Sometimes when a person feels they are nearing the end of their life, they decide they want to be left alone to deal with it. It's not that they don't want to see you, or be around you, but they are dealing with something a lot bigger than relationships.
Your friend has a right to be left alone, if that's what he wants, regardless of how it affects the people who love him.
It's a bitter pill to swallow for those who haven't faced their own death. For some reason until a person has been on that road themselves, they lack the understanding needed to cope with losing someone. They always feel like there is more that can be done to keep the person alive until they, themselves, are able to let go.
Is it fair to ask him to stay when you know that he's suffering?? I know you care, but he has to be allowed to deal with it in his own way.
Hope this helped a little.
Your friend may have a feeling that he is in some way burdening the family and feels guilty if that happens and doesn't want the attention.
friend turn out to be a lie not in rehab now got several cancers