Favourable response of serum prostate-specific antigen to conjugated oestrogen in castrate-resistant prostate cancer in Jamaica

Conjugated oestrogen is one of the more affordable secondary hormonal options available for castrate-resistant prostate cancer (CRPC) in Jamaica. The present study was conducted to examine the disease response in Jamaican men with CRPC treated with conjugated oestrogen. This study retrospectively reviewed the medical notes of patients who attended the urologic clinic of the University Hospital of the West Indies from 1 January 2009 to 31 December 2013 and a private urology clinic from 2 November 2005 to 3 June 2015 to identify patients diagnosed with CRPC treated with conjugated oestrogen (Premarin ®) as secondary therapy. The primary endpoint of favourable response, using the Prostate Cancer Clinical Trials Working Group 2 criteria is a decline of ≥50% in serum prostate-specific antigen (PSA) concentrations from baseline after treatment. The proportion of patients responding by the first 3-month follow-up visit and the maximal PSA declined over the 24 months of follow-up which were recorded. Thirty-two patients diagnosed with CRPC and treated with conjugated oestrogen were identified. All patients were prescribed 5.0 mg (2.5 mg tablets, twice daily) orally, as well as low dose aspirin. Favourable response was observed in 14 (43.8%) patients; however, eight other patients showed a decline in serum PSA concentration of <50%. There were no reported adverse effects. Conjugated oestrogen produced a PSA decline in Jamaican CRPC patients of this study and may therefore be a useful option for secondary therapy of CRPC. Further assessment is needed.