title: [Primary and secondary outcomes in oncology clinical trials: definitions and uses].
abstract: BACKGROUND
  The proof of efficacy from a therapeutic intervention in oncology must be defined through well conducted clinical trials. One of the most important methodological issue is the outcome selection needed to calculate measures of association allowing definition of clinical efficacy.
  
  
  METHODS
  We designed a narrative revision based on some of the international regulatory instructions from drug agencies, as well as consensus papers from scientific oncology societies, listing and critically assessing each outcome used in oncology clinical trials.
  
  
  RESULTS
  We identified as being the most important outcomes in oncology trials the overall survival, the progression free survival/ disease-free survival, the toxicity, the quality of life/patient-reported outcomes and the objective response rate.
  
  
  CONCLUSIONS
  The selection of the primary outcome must be based on therapeutic efficacy as well as toxicity, expected survival, alternative drug regimens and even disease prevalence.
  
  
  CONCLUSIONS
  The selection of efficacy outcomes for clinical trials in oncology is very important and its selection must be well justified, and depends on the type of disease, the patients and the drug being studied.
authors.affiliation: Centro de Estudos de Medicina Baseada na Evidência. Faculdade de Medicina. Universidade de Lisboa. Lisboa. Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Vaz-Carneiro
authors.affiliation: Centro de Estudos de Medicina Baseada na Evidência. Faculdade de Medicina. Universidade de Lisboa. Lisboa. Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Luz
authors.affiliation: Centro de Estudos de Medicina Baseada na Evidência. Faculdade de Medicina. Universidade de Lisboa. Lisboa. Portugal.
authors.forename: Margarida
authors.initials: M
authors.lastname: Borges
authors.affiliation: Centro de Estudos de Medicina Baseada na Evidência. Faculdade de Medicina. Universidade de Lisboa. Lisboa. Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Costa
mesh_terms: D006801:Humans; D009369:Neoplasms / Q000628:therapy*; D063868:Patient Outcome Assessment; D016032:Randomized Controlled Trials as Topic