title: Time-varying predictors for clinical surveillance of small hepatocellular carcinoma.
abstract: OBJECTIVE
  Prognosis of small hepatocellular carcinoma depends on a constellation of time-varying predictors in association with liver function. We aimed to elucidate the impact of these time-dependent predictors on survival.
  
  
  METHODS
  A total of 108 patients with hepatocellular carcinoma smaller than 5 cm in diameter were recruited. Series of laboratory data and clinical assessments were retrieved from medical records. The time-dependent scoring system for the prediction of death was developed in accordance with a time-dependent Cox regression model.
  
  
  RESULTS
  Time trends for biologic predictors parallel cumulative survival of small hepatocellular carcinoma cases. Higher serum alpha-fetoprotein level was identified as the most significant time-dependent predictor. Other significant predictors included aspartate transaminase, bilirubin, alkaline phosphatase, and albumin levels and prothrombin time. Time-dependent surveillance scoring system shows the cutoff points of scores at 6 months, 1 year, 2 years, and 3 years were 42, 21, 19, and 31, respectively; the estimates of sensitivity, 100%, 100%, 100%, and 87.5%, respectively; and the estimates of specificity, 91.26%, 67.02%, 60.27%, and 78.26%, respectively. Predictive validity for this time-dependent Cox regression model, particularly within 1-year of follow-up, is good.
  
  
  CONCLUSIONS
  The dynamic relationships between time-dependent predictors and risk of death were illustrated. A time-dependent predictive scoring system using these dynamic relationships was developed for real-time surveillance.
authors.affiliation: Department of Internal Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
authors.forename: Chao-Sheng
authors.initials: CS
authors.lastname: Liao
authors.forename: Kuo-Ching
authors.initials: KC
authors.lastname: Yang
authors.forename: Ming-Fang
authors.initials: MF
authors.lastname: Yen
authors.forename: Tony
authors.initials: T
authors.lastname: Hsiu-Hsi Chen
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology*; D008962:Models, Theoretical; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D013997:Time Factors; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D000509:alpha-Fetoproteins