title: Primary Spinal Tumor Mortality Score (PSTMS): a novel scoring system for predicting poor survival.
abstract: BACKGROUND
  Although the surgical and oncological therapies of primary spinal tumors (PSTs) have changed significantly over the last few decades, the prognosis of this rare disease is still poor. The decision-making process in the multidisciplinary management is handicapped by the lack of large-scale population-based prognostic studies.
  
  
  OBJECTIVE
  The objective of the present study was to investigate preoperative factors associated with PST mortality and to develop a predictive scoring system of poor survival.
  
  
  METHODS
  This is a large-scale ambispective cohort study.
  
  
  METHODS
  The study included 323 consecutive patients with PSTs, treated surgically over an 18-year period at a tertiary care spine referral center for a population of 10 million.
  
  
  METHODS
  Survival was the outcome measure.
  
  
  METHODS
  Patients were randomly divided into a training cohort (n=273) and a validation cohort (n=50). In the training cohort, 12 preoperative factors were investigated using Cox proportional hazard models. Based on the mortality-related variables, a simple scoring system of mortality was created, and three groups of patients were identified. Kaplan-Meier and log-rank analyses were used to compare the survival in the three groups. The model performance was assessed by measuring the discriminative ability (c-index) of the model and by applying a pseudo-R(2) goodness-of-fit test (Nagelkerke R(2), RN(2)). Internal validation was performed using bootstrapping in the training cohort and assessing the discrimination and explained variation of the model in the validation cohort.
  
  
  RESULTS
  Patient age, spinal region, tumor grade, spinal pain, motor deficit, and myelopathy/cauda equina syndrome were significantly associated with poor survival in the multivariate analysis (p<.001, RN(2)=0.799). Based on these variables, we developed the Primary Spinal Tumor Mortality Score (PSTMS), where an eight-point scale was divided into three categories (low, medium, and high mortality). The three PSTMS categories were significantly associated with the overall survival (p<.001, RN(2)=0.811, c=0.82). The model performance remained similarly high in the validation cohort (RN(2)=0.831, c=0.81).
  
  
  CONCLUSIONS
  The present study identifies six predictive variables for mortality in PSTs. Using these six variables, an easy-to-use scoring system was developed that can be applied to the estimation of postoperative survival in all types of PST patients.
authors.affiliation: National Center for Spinal Disorders, Kiralyhagó St 1-3, Budapest 1126, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Szövérfi
authors.affiliation: National Center for Spinal Disorders, Kiralyhagó St 1-3, Budapest 1126, Hungary.
authors.forename: Aron
authors.initials: A
authors.lastname: Lazary
authors.affiliation: National Center for Spinal Disorders, Kiralyhagó St 1-3, Budapest 1126, Hungary.
authors.forename: Árpád
authors.initials: Á
authors.lastname: Bozsódi
authors.affiliation: National Center for Spinal Disorders, Kiralyhagó St 1-3, Budapest 1126, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Klemencsics
authors.affiliation: National Center for Spinal Disorders, Kiralyhagó St 1-3, Budapest 1126, Hungary.
authors.forename: Péter E
authors.initials: PE
authors.lastname: Éltes
authors.affiliation: National Center for Spinal Disorders, Kiralyhagó St 1-3, Budapest 1126, Hungary. Electronic address: vpp@bhc.hu.
authors.forename: Péter Pál
authors.initials: PP
authors.lastname: Varga
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D017063:Outcome Assessment, Health Care; D011184:Postoperative Period; D011379:Prognosis; D013125:Spinal Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D013131:Spine / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult
keywords: Mortality; Prognosis; Prognostic factors; Proportional hazards models; Spinal neoplasms; Surgery; Survival analysis