To investigate secular trends in article retractions in the oncology literature, particularly relating to cancer treatments and data available to patients. A bibliometric analysis of article retractions from PubMed in the period 2000-2018. Analysis shows that article lifetime - that is the time period from initial publication to ultimate retraction - has decreased in recent years. It also shows that the retraction rate has also increased over the same period. Furthermore, over 20% of retracted oncology publications analyzed in this study relate to treatment-relevant topics such as clinical trials and studies in the anticancer properties of supplements. The causes and context of these trends are discussed and reference made to the dangers of scientific misconduct in oncology.