Introduction
Androgen deprivation therapy (ADT) is a standard of care for metastatic
prostate cancer (PCa), however, eventually, all men relapse. Docetaxel
has long been the only agent demonstrated to improve overall survival in
castration-resistant prostate cancer (CRPC) patients(9). New androgen
receptor-axis-targeted agents (ARAT) have improved the prognosis of men
with CRPC patients. Although ARAT improves survival in CRPC PCa
patients(6), they remain incurable and eventually progress. A new
approach to hormonal therapy is necessary. It has been reported that the
growth of some PCa cells can be inhibited by supraphysiologic levels of
androgens(2). High doses of testosterone (T) are administered monthly
and the supraphysiologic T level is followed by a rapid drop to
castration levels during each cycle of therapy(2). This was called
”bipolar androgen therapy” (BAT). Although the mechanisms of BAT are
currently poorly understood, clinical responses have now been observed
in men with PCa treated with high doses of T. Although several clinical
trials using BAT have been reported (3, 4), its application for CRPC is
still controversial. We report on 4 heavily pretreated CRPC patients
successfully treated with supra-physiological doses of T.