My grandfather was born in the 1890's in what was then called Indian Territory (aka Oklahoma). He refused to go to the doctor for his entire life. He had a heart attack at ~70 and died a week later in the hospital. No procedures, drugs, waiting rooms, or paper work. I really admire that approach.
Your story could be helpful to others. According to the doctors:
1) What is the years survived estimate of this vs doing nothing in your fathers situation (age, stage, etc)?
2) What are the side effects (and in general the quality of life) after/during this treatment vs doing nothing?
Also, these should both be some sort of histograms or at least ranges.