Changes in prostate-specific antigen and hormone levels following withdrawal of prolonged androgen ablation for prostate cancer

We conducted a study in order to characterize changes after withdrawal of androgen ablation (AA) for prostate cancer. AA was withdrawn in 38 Japanese patients with prostate cancer who had undergone this therapy for various periods. Patients were stratified into those who had undergone AA for less than 24 months (Group 1, n=12) and those with longer periods of AA (Group 2, n=26). Serial changes in hormones and prostate-specific antigen (PSA) were prospectively monitored following cessation of AA. The median durations of AA in the two groups were 8.5 and 54.5 months, respectively. Levels of total testosterone (T), luteinizing hormone and PSA increased significantly with time. At the end of 2 y, 30/38 patients (78.9%) had T levels above 50 ng/dl and 19/38 (50%) had levels above 320 ng/dl. Patients in Group 2 required significantly longer duration for T recovery. Complete T recovery is not always accompanied by rising PSA. Recovery of T levels is often slow following cessation of prolonged AA. Expression of PSA after AA is often variable and unpredictable. Thus, interpretation of outcomes in clinical trials incorporating AA needs caution and careful consideration.