Using PSA to Guide Timing of Androgen Deprivation in Patients with T0-4 N0-2 M0 Prostate Cancer Not Suitable for Local Curative Treatment (EORTC 30891)

Objective: EORTC trial 30891 compared immediate versus deferred androgen-deprivation therapy (ADT) in T0-4 N0-2 M0 prostate cancer (PCa). Many patients randomly assigned to deferred ADT did not require ADT because they died before becoming symptomatic. The question arises whether serum prostate-specific antigen (PSA) levels may be used to decide when to initiate ADT in PCa not suitable for local curative treatment.

Methods: PSA data at baseline, PSA doubling time (PSADT) in patients receiving no ADT, and time to PSA relapse (>2 ng/ml) in patients whose PSA declined to <2 ng/ml within the first year after immediate ADT were analyzed in 939 eligible patients randomly assigned to immediate (n=468) or deferred ADT (n=471).

Results: In both arms, patients with a baseline PSA>50 ng/ml were at a>3.5-fold higher risk to die of PCa than patients with a baseline PSA<or=8 ng/ml. If baseline PSA was between 8 and 50 ng/ml, the risk of PCa death was approximately 7.5-fold higher in patients with PSADT<12 mo than in patients with PSADT>12 mo. Time to PSA relapse after response to immediate ADT correlated significantly with baseline PSA, suggesting that baseline PSA may also reflect disease aggressiveness.

Conclusions: Patients with a baseline PSA>50 ng/ml and/or a PSADT<12 mo were at increased risk to die from PCa and might have benefited from immediate ADT, whereas patients with a baseline PSA<50 ng/ml and a slow PSADT (>12 mo) were likely to die of causes unrelated to PCa, and thus could be spared the burden of immediate ADT.