analysis were tested through a backward stepwise selection. For the original and revised Tokuhashi prognostic scoring systems (PSSs), Tomita PSS, modified Bauer PSS, van der Linden PSS, Bartels model, Oswestry Spinal Risk Index, and Bollen PSS, this study examined calibration graphically, discrimination with Harrell c-statistics, and survival stratified by risk groups with the Kaplan-Meier method and log-rank test. RESULTS: The following were significant in the univariate analysis: type of primary tumor, sex, organ metastasis, body mass index, preoperative radiotherapy to MESCC, physical component (PC) of the 36-Item Short Form Health Survey, version 2 (SF-36v2), and EuroQol 5-Dimension (EQ-5D) Questionnaire. Breast, prostate and thyroid primary tumor (HR: 2.9; P =.0005), presence of organ metastasis (hazard ratio (HR): 2.0; P =.005) and SF-36v2 PC (HR: 0.95; P <.0001) were associated with survival in multivariable analysis. Predicted prognoses poorly matched observed values on calibration plots; Bartels model calibration slope was 0.45. Bollen PSS (0.61; 95% CI: 0.58-0.64) and Bartels model (0.68; 95% CI: 0.65-0.71) had the lowest and highest c-statistics, respectively. CONCLUSIONS: The primary tumor type (breast, prostate, or thyroid), an absence of organ metastasis, and a lower degree of physical disability are preoperative predictors of longer survival for surgical MESCC patients. These results are in keeping with current models. This full external validation of 8 prognostic PSSs or model of survival in surgical MESCC patients has revealed that calibration is poor, especially for long-term survivors, whereas discrimination is possibly helpful.
AB - BACKGROUND: This study was designed to identify preoperative predictors of survival in surgically treated patients with metastatic epidural spinal cord compression (MESCC), to examine how these predictors are related to 8 prognostic models, and to perform the first full external validation of these models in accordance with the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD) statement. METHODS: One hundred forty-two surgically treated patients with MESCC were enrolled in a prospective, multicenter North American cohort study and were followed for 12 months or until death. Cox regression was used. Noncollinear predictors with < 10% missing data, with ≥ 10 events per stratum, and with P <.05 in a univariate analysis were tested through a backward stepwise selection. For the original and revised Tokuhashi prognostic scoring systems (PSSs), Tomita PSS, modified Bauer PSS, van der Linden PSS, Bartels model, Oswestry Spinal Risk Index, and Bollen PSS, this study examined calibration graphically, discrimination with Harrell c-statistics, and survival stratified by risk groups with the Kaplan-Meier method and log-rank test. RESULTS: The following were significant in the univariate analysis: type of primary tumor, sex, organ metastasis, body mass index, preoperative radiotherapy to MESCC, physical component (PC) of the 36-Item Short Form Health Survey, version 2 (SF-36v2), and EuroQol 5-Dimension (EQ-5D) Questionnaire. Breast, prostate and thyroid primary tumor (HR: 2.9; P =.0005), presence of organ metastasis (hazard ratio (HR): 2.0; P =.005) and SF-36v2 PC (HR: 0.95; P <.0001) were associated with survival in multivariable analysis. Predicted prognoses poorly matched observed values on calibration plots; Bartels model calibration slope was 0.45. Bollen PSS (0.61; 95% CI: 0.58-0.64) and Bartels model (0.68; 95% CI: 0.65-0.71) had the lowest and highest c-statistics, respectively. CONCLUSIONS: The primary tumor type (breast, prostate, or thyroid), an absence of organ metastasis, and a lower degree of physical disability are preoperative predictors of longer survival for surgical MESCC patients. These results are in keeping with current models. This full external validation of 8 prognostic PSSs or model of survival in surgical MESCC patients has revealed that calibration is poor, especially for long-term survivors, whereas discrimination is possibly helpful.
KW - external validation
KW - metastatic epidural spinal cord compression
KW - predictive factors
KW - prospective study
KW - survival
UR - http://www.scopus.com/inward/record.url?scp=85050455305&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050455305&partnerID=8YFLogxK
U2 - 10.1002/cncr.31585
DO - 10.1002/cncr.31585
M3 - Article
C2 - 29975401
AN - SCOPUS:85050455305
SN - 0008-543X
VL - 124
SP - 3536
EP - 3550
JO - Cancer
JF - Cancer
IS - 17
ER -