Should We Try Antiandrogen Withdrawal in Castration-Resistant Prostate Cancer Patients? Insights From a Retrospective Study.

BACKGROUND - It remains uncertain whether those with response to antiandrogen withdrawal (AAW) have a better prognosis. We investigated the predictors of a better response to AAW and overall survival after acquiring resistance to first-line androgen deprivation therapy inpatients with castration-resistant prostate cancer (CRPC).

PATIENT AND METHODS - We retrospectively reviewed the medical records of 87 CRPC patients treated at Keio University Hospital. Sixty-seven of 87 CRPC patients underwent AAW. We analyzed clinicopathologic parameters to identify predictors of survival in CRPC patients and investigated predictors of good response to AAW.

RESULTS - Younger age, longer duration of androgen deprivation therapy before CRPC development, and better response to AAW were independent favorable prognostic factors for overall survival. Although better response to AAW was a favorable prognostic factor in this study, trying AAW was not significantly related to overall survival. Duration of hormone therapy was significantly longer in those whose disease responded to AAW (69.9 ± 11.0 months) than those with no response (45.3 ± 5.2 months).

CONCLUSIONS - The prognostic benefit of AAW was not clearly determined in this study. However, AAW might be beneficial in patients who have favorable prognostic factors for a response to AAW-that is, those who have received hormone therapy for a long period. However, AAW should not be done in patients who do not have favorable factors and who had a high prostate-specific antigen level at the time of their prostate cancer diagnosis.

Clinical genitourinary cancer. 2016 Feb 23 [Epub ahead of print]

Hiroshi Hongo, Takeo Kosaka, Ryuichi Mizuno, Taisuke Ezaki, Kazuhiro Matsumoto, Shinya Morita, Kazunobu Shinoda, Toshiaki Shinojima, Eiji Kikuchi, Akira Miyajima, Mototsugu Oya

Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan. Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan., Keio University School of Medicine, Shinjuku-ku, Japan.