The role of androgen deprivation therapy prior to radical prostatectomy in high-risk prostate cancer: a systematic review

INTRODUCTION

Patients with high-risk prostate cancer (HRPCa) are prone to have worse pathological features, resulting in early biochemical recurrence after radical prostatectomy (RP). There is an urgent need to develop novel treatment strategies for this group of patients to optimize their outcomes. The purpose of this study is to perform a systematic review of the role of neoadjuvant hormonal therapy (NHT) followed by RP in HRPCa patients.

EVIDENCE ACQUISITION

We performed a systematic review of the following databases, MEDLINE (PubMed), EMBASE, Cochrane Library, and clinical Trial.gov; between January 2007 and August 2023, following the PRISMA guidelines.

EVIDENCE SYNTHESIS

After screening and deduplication, we included ten studies from an initial pool of 1275. The risk of bias was low in observational studies but ranged from moderate to low in controlled trials. Five studies utilized traditional androgen deprivation treatments (ADT), revealing favorable pathological outcomes but inconsistency in evaluating oncological results. Additionally, four studies focused on RP combined with androgen receptor pathway inhibitors (ARPIs) in the NHT setting, all showing primarily positive pathological outcome, with no clear evidence of an oncological benefit. Limited long-term follow-up data and a shortage of randomized controlled trials were evident among all the studies included in this review, regardless of the type of hormonal treatment used.

CONCLUSIONS

Different hormonal treatments, including traditional ADT and ARPIs, yield positive pathology outcomes. Oncological evidence remains limited, echoing older findings predating ARPIs. Definitive conclusions require longer follow-ups and precise patient selection. Currently, insufficient evidence support ARPIs' superiority over conventional therapy before RP.

Co-Inhibition of Androgen Receptor and PARP as a Novel Treatment Paradigm in Prostate Cancer-Where Are We Now?

Metastatic prostate cancer remains lethal with a 5-year survival rate of about 30%, indicating the need for better treatment options. Novel antiandrogens (NAA)-enzalutamide and abiraterone-have been the mainstay of treatment for advanced disease since 2011. In patients who progress on the first NAA, responses to the second NAA are infrequent (25-30%) and short-lasting (median PFS ~3 months). With the growing adoption of NAA therapy in pre-metastatic castration-resistant settings, finding better treatment options for first-line mCRPC has become an urgent clinical need. The regulatory approval of two PARP inhibitors in 2020-rucaparib and olaparib-has provided the first targeted therapy option for patients harboring defects in selected DNA damage response and repair (DDR) pathway genes. However, a growing body of preclinical and clinical data shows that co-inhibition of AR and PARP induces synthetic lethality and could be a promising therapy for patients without any DDR alterations. In this review article, we will investigate the limitations of NAA monotherapy, the mechanistic rationale for synthetic lethality induced by co-inhibition of AR and PARP, the clinical data that have led to the global development of a number of these AR and PARP combination therapies, and how this may impact patient care in the next 2-10 years.

Androgen receptor co-regulation in prostate cancer

Prostate cancer (PCa) progression relies on androgen receptor (AR) action. Preventing AR's ligand-activation is the frontline treatment for metastatic PCa. Androgen deprivation therapy (ADT) that inhibits AR ligand-binding initially induces remission but eventually fails, mainly because of adaptive PCa responses that restore AR action. The vast majority of castration-resistant PCa (CRPC) continues to rely on AR activity. Novel therapeutic strategies are being explored that involve targeting other critical AR domains such as those that mediate its constitutively active transactivation function, its DNA binding ability, or its interaction with co-operating transcriptional regulators. Considerable molecular and clinical variability has been found in AR's interaction with its ligands, DNA binding motifs, and its associated coregulators and transcription factors. Here, we review evidence that each of these levels of AR regulation can individually and differentially impact transcription by AR. In addition, we examine emerging insights suggesting that each can also impact the other, and that all three may collaborate to induce gene-specific AR target gene expression, likely via AR allosteric effects. For the purpose of this review, we refer to the modulating influence of these differential and/or interdependent contributions of ligands, cognate DNA-binding motifs and critical regulatory protein interactions on AR's transcriptional output, which may influence the efficiency of the novel PCa therapeutic approaches under consideration, as co-regulation of AR activity.

Short-term benefit of neoadjuvant hormone therapy in patients with localized high-risk or limited progressive prostate cancer

Purpose: Radical surgery is the preferred method for local high-risk and limited progressive prostate cancer in the routine clinical setting. However, current guidelines do not recommend neoadjuvant hormone therapy (NHT). Opinions regarding NHT vary among individual clinicians. According to the experience gained at our center, we explored the benefits of NHT for patients with prostate cancer during the perioperative period in this study. Methods: In this retrospective study, we explored the perioperative benefits of NHT among 189 patients with local high-risk or limited progressive prostate cancer who underwent radical prostatectomy and divided them into two groups: the NHT group and the non-NHT group. The NHT regimens were a gonadotropin-releasing hormone (GnRH) agonist alone (3.75/11.25 mg of leuprolide or 3.6/10.8 mg of goserelin acetate), an androgen receptor antagonist (ARA) alone, or a combination of the two. The duration of treatment was <3 months, 3 to 6 months, or >6 months. Results: We found that NHT could reduce the surgery time and intraoperative hemorrhage, thus reducing the difficulty of surgery; NHT could also improve the postoperative recovery of patients. However, it did not reduce the stage of prostate cancer or positive surgical margin rate. Conclusions: Neoadjuvant therapy is optional for some patients. We believe that NHT will improve the overall prognosis of patients as progress continues in the medical field in the future.