The real-world benefits of adding androgen-deprivation therapy (ADT) and its optimal duration when combined with current standard high-dose radiation therapy (RT) remain unknown. We aimed to assess the efficacy of and toxicities associated with ADT in the setting of combination with high-dose RT for intermediate-risk (IR) and high-risk (HR) prostate cancer (PCa). This article is a modified and detailed version of the commentary on Clinical Question 8 described in the Japanese Clinical Practice Guidelines for Prostate Cancer (ver. 2023). A qualitative systematic review was performed according to the Minds Guide. All relevant published studies between September 2010 and August 2020, which assessed the outcomes of IR or HR PCa treated with high-dose RT, were screened using two databases (PubMed and ICHUSHI). A total of 41 studies were included in this systematic review, mostly consisting of retrospective studies (N = 34). The evidence basically supports the benefit of adding ADT to high-dose RT to improve tumor control. Regarding IR populations, many studies suggested the existence of a subgroup for which adding ADT had no impact on either overall survival or the BF-free duration. On the other hand, regarding HR populations, several studies suggested the positive impact of adding ADT for ≥1 year on overall survival. Adding ADT increases not only the risk of sexual dysfunction but also that of cardiovascular toxicities or bone fracture. Although the benefit of adding ADT was basically suggested for both IR and HR populations, further investigations are warranted to identify subgroups of patients for whom ADT has no benefit, as well as the appropriate duration of ADT for those who do derive benefit.

BACKGROUND: Hormone therapy, which is widely prescribed for prostate cancer, might induce cognitive impairment and affect the autonomy of elderly patients. However, previous studies provided conflicting results. The aim of this systematic review and meta-analysis was to synthesize the longitudinal impact of hormone therapy on objective (cognitive tests) and subjective (questionnaires) cognition.
METHODS: A search was performed of the PubMed, Web of Science, and PsycINFO databases. Studies that longitudinally assessed cognition in patients undergoing androgen-deprivation therapy and new-generation hormone therapy were considered. To perform a meta-analysis, available scores were aggregated and classified into six objective domains and one subjective domain. Weighted mean effect sizes were computed using a random effect model.
RESULTS: Twenty studies were included in the systematic review (1440 patients), and 15 could be included in the meta-analysis (1093 patients). In the systematic review, 20%-50% of patients had objective cognitive impairment before treatment initiation. The meta-analysis revealed a decline in subjective cognition (g = -0.44; p = .03) with androgen-deprivation therapy and new-generation hormone therapy. All other effect sizes were small (from g = -0.02 to g = 0.18), and none of them indicated a significant decline in objective cognition. Significant heterogeneity was observed in all domains of objective cognition.
CONCLUSIONS: This synthesis presents the first meta-analytic evidence of the negative impact of androgen-deprivation therapy and new-generation hormone therapy on subjective cognition. In contrast, there was no conclusive evidence of a decline in objective cognition. The high heterogeneity underscores the need for homogeneous cognitive research on prostate cancer.
CONCLUSIONS: There is no consensus on the cognitive impairment induced by hormone therapy for prostate cancer, despite the implications for patients\' care and daily life. This synthesis of published studies demonstrated an increase in perceived cognitive difficulties but did not prove a decline in cognitive performance during treatment.