Background
Event-free survival (EFS) endpoints are composite endpoints frequently used in cancer gene expression studies to evaluate the effects of gene expression on patient outcomes. Event free Survival endpoints in oncology, such as Overall survival, typically combine both cancer-specific ‘death from cancer’ and non-cancer specific events ‘death from other causes’. Reporting analysis on each event comprising the composite endpoint is necessary to draw more specific inferences regarding outcomes, especially in the presence of competing risks. The extent to which cancer-specific and non-specific events are separated in contemporary gene expression studies in oncology is unknown.