Sarah, I just read this thread. I have said a prayer for your daddy, and for you and the rest of the family. It is a lot to deal with... especially coming so soon after your sister.
My husband is a colorectal cancer survivor. It's been just over two years since his emergency surgery. The Lord truly intervened. The surgeon didn't think it was possible that it hadn't spread because it was such a large mass. But it was truly a miracle. And it was due to the power of prayer! God does still perform miracles sometimes. And sometimes he uses the illness to bring others closer to him. With my husband he did both.
Bless you and I will keep checking this thread and praying!
Love and hugs!