Objective: To characterize the clinical outcomes of androgen deprivation therapy (ADT) as the sole therapy for localized prostate cancer, and to determine independent predictors of disease progression, as recent studies indicate an increasing use of ADT.
Patients and methods: The records of all patients with cT1-4NXM0 adenocarcinoma of the prostate treated with ADT as the primary initial therapy at the Portland Veterans Affairs Medical Center between 1993 and 2000 were reviewed. Age, race, Charlson Health Index, family history, prostate-specific antigen (PSA) level, PSA density, digital rectal examination (DRE) findings, Gleason score, and percentage of positive biopsy cores at diagnosis were recorded for 81 patients. Patients had a median (SD, range) age of 73 (5.6, 58-84) years, a PSA level of 14.3 (34.6, 1.4-252) ng/mL and tumours were classified as Gleason score < or = 5 in 9% of patients, 6 in 31%, 7 in 31% and 8-10 in 30%. Outcomes extracted were PSA progression, PSA nadir, bone fractures, local progression, distant progression and overall survival.
Results: With a median (range) follow-up of 54 (6-115) months, the incidence of local progression, distant progression, bone fractures, PSA progression, and death were 10%, 7%, 25%, 21% and 41% respectively. The percentage of positive biopsy cores > or = 83%, age < 70 years, Gleason score > or = 7, abnormal DRE, and PSA nadir > or = 0.2 ng/mL were significantly associated with PSA progression by univariate analysis. The multivariate analysis identified age < 70 years (hazard ratio 6.52, 95% confidence interval 2.29-18.55) and Gleason score > or = 6 (4.0, 2.0-12.0) as independent risk factors for PSA progression.
Conclusions: ADT resulted in modest control of localized prostate cancer, but younger patients and those with Gleason > or = 6 cancers were at higher risk of treatment failure. Toxicity, principally in the form of bone fractures, was high.