External beam radiation therapy or high intensity-focused ultrasound for localized prostate cancer: A matched pair analysis in the prostate-specific antigen era.

Abstract

109 Background: In the absence of randomised study data institutional series have shown High Intensity Focused Ultrasound (HIFU) to produce excellent overall and cancer specific survival rates in patients with localized prostate cancer (LPCa) compared with alternative curative treatments. The aim of this study was to evaluate the oncologic outcome of patients treated with HIFU versus conformal external beam radiation therapy (C-EBRT) without previous or associated androgen deprivation(AD).This study was designed to overcome limitations of case series studies by using a matched pair design in patients treated contemporaneously with HIFU and C- EBRT in two institutions in the same town. Methods: 256 eligible patients with intermediate risk prostate cancer (d’Amico classification) treated between 2000 and 2005 were prospectively followed and matched to a 1:1 basis following know prognostic variables: prostate-specific antigen (PSA) level and Gleason score.190 perfect matches of patients (95 in each group) were further analysed. Progression free survival rate were the primary endpoint. Other endpoints were secondary used of salvage therapy, and survival rate without salvage palliative androgen deprivation therapy (S-ADT).The progression free survival rates were calculated with Kaplan-Meier estimate. For progression free calculation, failure was defined using the Phoenix definition (nadir + 2ng/ml) or at the time of a salvage treatment for local relapse evidenced by control biopsy. Results: The seven years progression free survival rate was not significantly different after HIFU than after C-EBRT (47% versus 52%, p: 0.311) . The palliative androgen deprivation free rate at seven years was significantly different after HIFU than after C-EBRT (85% versus 58%, p: 0.002). Conclusions: The progression free survival rate was not significantly different after HIFU use than after C-EBRT but the rate of patients who need palliative S-ADT was significantly different after HIFU or C-EBRT: Higher rate of S-ADT was associated with C-EBRT use than with HIFU use.