Continuous vs. intermittent androgen deprivation therapy for metastatic prostate cancer

Abstract Objectives To analyze the predictive value of PSA for progression and the role of testosterone for quality of life (QOL) in patients with androgen deprivation therapy (ADT) for metastatic prostate cancer. Materials and methods PSA and testosterone data were used from a phase III trial randomizing patients without progression and PSA n = 193), after 6 months induction course, between continuous (CAD) ( n = 96) and intermittent (IAD) ( n = 97) ADT. The 2-year risk of progression was calculated for baseline PSA, ‘fast’ and ‘slow’ PSA decline to Results For progression analysis, 173 patients' data were available. The 2-year risk of progression for baseline PSA P = 0.03) in CAD, and 38%, 64%, and 85% ( P = 0.006) in IAD, respectively. The 2-year risk of progression for PSA nadir ≤ 0.2 ng/ml, and > 0.2 to 4 ng/ml in CAD was 31% and 70% ( P P = 0.03), respectively. PSA decline showed no predictive value. Patients without pain had a significantly lower 2-year risk of progression in both groups. Without ADT testosterone remained at castrate level for 4 months. After the first and second IAD cycle 92% and 46%, respectively, had a normalized testosterone. No QOL difference was found, although more side effects occurred in CAD. Conclusions Metastatic prostate cancer patients with high baseline PSA, pain, and high PSA nadir have a poor prognosis with ADT. Patients with low PSA nadir do significantly worse with IAD compared with CAD. Low testosterone after ADT and incomplete testosterone recovery may explain similar QOL. Therefore, IAD is not a good treatment option for many metastatic prostate cancer patients.