Treatment
Overall Survival
Also known as: OS, Survival, Overall survival rate
Definition
The length of time from treatment start that patients remain alive, the gold standard endpoint in cancer trials.
Detailed Explanation
Overall survival (OS) is the most meaningful clinical trial endpoint because it directly measures how long patients live. Unlike PFS, OS can't be influenced by how or when disease progression is measured. Immunotherapy has shown unprecedented OS benefits in melanoma, lung cancer, and other malignancies, with some patients alive 10+ years after treatment.