title: Application of Weibull model for survival of patients with gastric cancer.
abstract: BACKGROUND
  Researchers in the medical sciences prefer employing Cox model for survival analysis. In some cases, however, parametric methods can provide more accurate estimates. In this study, we used Weibull model to analyze the prognostic factors in patients with gastric cancer and compared with Cox.
  
  
  METHODS
  We retrospectively studied 1715 patients with gastric cancer. Age at diagnosis, gender, family history, past medical history, tumor location, tumor size, eradicative degree of surgery, depth of tumor invasion, combined evisceration, pathologic stage, histologic grade and lymph node status were chosen as potential prognostic factors. Weibull and Cox model were performed with hazard rate and Akaike Information Criterion (AIC) to compare the efficiency of models.
  
  
  RESULTS
  The results from both Weibull and Cox indicated that patients with the past history of having gastric cancer had the risk of death increased significantly followed by poorly differentiated or moderately differentiated in histologic grade. Eradicative degree of surgery, pathologic stage, depth of tumor invasion and tumor location were also identified as independent prognostic factors found significant. Age was significant only in Weibull model.
  
  
  CONCLUSIONS
  From the results of multivariate analysis, the data strongly supported the Weibull can elicit more precise results as an alternative to Cox based on AIC.
authors.affiliation: Department of Maternal and Child Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China.
authors.forename: Hui P
authors.initials: HP
authors.lastname: Zhu
authors.forename: Xin
authors.initials: X
authors.lastname: Xia
authors.forename: Chuan H
authors.initials: CH
authors.lastname: Yu
authors.forename: Ahmed
authors.initials: A
authors.lastname: Adnan
authors.forename: Shun F
authors.initials: SF
authors.lastname: Liu
authors.forename: Yu K
authors.initials: YK
authors.lastname: Du
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D047368:Tumor Burden; D055815:Young Adult