title: Application of accelerated failure time models for breast cancer patients' survival in Kurdistan Province of Iran.
abstract: BACKGROUND
  Breast cancer is the most common cancer and the second common cause of cancer-induced mortalities in Iranian women. There has been a rapid development in hazard models and survival analysis in the last decade.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the prognostic factors of overall survival (OS) in breast cancer patients using accelerated failure time models (AFT).
  
  
  METHODS
  This was a retrospective-analytic cohort study.
  
  
  METHODS
  About 313 women with a pathologically proven diagnosis of breast cancer who had been treated during a 7-year period (since January 2006 until March 2014) in Sanandaj City, Kurdistan Province of Iran were recruited.
  
  
  METHODS
  Performance among AFT was assessed using the goodness of fit methods. Discrimination among the exponential, Weibull, generalized gamma, log-logistic, and log-normal distributions was done using Akaik information criteria and maximum likelihood.
  
  
  RESULTS
  The 5 years OS was 75% (95% CI = 74.57-75.43). The main results in terms of survival were found for the different categories of the clinical stage covariate, tumor metastasis, and relapse of cancer. Survival time in breast cancer patients without tumor metastasis and relapse were 4, 2-fold longer than other patients with metastasis and relapse, respectively.
  
  
  CONCLUSIONS
  One of the most important undermining prognostic factors in breast cancer is metastasis; hence, knowledge of the mechanisms of metastasis is necessary to prevent it so occurrence and treatment of metastatic breast cancer and ultimately extend the lifetime of patients.
authors.affiliation: Social Determinants of Health Research Center, Kurdistan University of Medical Sciences, Sanandaj, IR Iran.
authors.forename: Asrin
authors.initials: A
authors.lastname: Karimi
authors.affiliation: Department of Epidemiology, Faculty of Health, Ilam University of Medical Sciences, Ilam, IR Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Delpisheh
authors.affiliation: Prevention of Psychosocial Injuries Foundation, Research Center, Ilam, IR Iran.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Sayehmiri
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D015233:Models, Statistical; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor