Metastasis-free Survival: a Surrogate for OS in Localized Prostate Cancer

Researchers can use metastasis-free survival as a surrogate end point for overall survival in clinical trials evaluating patients with localized prostate cancer, according to a study presented at the European Society for Medical Oncology (ESMO) 2016 Congress.¹

Although treatment advances in localized prostate cancer have reduced the risk of recurrence and improved overall survival, the Intermediate Clinical Endpoints in Localized Prostate Cancer Working Group attempted to identify end points that correlate with overall survival in localized prostate cancer clinical trials.

For this meta-analysis, investigators analyzed data from 12,712 men included in 19 mature randomized clinical trials conducted between 1987 and 2010. Of those, 90% were from radiotherapy-based studies, 30% had intermediate-risk disease, and 57% had high-risk disease. The majority of patients were less than 75 years old.

Researchers defined metastasis-free survival as the “time from randomization to the first evidence of distant metastatic disease, excluding pelvic lymph nodes, or death from any cause,” and overall survival as the “time from randomization to death from any cause.”

There were 5733 metastasis-free survival events and 5350 overall survival events, whereas there were 2154 time to metastasis events and 1460 disease-specific survival events. The latter 2 measurements did not include non-prostate cancer-related deaths.

Correlative analyses demonstrate that metastasis-free survival can be used as a surrogate end point for overall survival and time to metastasis can be used as a surrogate of disease-specific survival.                       

Reference

1. Xie W, Sweeney C, Regan M, et al. Metastasis free survival (MFS) is a surrogate for overall survival (OS) in localized prostate cancer (CaP). Paper presented at: European Society for Medical Oncology (ESMO) 2016 Congress; October 7-11, 2016; Copenhagen, Denmark.