I had prostate cancer at64 The worst of the experience was Lupron, do a search on the internet Lupron ruined my life . After treatment I was weak all the time and had a hard time walking, no sexual feelings and mental confusion. After researching these symptoms I had a testorone test by another doctor and found that it was 53.
I began Testorone replacement therapy which was an IM shot every two weeks that I gave myself.
My PSA briefly came up to .2 but returned to .1 after three months.
I began the carnivore diet and lost 46 pounds and exercise every day.
The one thing I discovered is my doctor was wrong about everything and working with data 20 years old.
I think your friend can make a full recovery but it is hard work and he needs to see a competent Dr.

My ED is gone and I sometimes wake up excited. I will stop taking testorone next month and see what the blood work looks like.