Assessment of permanent brachytherapy combined with androgen deprivation therapy in an intermediate-risk prostate cancer group without a Gleason score of 4 + 3: a single Japanese institutional experience

Abstract

Objectives: To evaluate the outcome of low-dose-rate permanent brachytherapy combined with anti-androgen deprivation therapy for intermediate-risk prostate cancer excluding biopsy Gleason score 4 + 3.

Methods: Patients included in the intermediate-risk group were those presenting clinical stage T1c to T2c (by magnetic resonance imaging staging), Gleason score 3 + 4 or lower and/or prostate-specific antigen less than 20 ng/mL, whereas those with clinical stage T1c to T2a, Gleason score 3 + 3 and prostate-specific antigen less than 10 ng/mL represented the low-risk group, and were used as controls. In the intermediate-risk group, therapy with a luteinizing hormone-releasing hormone analog was continued for at least 6 months before and after permanent brachytherapy.

Results: A total of 147 low-risk group patients and 139 intermediate-risk group patients were included in the study. The median follow up was 51 and 52 months for the intermediate-risk group and low-risk group, respectively. The 5-year overall, cause-specific and distant-metastasis-free survival rates in the low-risk group and intermediate-risk group were 97.6/99.2, 100/100 and 100/100%, respectively. The 5-year biochemical disease-free survival in these groups were 95.9 and 92.5%, respectively (P = 0.18). There was no sexual activity and desire for erection before treatment in 50%, and in 46% of the patients in the low-risk group and intermediate-risk group, respectively. Overall satisfaction score at 2 years after permanent brachytherapy significantly improved, compared with pretreatment (P = 0.0399).

Conclusions: In intermediate-risk prostate cancer, excluding biopsy Gleason score 4 + 3, permanent brachytherapy combined with androgen deprivation therapy for 6 months or more represents an effective treatment option in Japanese patients, based on a favorable prognosis, adverse event profile and quality of life analysis.

Keywords: anti-androgen deprivation therapy; intermediate risk; outcome; permanent brachytherapy; prostate cancer.