Researchers at Johns Hopkins has concluded that metastasis-free survival appeared to independently predictor of overall survival (OS) in men with recurrent prostate cancer who underwent androgen deprivation therapy (ADT) after developing metastases.
Men with biochemically recurrent prostate cancer (PSA only) tend to survive for long periods so the FDA gold standard for clinical trial endpoint of OS has proven to be a difficult endpoint to reach in clinical trials.
Consequently, researchers have long indicated the need for intermediate endpoints to help conduct these types of trials in a shorter time.
Emmanuel S. Antonarakis, MBBCh, of the Prostate Cancer Research Program at Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University School of Medicine, and colleagues conducted retrospective analysis of 450 men with recurrent prostate cancer.
All of the men had a prostatectomy at a single institution between 1981 and 2010. Additionally, androgen deprivation therapy (ADT) was deferred until after the men developed metastases.
Of the 450 men in the subject pool 140 of them developed metastases during the time being surveyed.
They found the following:
1- Median metastasis-free survival was 10.2 years (95% CI, 7.6-14)
2- Median OS after metastasis was 6.6 years (95% CI, 5.8-8.4).
They then used a multivariable Cox regression and identified four independent prognostic variables for OS:
1- Metastasis-free survival (HR=0.77; 95% CI, 0.63-0.94);
2- Bisphosphonate use (HR=0.60; 95% CI, 0.37-0.98);
3- Number of metastases (?3 vs. ?4; HR=0.50; 95% CI, 0.29-0.85); and
4- Pain (absent vs. present; HR=0.43; 95% CI, 0.25-0.72).
They concluded “Metastasis-Free Survival is an independent predictor of OS in men with biochemically recurrent prostate cancer treated with deferred ADT after the development of metastases,”
Hopefully, this research will be validated and the FDA will take note of the conclusions. “Metastasis-Free survival may be a reasonable intermediate endpoint in future clinical trials which would allow quicker clinical trial results.
Additionally, those of us with a biochemical recurrence can take some solace from this data as it appears that we will be hanging around for an extended period of time.
By the way, Dr. Antonarakis has a pending research project that you can support at Start A Cure (www.StartACure.com), our own crowd funding cancer research project for cancer survivors. His specific project is: “Who Will Respond to Abiraterone and Enzalumide”? This project looks to develop ways of determining which of these two drugs is more appropriate for an individual. Knowing this will allow us to receive the best drug immediately which will better control our disease and save the economy money by limiting the expense of giving non-effective drugs to anyone.
Joel T. Nowak, M.A., M.S.W.