SURVIVAL OF PATIENTS WITH HORMONE REFRACTORY PROSTATE CANCER IN THE PROSTATE SPECIFIC ANTIGEN ERA

Abstract

Purpose: The historically reported 12 to 18-month duration of survival of patients with hormone refractory prostate cancer is not consistent with current clinical experience. Furthermore, to our knowledge patient survival after serum prostate specific antigen (PSA) progressively increases from a nadir despite castrate testosterone has not been previously reported. For this reason we studied overall survival and the clinical variables that influence survival in patients with hormone refractory prostate cancer. Materials and Methods: The study focused on 254 patients with prostate cancer on androgen deprivation therapy. Hormone refractory prostate cancer was defined as the first in a series of PSA elevations despite castrate levels of testosterone. The duration of survival in the hormone refractory phase was calculated from the date of the first PSA elevation to the date of death. Results: Median survival after hormone refractory prostate cancer developed in patients initially staged with and without skeletal metastasis was 40 and 68 months, respectively. Six of more than 25 input variables were retained as significant in the final Cox model. Variables associated with longer survival were lower nadir PSA, younger age, higher pretreatment testosterone, no history of obstructive uropathy, no history of tobacco use (past or current) and lower alkaline phosphatase. Conclusions: Historical reports of survival in hormone refractory prostate cancer underestimate current survival observations. The likely explanations of this observation include delayed enrollment in clinical trials from which most survival data are derived, PSA lead time in staging and improved supportive care. Models predicting survival in patients with hormone refractory prostate cancer should consider multiple variables.