What can we learn from oncology surgical trials?

Conducting high-quality prospective clinical trials in surgical oncology remains a challenge, and many seemingly well-designed trials lack this high quality because of inadequate recruitment accrual, lack of clinician interest, or evolution of treatment strategy during the many years over which such trials are conducted. In this Perspectives we examine some of the failures in published surgical oncology trials and discuss why they failed, and we make a critical assessment of the established prospective trial methodology in oncological practice (that is, phase 0, I, II, III and IV trials, and large prospective comparative audits) and how these methods might be used more effectively in future evaluation of cancer-surgery practice.