You Win Some, You loose Some in God, With Skin On

I hate to lose. Show me someone who is a good loser and I will show you a loser. But I digress. I got a call this morning that I was afraid of was coming yet hoped I was wrong. Cancer once again is going to win and I am angry about it.
I have spent hours praying that God would spare this person. I have begged and pleaded but to no avail. Once again the cards were stacked against me and the person. Why do I take it so hard? I am a cancer survivor so I know God can, and if ever a person deserved to have a second chance, this dear lady does.
Are my prayers wasted when I know that no one has survived this type of cancer? Is this a cancer that is even too difficult for God? I pray with the person for God to heal them, and I believe He can but He chooses not to. That is a part of faith that I do not understand. And this cancer is spreading fast.