Intermittent androgen suppression in patients with prostate cancer.

Abstract

To evaluate intermittent androgen suppression (IAS) in patients with prostate cancer and to try to define predictive factors for biochemical progression. From 1989 to 2001, 146 patients received IAS as a primary treatment for localized, advanced or metastatic prostate cancer (72 men) or as a treatment for prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP) and/or radiation therapy (74 men). Androgen-deprivation treatment (ADT) was continued up to 6 months after PSA became undetectable or a nadir PSA level was reached. ADT was then re-instituted when the PSA level was> 4 ng/mL for patients who had RP or> 10 ng/mL for the others. After a mean (range) follow-up of 45.6 (12-196.9) months, 24 patients had biochemical progression. These patients were younger than those with no biochemical progression (67 vs 72 years, P = 0.004) and had a statistically higher Gleason score (7.21 vs 6.52, P = 0.01) and PSA level (111.1 vs 32.1 ng/mL, P = 0.05), and a shorter first phase without treatment (7.6 vs 11.2 months, P = 0.05). Overall 5-year metastatic disease free survival of 91.3%. The overall 5-year biochemical recurrence-free survival was 68%. Using multivariate analysis, a Gleason score of >or= 8 (P = 0.021), first-phase duration with no treatment of < 1 year (P = 0.044), positive lymph nodes or metastatic disease at the time of starting IAS (P = 0.023) and age < 70 years (P = 0.037) were the strongest predictors of biochemical progression. IAS appeared to be a feasible treatment; the best candidates being those aged> 70 years with localized prostate cancer and a Gleason score of <or= 7.