Efficacy of Short-Term Androgen Deprivation With High-Intensity Focused Ultrasound in the Treatment of Prostate Cancer in Japan

Abstract

To determine whether combining short-term neoadjuvant androgen deprivation therapy (NADT) with high-intensity focused ultrasound (HIFU) had a significant benefit in a large population of men with nonmetastatic prostate cancer (CaP). We evaluated the records of 530 patients whose prostate-specific antigen (PSA) level at diagnosis was 30 ng/mL or less and whose follow-up period was not less than 12 months, at seven investigational sites. Two hundred seventy patients had received NADT (within 6 months), and 260 had not. The primary outcome measure was disease-free survival according to the combined criteria satisfying the Phoenix definition (less than nadir + 2), negative prostate biopsy, and no findings of distant metastasis after the last HIFU treatment. The significance of the differences of values or the distributions of each parameter between two groups was evaluated with a Mann-Whitney U test, unpaired t test, or chi-square test, and a multivariate Cox proportional hazards model was used to evaluate the prognostic relevance of preoperative parameters. Statistical analyses showed that the NADT group had worse disease (higher PSA and risk group) than the HIFU-only group. Variables shown by multivariate analyses to be significant prognostic parameters were pretreatment PSA level, clinical stage, and no use of NADT. Short-term NADT significantly improved the 3-year disease-free survival rate of patients with intermediate-risk and high-risk CaP. During follow-up the frequencies of complications did not differ significantly with or without NADT. Our retrospective study suggests that combining short-term NADT with HIFU treatment is of significant clinical benefit to intermediate-risk and high-risk CaP patients without increasing the likelihood of complications.