Steroid switch after progression on abiraterone plus prednisone in patients with metastatic castration-resistant prostate cancer: A systematic review.

BACKGROUND: Emerging evidence indicates that patients with metastatic castration-resistant prostate cancer could respond to steroid switch from prednisone (P) to dexamethasone (D) following progression on abiraterone acetate plus prednisone (AA+P).

OBJECTIVES: Conducting a systematic review to evaluate the efficacy, safety, and prognostic factors of steroid switch.

MATERIALS AND METHODS: We systematically searched Pubmed, Web of Science, and American Society of Clinical Oncology annual meeting abstracts published up to October 2020. Literature review, study selection, and data extraction were conducted by two reviewers. Risk of bias (RoB) and quality of evidence were assessed. A systematic review and pooled analysis were performed.

RESULTS: Nine studies were eligible for inclusion. All of the included patients were progression on AA+P. Pooled rates of PSA50 and PSA30 on abiraterone acetate plus dexamethasone (AA+D) were 0.24 (95%CI [0.18,0.30]) and 0.42 (95%CI [0.36,0.48]), respectively. Subgroup analysis indicated more favorable PSA50 and PSA30 rates on AA+D when switching from P to D only based on PSA progression. Median time to PSA progression on AA+D ranged from 2.73 to 11.38 months. Definitions of progression free survival were variable. Reported median progression free survival on AA+D ranged from 2.52 to 11.8 months. Median overall survival on AA+D varied from 4.11 to 20.9 months. All patients tolerated well on AA+D, and no grade 3 to 4 adverse events were reported. Baseline characteristics of patients, previous treatment and its response, and genetic alterations might all play roles in the response in the response toward the AA+D regimen.

CONCLUSIONS: The present systematic review suggested that steroid switch from P to D might be an effective and safe treatment strategy in a subset of patients with metastatic castration-resistant prostate cancer after PSA progression on AA+P.