Purpose: We compared biochemical control and quality of life with intermittent (6 months) versus continuous (36 months) androgen deprivation therapy (ADT) in a non-inferiority randomized phase 3 trial in patients with biochemical failure (BF) after external beam radical radiotherapy (EBRT).
Materials and methods: Patients were stratified according to the Gleason score (GS) and were classified as low risk with a GS < 6 and 7 (3 + 4) and high risk with a GS of 7 (4 + 3) and >7. Patients were followed with PSA determinations and quality-of-life assessments (QLQ C-30 and QLQ PR-25) every 6 months for a period of 3 years. BF after radiation was defined as a PSA level of nadir +2 ng/ml. Disease progression (DP) after ADT was defined as PSA ≥4 ng/ml (BF) and/or metastases.
Results: Seventy-seven patients were included in this multicenter phase 3 trial from 2005 to 2009. Thirty-eight and 39 patients were included in the intermittent and continuous groups, respectively. The median follow-up for both groups was 48 months (40-68). DP after ADT in the intermittent group was seen in three patients (distant metastases in one patient) versus 0 in the continuous group. The QLQ-C30 and QLQ PR-25 scores did not show any statistically difference between the two ADT groups.
Conclusions: No significant differences were seen in DP and QLQ between intermittent (6 months) and continuous (36 months) ADT in patients with BF after EBRT.
Keywords: External beam radiotherapy; Intermittent androgen deprivation therapy; Prostate cancer.