A narrative review of the role of glucocorticoid receptors in prostate cancer: developments in last 5 years

Background and objective: Glucocorticoids, secreted from the adrenal gland, are commonly used in the treatment of castration-resistant prostate cancer (CRPC) because of their anti-inflammatory and anti-toxic effects. However, glucocorticoids have been reported to have the opposite effects within the course of treatment. Many studies have shown that glucocorticoid receptors (GRs) are involved in the establishment of a dominant population of androgen-independent malignant cells, which may result in CRPC. In this review, we summarized the mechanisms of GRs in CRPC and the clinical application of glucocorticoids based on the present evidence.

Methods: We summarized the isoforms of GRs and the mechanisms involved in CRPC. An updated literature search was performed from the ClinicalTrials database, the National Center for Biotechnology Information database and European Union Drug Regulating Authorities Clinical Trials database. The focus was on the timeframe from 2017 to 2022. At least one primary or secondary outcome [prostate-specific antigen (PSA) response rate, progression-free survival (PFS) or overall survival (OS) and median time to PSA progression] according to studies should be included.

Key content and findings: The molecular structures and applications of the isoforms of GR have been intensively researched in the past 60 years. In recent years, researchers have pointed out that GRs may be involved in the development of CRPC via genomic and non-genomic effects. Clinical trials in the past 5 years have focused on the efficacy of drugs regarding CRPC. The use of glucocorticoids during treatments of CRPC follows the guidelines (e.g., NCCN Guidelines^®, guidelines of CSCO, etc.). Based on the collected data, prednisone appears to be the most widely used steroid hormone, followed by dexamethasone. Comparisons of the PSA response rate and the median time to PSA progression revealed that the efficacy of the 2 hormones is similar; however, further research on the effect of steroid hormone in CRPC is still required.

Conclusions: Various GR isoforms may play an important part in the development of CRPC, whose mechanism remains unclear. Most clinical trials have focused on the use of prednisone in the last 5 years. The efficacy of prednisone and dexamethasone is similar.