Castration is a prerequisite for the inhibitory effect of metronomic chemotherapy on the growth of experimental castration-resistant prostate cancer.

This study shows that a low-dose metronomic scheduling of CPA was as efficient as MTD treatment, and resulted in fewer side effects. It also demonstrates that a functional androgen signaling axis inhibits this effect despite the castration-resistance of the tumor cells. The anti-angiogenic nature of the effect of LDMC could not be confirmed and further studies to elucidate the working mechanism for treatment response are needed.