摘要：Abstract Background The International Committee of Medical Journal Editors (ICMJE) has developed guidelines for responsible and accountable authorship. Few studies have assessed the frequency and nature of ghost and honorary authorship in publications of oncology trials. Materials and methods Reports of randomised clinical trials evaluating systemic cancer therapy published from July 2010 to December 2012 in six high-impact journals were identified systematically. Ghost authorship was determined to be present in any scenario where investigators or statisticians listed in the protocol were not included as authors and not acknowledged in the report of the trial. The list of contributions for authors of published articles was recorded, and we defined an article as having an honorary author if any author did not meet all three criteria established by ICMJE in 1985. Results Two hundred publications were identified. For 61 articles, protocols with listed investigators were available, and 40 (66%) of these articles met our definition of ghost authorship. Medical writers were involved in 89 articles (45%), and assistance was acknowledged only in sponsored trials. Contributions of each author were provided in 195 articles, and 63 (33%) articles met our definition for honorary authorship. Funding source was not a predictor for either honorary or ghost authorship. Journal impact factor was positively associated with honorary authorship (odds ratio = 1.03; 95% confidence interval = 1.004–1.065; P = 0.03), but not with ghost authorship. Conclusion Ghost and honorary authorship are prevalent in articles describing trials for systemic therapy of cancer. Guidelines should be enforced to improve transparency and accountability.