Yes, I have known someone in their 20’s that has gone through chemotherapy but I am not sure why you asked that question as I fail to see the relevance. My dear friend lost their life even, but I am not sure how my knowing someone that was sick has any bearing on my telling someone here that artificial insemination is immoral.
You asked why I would suggest that course of action. I suggest it because I have seen firsthand what a 20-something in chemo goes through, and it would take a huge load off of his mind and heart.
Blue Eyed Lady you are on a Catholic website encouraging someone to bank sperm so they can possibly potentially artificially inseminate their future wife. Even though they might not go through with it you believe just knowing they could possibly inseminate their wife will bring them a sense of peace, and they can just put it aside and deal with it later. It doesn’t work that way, maybe in your believe system you think it does, but you are participating in a Christian discussion forum. We are not to draw peace from these kinds of actions because Christ teaches they don’t bring peace.
Well, if the sperm banking can be done without masturbation there is no sin.
I feel very sad for the original poster and have been praying for him. While I did not want to seem cruel to someone facing a life and death crisis I did not want to lie to him either. He came here seeking the truth and I am sure the truth was very painful for him I can only imagine how hard it is to hear it I am very sad for him. To want children is only natural for someone so young, naturally he is hoping for a miracle, but to encourage him in some sort of “loophole” to circumvent Catholic church teaching in the false hope he can bank sperm and save them for legitimate use later is misleading and not fair to him.
You won’t agree with me I can imagine but I believe in this serious kind of life decision he deserves to know the truth not just opinions based on emotions.

I’m sorry that you feel that I’m encouraging him to sin. I do not view it that way and it is not my intention. I am encouraging neither masturbation nor artificial insemination, just a psychological trick to help ease at least some of the stress and worry of a young person going through something that he should never have to.