Does ADT actually kill cancer cells?

Perhaps it has more to do with terminology than disagreement. Each cubic centimetre of a cancer tumour contains roughly 1 billion cancer cells (that's a conventional working number; some researchers think it should be slightly lower). So if a few million cells die off here or there, it probably doesn't make enough difference for oncologists to say that ADT is "killing" cancer cells.

The real question is whether enough cells survive in hibernation (go dormant) to regrow the tumour later. Radiation, chemo, and similar attempt to target all the cancer cells, including the dormant ones.

(insert standard layperson caveat here)

I've had this as well...
"When I asked the question about hormones killing cancer cells, two replied no, they don't, and one confirmed hormones did kill prostate cancer cells. Okay, now what?"

My RO: "no, ADT doesn't kill the cells" Surgeon: "ADT kills the cells."
When you get conflicting answers like this, it wears heavily on your confidence in your team.
..and this pair is from the same group...

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.

Some great comments to a vexing question.

I was told I am not a candidate for proton therapy due to the volume and location of cancer cells in my prostate and pelvic region. So instead of Eligard plus proton as the initial course of treatment, it is Eligard plus Erleada for several months in hope they will reduce the volume and edges sufficiently for proton to be viable.

If hormone therapy does not kill the cancerous kills how is the volume reduced? By ablation from the shear on their surface from the circulating blood flow? Chunks of dormant cancer cells get "ripped off" from the tumor? So the volume of the tumors are reduced but the now circulating cancerous cells either cannot adhere elsewhere or it they do it is not a big deal since they are not growing/growing very slowly?

Med science sure ain't physics.

This is the heart of the matter for me. I had three months of Eligard then 33 fractions of IMRT. After 6 months of Eligard i insisted on switching to Orgovyx and they added in Abiraterone. I have now been on that combination 2 months and am 2.5 months post radiation. My PSA is now 0.02. The MO wants me on the ADT for at least 11 more months and preferably 17 more months. But in my mind I’m either cured already and am suffering the ADT side effects for nothing, or I’m not cured so let’s stop, see where the cancer is and then move on to chemo or targeted radiation.

@rick137
same thought here, same question marks

ddl,
Hoping we're right. Best wishes

Disclaimer: I am not in the medical field but talk frequently with a lifelong friend who is a retired MO and, like others here, have read a lot of reporting on trials and other medical literature on PCa.

I think a key point that is being missed is that the body's immune system has the innate ability to kill cancer cells. However a point is reached when the number of cells is too large and the rate of replication too fast for it to keep up. That is why it is important to detect and treat it as early as possible and to apply therapies that may be synergistic in their effects.

Therapies that suppress testosterone production and those that interfere with its ability to support cell division help suppress or halt the rate of growth (aka cytostatic mechanisms) so that cytotoxic biochemical radiation processes will have an easier task to kill all or more of it. I suspect when people say that ADT kills cancer cells, they mean ADT in conjunction with the body's immune system.

According to this government publication abiraterone does is successful in killing some prostate cancer cells.
https://pubmed.ncbi.nlm.nih.gov/36413141/#:~:text=Plk1%20Inhibitors%20and%20Abiraterone%20Synergistically,Independently%20of%20Androgen%20Receptor%20Signaling