title: Bias in reporting of randomised clinical trials in oncology.
abstract: Bias in reporting efficacy and toxicity in clinical trials may impact treatment decisions. Here, we report quality of reporting of efficacy and of toxicity in articles describing randomised controlled trials (RCTs) of cancer therapy and the association between biased reporting and study results, funding and financial relationships of the authors with the sponsor.
  
  
  
  We reviewed articles published from July 2010 to December 2012 in six high-impact journals reporting RCTs of systemic treatment for cancer. Bias in reporting of the primary end-point and toxicity were assessed. Associations between biased reporting and study results, funding source and financial ties of the author with the funding source were evaluated using logistic regression.
  
  
  
  Two hundred articles were identified. Among 107 RCTs where there was no statistically significant difference in the primary end-point between the two arms, 50 (47%) reports used biased reporting in the abstract of the paper to imply benefit of the experimental treatment. Toxicity was not reported in the abstract in 18.5% of the studies and this was associated with a positive primary end-point. Source of funding and financial ties were not associated with biased reporting.
  
  
  
  Bias in reporting of efficacy outcomes is common for studies with a negative primary end-point and can lead to off-label misuse of experimental therapies, if they are approved for other indications. Toxicity is under-reported, especially for studies with a positive primary end-point, leading to a biased view of the safety of new treatments.
authors.affiliation: Division of Medical Oncology & Hematology, Princess Margaret Cancer Centre, Department of Medicine, University of Toronto, 610 University Ave, Toronto M5G 2M9, Canada.
authors.forename: Francisco E
authors.initials: FE
authors.lastname: Vera-Badillo
authors.affiliation: Division of Medical Oncology & Hematology, Princess Margaret Cancer Centre, Department of Medicine, University of Toronto, 610 University Ave, Toronto M5G 2M9, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Napoleone
authors.affiliation: Division of Medical Oncology & Hematology, Princess Margaret Cancer Centre, Department of Medicine, University of Toronto, 610 University Ave, Toronto M5G 2M9, Canada.
authors.forename: Monika K
authors.initials: MK
authors.lastname: Krzyzanowska
authors.affiliation: Division of General Internal Medicine and Geriatrics, University Health Network, Department of Medicine, University of Toronto, 610 University Ave, Toronto M5G 2M9, Canada.
authors.forename: Shabbir M H
authors.initials: SM
authors.lastname: Alibhai
authors.affiliation: Women's College Hospital and Research Institute, Division of Dermatology, Department of Medicine, University of Toronto, 76 Grenville St, Toronto M5S 1B2, Canada.
authors.forename: An-Wen
authors.initials: AW
authors.lastname: Chan
authors.affiliation: Medical Oncology Department and Translational Research Unit, Albacete University Hospital, Calle Hermanos Falco, 37, Albacete 02006, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ocana
authors.affiliation: Sector of Medical Oncology, Institute of Oncology Ljubljana, University of Ljubljana, Zaloska cesta 2, Ljubljana 1000, Slovenia.
authors.forename: Bostjan
authors.initials: B
authors.lastname: Seruga
authors.affiliation: Department of Medical Oncology, Kantonsspital St Gallen, Rorschacher Str. 95, St. Gallen 9007, Switzerland.
authors.forename: Arnoud J
authors.initials: AJ
authors.lastname: Templeton
authors.affiliation: Division of Medical Oncology & Hematology, Princess Margaret Cancer Centre, Department of Medicine, University of Toronto, 610 University Ave, Toronto M5G 2M9, Canada.
authors.forename: Eitan
authors.initials: E
authors.lastname: Amir
authors.affiliation: Division of Medical Oncology & Hematology, Princess Margaret Cancer Centre, Department of Medicine, University of Toronto, 610 University Ave, Toronto M5G 2M9, Canada. Electronic address: Ian.Tannock@uhn.ca.
authors.forename: Ian F
authors.initials: IF
authors.lastname: Tannock
mesh_terms: D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015982:Bias; D002202:Capital Financing / Q000941:ethics; D016265:Conflict of Interest; D006801:Humans; D008495:Medical Oncology; D009369:Neoplasms / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic / Q000941:ethics / Q000592:standards*
chemical_list: D000970:Antineoplastic Agents
keywords: Bias; Conflicts of interest; Randomised clinical trials; Spin