My Mom had breast cancer when i was a kid. I know this story may sound unbelievable, but after that, i can say miracles exist.
The doctor only gave her six months of life, she already had chemotherapy, but one of her ganglions already ramified.
After hearing that, my Mom wanted to live with all her heart, because, while my Dad is a good man, he wasn`t the most responsible with kids, so she could not leave us in this world without making sure we would be okay.
So she prayed (She is a Catholic Christian), talking to God like someone talks to a father and she begged to him, she basically said "please, this is extremely easy for you, and i can`t leave yet". After that prayer, she felt a lot better and an incredible joy. She told the doctors she felt better. Obviously they did an exam (it would be irresponsible not to). They were shocked with the result, the cancer disapeared and the doctors could not explain how.
After that, my mom helped to found a corporation against breast cancer in our country. She no longer works there, because she had to get a job, but she still shares her experience with people who suffered the same as her.
I never thought i would share this story in the forums, but that hitted too close to home . (if that didn`t happened, i would probably be agnostic by now)
I can`t say miracles are common, but they exist. I dont know how religious your friend or his mom is, but i will pray for them anyway.
Also, if you, your friend or his Mother want advice from my Mom, i would gladly ask her. And she would be happy to help.
Dawg, I wish your friend and his Mom the best, and if you need anything (legal and ethical) you can count of me (virtual hug of emotional support)