Hi Gerry2
It is a very personal decision, that only you can make - And very brave if you choose not to have treatment. xx
Having said that - with the huge advances in medical treatment in recent years (think of Professor Richard Scolyer who is pioneering new treatment tested on himself) is still getting out there, living as full a life as he can.
There are many new treatments - and with DNA analysis it can be tailored to your specific genome ...
Don't write yourself off yet .... one of my friends who was diagnosed straight up with stage 4 Prostate Cancer (at the same time I received my own 'lesser' diagnosis 8 years ago when I was 64) ... is a few years older than me, so would be mid 70s now - his passion is offshore kayak fishing, for the BIG Pelagics!
He is still getting out offshore on his kayak, catching marlin, cobia and yes, even sharks .... and has even caught 5 marlin (all released) in the one day!!
Admittedly, he is slowing up a bit now but so am I! (His slowing down is as much from age as anything) .... So he is & has been "still him" for the last 8 years & will continue to be 'out there' for as long as he can - he still has enough energy to do other things he wants to do - and still loves his life.
Remember - not everyone gets side effects ....
Keep chatting with your Onc.
All the best xx