I find this the troubling aspect of our disease. Other cancers are also very adept at surprisingly rapid response evolution to treatments. My late niece had appendix cancer that was first in the form of several very large (grapefruit, orange and lemon size) solid tumors. After removal and chemo, they returned as thousands of poppyseed size growths throught her abdomen. More surgery and different chemo. Then a few months later it returned as a malignant mucous form throughout her system and nothing helped. All this in about
eighteen months.
Regarding PCa, a former client was treated for about seven years that eventually ended up being small cell tumors in his lungs. He had several experimental drugs he paid for that were in trials as well as all the surgery, radiation, ADT, and Taxotere. My med onc was treating him and said it was his toughest case ever and they threw everything they had against it. But it just kept coming back and eventually in a completely different form.