When it comes to Prostate Cancer Diagnosis and treatment, the NHS usually provides a priority service where you can at least start your Cancer Journey. Mostly, you will be treated by the same practitioners that treat privately using similar or identical treatment/equipment. Also, NHS treatment can open the way to trials where you get extra attention. This can be important where you pose a difficult case. There are many good UK Hospitals but I think it can be worth the extra effort and or travel to be seen/treated in one of the leading hospitals in London or well regarded hospitals in major towns. (When I moved from Greater London to Devon, UCLH wanted my care to be transferred to a local Hospital but I rejected this. Had I agreed I would not have had a second HIFU but just been on Hormone Therapy with attendant side effects. The second HIFU with no HT resulted in my being told I am in remission.)
I had my initial advanced RT done in Germany within a trial but returned to the Royal Marsden to be monitored and it was they who referred me to UCLH for HIFU within a trial at no cost UCLH still monitor me and I have just had an MRI check up, now done every second year wihin the NHS.
As regards a long wait for knee surgery, this can take so long I might be tempted to go private to get this done earlier.
Similarly, I had been waiting Cateract Surgery on the NHS for over two years and decided to have this done privately. I also had this combined with a procedure for Glaucoma called MIGS. A small titanium stent is put in the eye which relieves the pressure on the Optic Nerve. It was quite a chunk of cash but was done by a top surgeon. The MIGS procedure is only recently started being done on the NHS in a few places. The surgeon implied the Cateract in my left eye had been left for too long and the operation was "a little tricky". Anyway, everything is so much brighter now and although I need glasses just for reading, my eyesight is now 20/20 and pressure on the Optic Nerve most satisfactorily reduced. What price your eyesight?!! Incidentally, my surgeon wrote to my GP asking if he would get me referred back to the hospital in Devon for monitoring as I am 200+ miles from where I had the surgery and this has been agreed and appointment made.
I think for Prostate Cancer it makes sense to get this sorted on the NHS in most cases and if you don't have medical insurance, put something aside if you can for procedures like I have mentioned that are not as well covered in terms of time or type by the NHS.