I wouldn’t recommend not going through treatment to anyone.
In fact, when I was in the chemo center on two different occasions two people I had arrested were seated right next to me.
I could have just sat silently because neither one recognized me because of my weight loss.
The first one pretended he didn’t remember me after I told him who I was but I encouraged him anyway to stay strong and he returned the same.
The second one about fell over when I told him who I was. He couldn’t believe I was there and going through treatment. He told me how sorry he was for me having cancer and I returned the same respect to him.
My son worked court security and many bad guys that knew me very well told my son they were praying for me to be ok.
So no matter who we are or what we’ve done cancer has no preference and people we never expected to care reach out.
I’m sure you have people in your life too that would say, stay strong and fight the good fight my friend!

MOJO

I was told I wouldn't likely meet anyone experiencing the same cancer as myself in my lifetime. I've since met half a dozen or more who were either going through it or one of their family members were, and one was my sister and another was my wife's uncle. Most underwent treatment right away. Some didn't make it the 5 years. One ignored the problem until it became too difficult to continue. They had to remove his tongue and lower jaw. Eventually, he succumbed, though I'm unaware if it was to cancer or illness. The earlier the intervention, the better your chances, so I would suggest you proceed without delay. I'm now 19 years out and have done a lot of living since my experience. There is life afterward, so live it.

Not treating the cancer is a personal decision only you can make. I only know of one person who, three years older than you, had hospice care and morphine or similar in the last few weeks.
A hospice nurse might be able to fill you in on how this would all go down.
We here on Connect try to encourage one another to fight and go on through recovery. As for me, if and when I am again faced with a reoccurrence, at my age, would I fight or not? I cannot say for certain either way.
As for you, I hope you give it a fight, best you can.