Patients’ preference and time to finish injection for GnRH agonist and GnRH antagonist in Japanese prostate cancer patients

ABSTRACT Huggins et al. introduced surgical castration for prostate cancer treatment in 1941. Currently, androgen deprivation therapy (ADT) is key in treating advanced prostate cancer, especially in elderly patients. With the development of gonadotropin-releasing hormone (GnRH) medications, ADT transitioned from surgical to medical castration. From 1985 onwards, various GnRH agonists like Leuprorelin and Goserelin acetate have been used as ADT for prostate cancer. By 2012, a GnRH antagonist, degarelix, was introduced in Japan. A study at Yokohama City University Medical Center analyzed 851 hormonal injections between August 2018 and February 2019. It assessed the duration from prescription to injection completion and the perceived physical and mental load on patients. Results showed degarelix injections took significantly longer than other treatments. Leuprorelin 22.5mg reduced hospital stays the most, largely due to its 6-month duration and kit formulation. The lengthy process for degarelix, which requires drug dilution and cooling at the injection site due to potential skin reactions, increases its administration time. Concerning patient burden, leuprorelin 22.5mg ranked the lowest, with little variance from the oral form. A limitation of this study is the administration method of leuprorelin in Japan, which differs from other countries. In summary, the 6-month leuprorelin 22.5mg regimen minimizes hospital time, while degarelix tends to cause the most discomfort for patients.