Impact of surgical and medical castration on serum testosterone level in prostate cancer patients

Introduction: The paper aims at evaluating the role of testosterone levels and their cut-off points in the treatment of prostate cancer with androgen deprivation therapy. Materials and Methods: We performed a non-systematic review of the literature, searching Medline using the following key words: ‘Prostatic neoplasms/therapy’ [MeSH], ‘Buserelin’ [MeSH], ‘Goserelin’ [MeSH], ‘Leuprolide’ [MeSH], ‘Triptorelin’ [MeSH], ‘prostate cancer*’ [tiab], and ‘testoster*’ [tiab]. Results: The most commonly used cut-off point of testosterone to define castration was 50 ng/dl. In this respect, GnRH agonists allowed castration in a very high percentage of patients (87.5–100%). Specifically, triptorelin was reported to yield castration level of testosterone in 98.8%, the classical formulation of leuprolide in 95–98.8% of the cases, and Eligard®, a novel formulation of leuprolide, in 99–100%. With regard to the 20-ng/dl breakpoint, available data suggest that goserelin yields castration level of testosterone in 96%, the classical formulation of leuprolide in 87–92% of the patients, and the novel formulation in 88–97.5%. Conclusions: The clinical significance of different levels of testosterone yielded during androgen deprivation therapy is still unknown. Considering the standard cut-off point of 50 ng/dl, GnRH agonists allowed castration in a very high percentage of patients.