I've been online a lot lately looking for foods to help my uncle's newly diagnosed prostate cancer. I've been surprised at how much good information is out there when you start poking around, so I'm sure the same would be true for natural remedies for his specific condition-I'm sure you already know that and sorry you're in such a hurried situation. In conjunction with his treatment, natural remedies, positivity and prayer are the best and strongest things you can do. The suggestion about Reiki is excellent, I hope he can access that where he is. He's lucky to have you caring for him, and I'll add him to my family's prayer group as well.
Here's a good list on Dr Sear's website for white blood cell building foods and herbs: http://www.askdrsears.com/html/4/t042500.asp
Best hopes and prayers to you
a m y