Gonadotropin?releasing hormone agonists in prostate cancer: A comparative review of efficacy and safety

ABSTRACT

Androgen deprivation therapy (ADT) using gonadotropin?releasing hormone agonist (s) (GnRH?A) remains the backbone of advanced prostate cancer treatment. In this review, we assessed the efficacy, safety, and convenience of administration of various GnRH?A. All GnRH?A (goserelin, triptorelin, buserelin, histrelin, and leuprorelin) have comparable potential to suppress testosterone (T) levels (?50 ng/dL in a month and ?20 ng/dL in 3 months). However, goserelin has shown better efficacy in maintaining T levels ?50 ng/dL compared with leuprolide. The incidences of T escape are lower with goserelin and leuprolide than buserelin. Goserelin also has maximum benefit in prostate?specific antigen suppression. In neoadjuvant setting, when only goserelin was used, the 10?year overall survival (OS) rate was 42.6% to 86%. When either goserelin or leuprolide was used, the 10?year OS rate was 62%. As an adjuvant to radical prostatectomy, goserelin had a 10?year survival rate of 87%, and triptorelin had an 8?year survival rate of 84.6%. Goserelin further showed an absolute survival rate of 49% when used as an adjuvant to radiotherapy. The survival rates further improved when GnRH?A are used as combined androgen blockade compared with monotherapy. The frequency and severity of adverse events (hot flushes, fatigue, sexual dysfunction) are comparable among the GnRH?A. Goserelin appears to be the most convenient of all the GnRH?A for administration. Lack of conclusive comparative evidence makes it imperative to have a holistic approach of considering the patient profile and the disease characteristics to select the appropriate GnRH?A for ADT in prostate cancer.