The Definition for the Assessment of Time-to-event Endpoints in CANcer trials (DATECAN initiative), recently published in the Annals of Oncology the guidelines for time-to-event end point definitions in breast cancer trials.

In randomized cancer clinical trials (RCTs), the validated and most objectively defined evaluation criterion is overall survival (OS), characterized as the time from randomization to patients’ death (all causes). However, the definition of several of these time-to-event (TTE) end points are inaccurate limiting the interpretation and cross-trial comparisons. The estimation of treatment effects may be directly affected by the definitions of end points

Using a formal consensus process, statisticians and methodologists from UNICANCER under the leadership of the EORTC (European Organisation for Research and Treatment of Cancer) set up the international DATECAN initiative, which intends to obtain standardized consensus definitions of TTE end points for multiple cancer sites: breast; sarcomas/gastro intestinal stromal tumors (GISTs); pancreas; stomach/esophagus; head and neck; colon/rectum; kidney/bladder; and lung cancers.

Prof. Franck Bonnetain noted in a recent news release, “DATECAN should help us to elaborate recommendations that can then be used as guidelines by researchers participating in clinical trials. For this purpose, we are using a formal consensus process to obtain standardized consensus definitions of time-to-event end points for several cancer types: pancreas, breast, sarcoma/GIST, stomach, esophagus, head and neck, colon, rectum, kidney, bladder, and lung (Bellera CA, Pulido M, Gourgou S, et al. Eur J Cancer 2013). Our most recent publication focuses on the definition of time-to-event end points, as primary or secondary end points, used in randomized clinical trials for patients with breast cancer in non-metastatic and metastatic settings.”

Dr. Sophie Gourgou, corresponding author of the DATECAN guidelines added in the news release, “Overall survival is often the endpoint used for cancer clinical trials, but today, end points such as disease-free survival are becoming increasingly common. One reason for this is that treatments are now more effective, especially in breast cancer, mortality is lower, and other measures of a treatment’s efficacy are needed. The problem is, these newer “time-to-event” end points are not well defined, so our ability to interpret results and make cross-trial comparisons is compromised.”

According to the researchers, the use of standardized definitions intends to compare the results of clinical trials and to improve the quality of overall trial methodology and reporting.