Active surveillance with cribiforms

There are no medics here. The only support group I know of which always has consultants available is The FOPS, which currently meets monthly alternating between in-person at Chorleywood (near M25 J18) or on Zoom. Some other local support groups will occasionally have a guest consultant or CNS.

I agree with Dave (except I'm not sure there's a distinction with invasive and non-invasive cribriform).

Cribriform is associated with a higher chance of distant mets, and that's not really consistent with Active Surveillance as there's a higher risk of it going metastatic without first observing more changes in the prostate.

For a prostatectomy, you should certainly ask about your chances of nerve sparing if that's important to you which you have done - this will depend where the cancer is inside the prostate. However, even with nerve sparing, erections don't always recover, and when they do, they usually aren't as good as they were before, although they can still be good enough and things like Viagra/Cialis can help in this case.

It is often suggested that radiotherapy is likely to cause less damage to erections and urinary continence, but although it may be lower risk, that's not risk-free either. Unlike prostatectomy, damage due to radiotherapy is not usually immediate, but if it's going to happen, it tends to start within 2 years and get gradually worse. Radiotherapy does have a higher chance of causing bowel problems, although serious problems are quite rare with modern radiotherapy targeting accuracy. Radiotherapy usually comes with temporary hormone therapy, and you do have to undertake penile physio while on hormone therapy to protect the tissues of the penis so that doesn't damage them.

Unfortunately, no treatment is risk-free, and neither is Active Surveillance. It is a challenge weighing up treatments which are all likely to give you some side effects when you have no sense you have anything wrong with you.

In any support group, you probably get a worse impression than is the reality, because most of those who don't need any more support after treatment don't stay, whereas those with problems are more likely to stay.

I went for radiotherapy because surgery was unlikely to be nerve sparing in my case, and it was thought quite likely I'd need radiotherapy afterwards in any case, so why not skip the surgery and side effects it might bring, and just go for radiotherapy? Some 4 years after making my choice and 3½ years after the radiotherapy, I'm lucky and everything still works exactly as it did beforehand, which is not at all what I was imagining would be the case when I was at your stage. There are no guarantees of this of course. I do have a long term side effect which is minor painless rectal bleeding, but it doesn't impact my quality of life in any way.

My cancer was throughout my prostate it certainly ruled out focal treatment, but RT is generally not considered a focal treatment in fact sometimes the beam is deliberately widened to include more of the pelvis in the hope of picking up any stray cells.

We have to assume the oncologist is right in advocating RP over RT, but the onco will be balancing the pro and cons against how well they think an average person can handle the side effects as opposed to how well YOU can handle the side effects.

For the sake of argument let's say that RP has a 70% chance of curing you but RT only a 60% chance. Then clearly it seems best to steer you to RP. However if RP has a 40% chance of leaving you with ED but RT only has a 30% chance of leaving you with ED, then if you value your erections more than your life RT is the best option.

Of course the above percentages are just examples we don't know the real percentages and we don't know all the possible side effects of each treatment. Only you know how important you rate quality of life over quantity of life.

Most newly diagnosed people are so fearful of death that they want the most aggressive treatment whatever the consequences, it is only when they are "cured" and have a clear head that they realise what they have lost and perhaps a less aggressive treatment would have been better. 

If you know anything about "survivor bias" you will realise the above argument, has the problem that those who chose the least aggressive treatment are probably dead and don't have the luxury of complaining about ED.

The good news is you are thinking with a clearer head than most people in your position absolutely no one will be able to give you precise percentages for cure and side effects, and even knowing 70% cure rate has no real use to you, because you will either be 100% dead or 100% alive. At least you can now have a more informed discussion with the oncologist and see if your preferences are enough to justify a change in treatment plan.