What is the mechanism of action for leuprolide in treating prostate cancer?

Leuprolide is a synthetic analog of gonadotropin-releasing hormone (GnRH) that functions through a specific mechanism of action in the context of treating hormone-sensitive cancers such as prostate cancer. When administered in a continuous fashion, leuprolide initially stimulates the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which subsequently leads to an increase in testosterone production by the testes. However, prolonged exposure to leuprolide results in downregulation of GnRH receptors in the pituitary, ultimately leading to decreased release of LH and FSH. This in turn reduces the stimulation of the testes, leading to a decrease in testosterone production.

This decline in testosterone is critical for managing advanced prostate cancer, as testosterone acts as a growth factor for prostate cancer cells. By decreasing the levels of LH and consequently testosterone, leuprolide creates an environment where the cancer cells are less activated and have a reduced capacity to proliferate.

This mechanism emphasizes the importance of hormone regulation in cancer therapy, particularly in hormone-responsive tumors. The reduction in testosterone levels, achieved through the use of leuprolide, is vital for slowing disease progression and can ultimately lead to improvements in patient outcomes.