Transcript Long-Term versus Short-Term Androgen Deprivation

Long-Term versus Short-Term Androgen Deprivation Combined
with High-Dose Radiotherapy for Intermediate and High Risk
Prostate Cancer: Preliminary Results of a Phase III Randomized
Trial - DART 01/05
A.Zapatero, A.Guerrero, X.Maldonado, A.Alvarez, C.González Sansegundo, A.Cabeza,
V.Macías, F.Casas. A. Pedro-Olivé, S.Villa, A.Boladeras, M.L. Vazquez de la Torre, C.
Martin de Vidales, F.A.Calvo. G.I.C.O.R.
This study has been supported by Governmental Grant No. 04/2506 fron the FIS (National Health Investigation
Fund – Fondo de Investigación Sanitaria)
• Background
1.
In locally advanced prostate cancer, randomized trials have shown a
significant benefit in OS when androgen deprivation (AD) and conventional
dose of radiotherapy (≤ 70-72 Gy) are associated.
2.
A GICOR study (JCO, 2005) showed and independent benefit of dose
escalation combined with AD in high-risk disease.
3.
The role and the optimal scheme of AD when associated to high-dose
radiotherapy remains controversial.
• Objectives / Purpose
To determine whether long-term AD (LTAD) is superior to short -term AD
(STAD) in intermediate and high-risk prostate cancer patients treated with
high-dose RT.
1.
Primary endpoint: Freedom from biochemical failure (FFBF). (Phoenix
definition)
2.
Secondary endpoints:
Freedom from clinical failure (FFCF)
Overall survival (OS)
Toxicity (RTOG and CTC criteria)
-Study designed to detect a difference in FFBF of 15% in favor
of 80% and a unilateral significance level of 5%.
-Sample size required including 15% loss: 358 patients
of LTAD with a statistical power
• Limitations of the study
 This study assumes the inherent limitations of an interim analysis report:
 Short follow-up
 Short number of events
 Absence of a control arm with HDRT alone ?
 FFBF less than optimal primary endpoint?
• Strenght of the study
 This is a pioneering study to evaluate the role of AD combined with highdose escalated RT (median 78 Gy) in prostate cancer.
• Conclusion
1. Although preliminary, the results of the study suggest that LTAD could be
superior to STAD in patients with unfavorable prostate cancer treated with
high-dose external beam radiotherapy.
2. Relevant radiation toxicity remains acceptably low and not significantly
different in both treatment arms.
3. Longer follow-up is required to confirm these trends.