Bipolar androgen therapy (BAT) in men with hormone sensitive (HS) prostate cancer (PC).

236 Background: We documented a paradoxical anti-tumor effect when castration-resistant prostate cancer patients were treated with intermittent, high-dose testosterone (i.e. BAT) [PMID: 25568070]. Since the adaptive increase in androgen receptor expression that follows chronic androgen deprivation therapy (ADT) may underlie this effect, we tested whether men with HS PC would also respond to BAT if given following a 6-month ADT lead-in. Methods: Men with asymptomatic HS PC and low metastatic burden (N = 20) (no visceral disease, ≤ 10 bone metastases, no lymph nodes > 5 cm short axis diameter) or non-metastatic biochemically recurrent disease (N = 13) were enrolled. Following 6-months of ADT, those with a PSA < 4 ng/ml went on to receive 2 cycles of BAT. A cycle of BAT was defined as intramuscular testosterone (T) cypionate or enanthate 400 mg on Days (D) 1, 29 and 57 followed by ADT alone D 85-169. ADT was continued throughout the study to allow for rapid cycling from near castrate to supraphysiologic rang...