Hormone Treatment

Yes, hormone therapy will pause the cancer for a while. Hormone therapy by itself is not curative though, and eventually it stops working. During COVID in particular, it was used if curative treatment was significantly delayed, including prostatectomies.

Hormone therapy is also included as part of many (but not all) radiotherapy treatments, and that's for a different reason. Hormone therapy makes radiotherapy more effective, in some cases doubling the cure rate of the radiotherapy. In this case, you have hormone therapy for 3-6 months before the radiotherapy, and you continue the hormone therapy afterwards for up to 3 years in total (depending how high a risk your diagnosis was). For some types of radiotherapy and lower grade disease, hormone therapy is not so beneficial and might not be offered.

Hormone therapy is also used to shrink large prostates before radiotherapy. In this case, it's used for 3-6 months beforehand, but is stopped after the radiotherapy.

Thanks, I knew most of this but what I am not sure about and I apologize for not making this clear is the following. I am attempting to get my PSA down to a level before radiation commences. Now three months in and before I know it six months will have elapsed. My actual question is, for how long can I keep trying to bring it down before a decision needs to be made to commence radiotherapy. I assumed that my PSA would fall quickly and that my radiation would be planned for May/June. I am now worried that on my case the PSA may not fall to the desired level. Hypothetically speaking could I continue with HT and no RT for longer than six months? 

I did the same. I was going to be booked for RT at 3 months, but I delayed it a couple more months to get my PSA lower. My oncologist was fine with me delaying the RT, but said I should only delay while PSA is dropping at a significant rate (which it was), and not any longer than 6 months. He'd had other patients do this, and had one patient where the PSA had started rising again before it got down to his target as he was becoming castrate resistant, and he was likely reducing his chances of a cure by delaying RT that far (although there's no research on that). Some peoples' PSA just won't go ultra low on HT.

This is a discussion to have with your oncologist. I was lucky mine was open to me influencing my treatment in such a way.

Hello Andy and RENs, please forgive me if this is a silly question about HT!

if HT cannot cure prostate cancer and only stops the cells from proliferating, does this mean that any cancer cells not killed by RT survive and will start to proliferate once hormone therapy stops?  That is, do the cells remaining after hormone therapy die off or do they remain in some sort of dormant state? If they do die off, how long does it take them to die?  What continues to puzzle me is the science ( rather than the statistics gained by watching recurrence rates etc)) underpinning the decisions made about the differing lengths of time men are recommended to continue on HT.

I asked the oncologist and his answer was, ‘ this is the million dollar question’. Really?

There are two questions there.

The first is about how RT works. RT does not instantly kill cancer cells, and that isn't what it's aiming to do. What it's aiming to do (and is remarkably successful in doing) is to damage the DNA in the cancer cells so badly that they cannot divide and form new cancer cells anymore. Some are killed outright (as are some non-cancer cells), but many cancer cells will continue living until they die of old age in 18-24 months. However, since the RT has stopped them from dividing, they are no longer malignant and can't grow any more tumors.

How does the HT help with the RT?
That's probably the million dollar question. There are probably two effects. The hormone therapy switches off the prostate cells and this also stops the prostate producing much in the way of new cells. Having them switched off during RT may be beneficial. We do know that many cancer treatments benefit from hitting the cells with multiple things at once. For any one treatment, let's say one in a million cells may survive. If you use two treatments at once, it will be a different one in a million cells which survives each, but only 1 in a billion which survives both, which very significantly multiplies up the effects of multiple treatments at once.

The second side of hormone therapy relates to the response of any mets to zapping the main tumor, something that has only relatively recently become known. It does seem that there's some signalling or support provided from the main tumor which encourages distant mets to grow, something which was discovered by treating the main tumor in men with small numbers of mets, which slowed down the growth of the mets when the main tumor was destroyed/removed. In the case of radiotherapy, recurrence tends to be because there were already some unknown mets elsewhere, often micro-mets which are too small to show on any scans. (Recurrence in the target radiotherapy area can happen, but is much rarer.) It seems likely that a combination of HT after the RT and the effect of losing the main tumor may be enough to kill off distant micro-mets too.

Whatever the mechanism is, we do know that having HT with some types of RT doubles the cure rate. HT is not risk-free itself, so it's not used in cases where the benefits are marginal or don't outweigh the risks.

Brilliant answer, Andy. Thank you so much !  I appreciate the time you have taken to respond to what has been puzzling me for some time.

Thanks both. I am convinced of the benefit of combined HT and RT in tackling locally advanced high grade cancer such as mine. Sadly HT has many side effects. 

However here is an interesting consideration. My oncologist mentioned that an MRI cannot determine T3a and that many T2b are in fact T3a and therefore advocated RT of the whole pelvic area. Now whilst this may be classified as belt and braces and I think you went for this Andy, additional radiation means additional risk; radiation is per se toxic. Now here is my question: " if HT also eliminates invisible micro-mets in the lymph nodes, why would one require additional RT?" Hope I made myself understood?

Rens

Another interesting comment and question, Rens. My husband was diagnosed as T3A because there was a possibility that the tumour making the prostate wall bulge might have spread into the nearby tissue. The oncologist told us that the decision is always made to treat as the highest grade level indicated - ie err on 'over treat' rather than 'under treat'. So the radiotherapy was targeted at the whole prostate and surrounding tissue. If I recall correctly, he said that the lymph nodes behind the prostate would also be targeted but not others in the wider pelvic area? 

Following Andy's reply, I also question why, if the cancer cells take 18-24 months to die of old age why is HT prescribed for 18 months - ie there may be some left that are still 'alive'? Is 24 months HT a safer 'bet' having got that far? I acknowledge the trade off between killing potential rogue cells and the side effects and complications of longer HT.

I think I've already passed my urology exams and am now embarking on the oncology ones!!!

Well Worriedwife, I am no expert and make no claims to be. First, I think that by it's very nature cancer is an uncontrolled and haphazard division of abnormal cells and as such is unpredictable. Second, although a lot is known a lot is still unknown and it is obvious that global treatments vary according to geography. From the little research that I have done it would seem that 24 to 36 months was standard across Europe and the UK but as radiation has improved significantly it seems that some now recommended 18 months. I have not encountered anything definitive but although my oncologist has said 24, I would be happier with 18 in the hope if retaining some of my manhood. No doubt Andy has a view :).

Rens

Rens 

I was diagnosed in 2018 as T3A N0 M0 with a PSA of 15 and a Gleason score of 4+5=9. The Oncology Consultant told me at the time that I would be on HT for 24 months but at a later appointment, following my RT, that was revised to 36 months as they said cancer was more aggressive than they first thought. In 2020, at the start of lockdown, we moved to a new NHS trust in a new area and there was a lot of confusion with medical records getting lost somewhere in the ether. Towards the end of 2020 I received a letter from the new oncology department saying that I should stop HT immediately (after only 24 months) as that was "their policy". I wasn't 100% happy with that idea and contacted my original oncology nurse who remembered me (as we had rowed in regattas together) and he said that, as long as I was tolerating the HT well enough, he would recommend the full 36 months as the PC was a Gleason 9. I went with that and stayed on the Prostap for another year until my last injection in June 2021.

It seems to have worked as my PSA has been stable at 0.2 for a year now having risen from <0.1 during HT. Of course I'm pensive prior to each six-monthly PSA test, but so far so good. If everything stays as it is, I will move on to annual PSA tests in about two years time.