How long can PC cells survive without testosterone?

One would think that after all these years we would have some sort of time table discovered on the how long PC cells can survive without T.
I'm sure it depends on whether or not the mutated cells are confined to the Prostate.

Prostate cancer cells need testosterone and other male hormones to grow. These hormones act like a fuel to feed the cancer cells and keep them active.
Hormone therapy works by lowering the testosterone being made in your body. When the testosterone is taken away from the cancer cells, they will either die or
slow down and stop growing.

Your question has several answers. Prostate cells, benign and malignant, depend on androgens, testosterone being the most common of them. There are other hormones in the body which can provide the necessary component for cellular division in the absence, or nearly so, of T. Even beyond that it has been discovered that the PCa cells can produce a kind of androgen themselves, intracellularly. This is most likely from conversion of cholesterol which is very close to T (and estrogen) at a molecular level.
The question of how long a cell or cells may be dormant before regenerating to an extent that produces measurable psa has no real answer. Or the answer is "As long as it takes". Men who are considered "cured" have cancer cells in their body, as is also true of cancers of other origin, and it is because the cells are too few and are in a location infertile, so to speak, to their rapid regeneration. This can all change if the immune system is weakened, cells adapt to a more vigorous clone, or some unknown reason.
If men lived an indefinite time then it is quite possible that recurrence would happen with everyone. Fortunately neither of these things is true.