Overall survival (OS)
The gold standard for establishing clinical benefit and regulatory approval of new anti-cancer drugs in NSCLC1
OS is defined as the time from trial recruitment to death from any cause. Trial recruitment may be defined as the date of initial disease diagnosis or the date of treatment initiation.1,2
As a lifespan interval, OS is still accepted as the most clinically relevant and convincing endpoint that measures the clinical benefit of a treatment in its totality, provided QoL (which includes treatment-related adverse events) is still reasonably preserved.1,2
The advantages of OS are unequivocal, as this endpoint can be assessed with 100% accuracy in terms of occurrence and timing, presuming the number of patients lost to follow-up is not substantial.2 PFS is believed to be a viable and necessary alternative to OS in molecularly selected cancer populations where advantages of targeted therapies are difficult to assess due to crossover.2
5-year survival in patients with NSCLC has only marginally increased over the last decade, from 15.7% to 17.4%3
HRQoL: health-related quality of life; NSCLC: non-small-cell lung cancer; OS: overall survival; PFS: progression-free survival; QoL: quality of life.
1. Pilz LR, et al. Statistical considerations and endpoints for clinical lung cancer studies: can progression free survival (PFS) substitute overall survival (OS) as a valid endpoint in clinical trials for advanced non-small-cell lung cancer? Transl Lung Cancer Res. 2012;1:26–35.
2. Villaruz LC, Socinski MA. The Clinical Viewpoint: Definitions, Limitations of RECIST, Practical Considerations of Measurement. Clin Cancer Res. 2013;19:2629–36.
3. Boolell V, et al. The evolution of therapies in non-small cell lung cancer. Cancers (Basel). 2015;7:1815–46.