Disease-free survival as an end-point in the treatment of solid tumours--perspectives from clinical trials and clinical practice.

Disease-free survival (DFS) is an end-point for an increasing number of clinical trials in adjuvant and curative intent cancer treatment informing both regulatory bodies and clinical practice. DFS is seen both as a surrogate end-point and as an end-point in itself in clinical trials. Understanding the history of DFS, and some of the assumptions, limitations, and vulnerabilities for studies designed with this primary end-point are required. This commentary reviews recent drug approvals for anti-cancer agents in solid tumours in the adjuvant and curative settings, and considers the meaning of DFS from the perspectives of clinical trials and clinical practice.