Definition of hormone resistant pca?

I'm a bit confused about the definition of hrpca.
I though that hrpca means that the cancer grows despite blockade of androgens? (low testosterone levels).

But why do they say that the cancer is resistant to hormone therapy when it becomes hormone resistant? When they say that, it sounds like the medicine doesn't work anymore (that it's not able to keep the testosterone levels low). If so, the testosterone levels would increase and feed the cancer. But that is not the case, is it? If so, wouldn't it help to switch to a different medicine that is more effective to lower the testosterone levels?

They don't like to use the term "hormone resistant" anymore. Instead, they prefer the term "castration resistant" or CRPC. This reflects the fact that the cancer continues to grow in spite of chemical (e.g., Lupron, Firmagon) or physical castration cutting off the testicular supply of testosterone. It has been recognized that it is important to continue choking off that supply even though CRPC has set in because the tumor becomes exquisitely sensitive to even the tiniest amounts of androgen. In addition, second-line hormonal agents are brought in to help prevent other sources of androgens (e.g., adrenal, intratumoral) and to block the tumor from activation by androgens and similar molecules.

- Allen