Your explanation was awesome as I m on ADT for 18 months now.

to reinforce what @web265 says

ADT doesn't kill prostate cancer cells, but it can weaken them and slow their growth.
ADT works by blocking androgens, male hormones that prostate cancer cells need to grow and spread. This can put the cancer cells into a dormant state, making radiation therapy more effective.

ADT is often used in combination with radiation therapy for locally advanced prostate cancer.

However, ADT is rarely curative, and some prostate cancer cells can develop the ability to grow in the low-testosterone environment created by hormone therapy. This state is called castration-resistant prostate cancer (CRPC), and hormone therapies have less and less effect on tumor growth over time. Recent clinical trials have shown that combining ADT with other agents, such as docetaxel and abiraterone, can lead to improved survival

There is frequently no "best" decision. In treating cancer there are trade-offs between present discomfort, the projected course of the untreated disease, and for every proposed treatment: duration of treatment, possible outcomes, expected outcome, immediate side effects, and long term side effects (e.g. cognitive difficulties, lymphedema, heart disease, peripheral neuropathy, secondary malignancies, etc.) Learn all you can about these many factors and then make a "good" decision.

Why combination therapy - heterogeneity and evolvability, via genetic or nongenetic mechanisms, are two of the greatest obstacles to the successful treatment of cancers.

This was my understanding as well. Which begs the question, why stay on ADT for 19 months post radiation? I could understand an additional 4-6 months, allowing time for the radiation to complete its task. Staying on ADT more than that seems like it’s either useless, because you’re already cured, or simply postponing the inevitable recurrence while possible making your cancer hormone resistant.

You are not an idiot. You are actually spot on with your explanation. ADT and ARSI's do not necessarily kill cancer cells. It shuts off the production of testosterone, the cancer cell need to use to survive. It starves the prostate cancer cells. Radiation and Chemotherapy are the only two treatments that are given at initial diagnosis that actually kills the cancer cells and unfortunately healthy cells. Radiation damage the cancer cells DNA which prohibits the cell from replicating and the cells die off. Chemotherapy kills all fast growing cells in your body. This is why I wanted to carpet bomb the cancer with radiation first followed by 10 cycles of chemo. Kill Kill Kill. That is the name of the game. Kill as many cancer cells up front s you can and do not leave any cells with possible mutations that can come back and get you.

I have a friend who has had metastatic prostate cancer for 8+ years. His cancer spread to his lymph nodes. His PSA was initially 1400 when the cancer was discovered. At the time, doublet therapy was the new standard of treatment. Back then, men were treated with ADT followed by chemotherapy. Once, the cancer became resistant, the doctor's started using ARSI's, such Apalutamide and later Xdandi. He because castrate resistant after 1 year and after trying Casodex again which worked for a period of time, he was later placed on Xdandi, which worked for years. His PSA recently started to rise again and he had a PSMA pet scan that showed the cancer advancing in a few spots. He is now getting radiation to those areas to kill the cancer. Pulling us back into our discussion, radiation , targeted radiation is used to kill prostate cancer cells directly. I' confident that the direct radiation shall kill the resistant cancer cells and his PSA will become undetachable again with the cancer under control. This is also a good example of how this disease is fought and won over longer periods of time. Hope! Faith! Strength! Good Attitude! Exercise! Eat healthy 70% plant based diet! It all helps and makes a difference.

Actually, no testosterone has nothing to do with PC. Androgen Deprivation Therapy (adt) is what lowers psa and maybe kills PC. My T levels rose to 1000, while doing adt and psa drops. Androgen is not the same as Testosterone.