Brett,
I don't know where you come out on medical doctors, but I would very strongly encourage you to prod your father into seeking out naturopathic medical care and make him watch a documentary called "World Without Cancer" which you can watch for free on youtube.
Lawrence Blanchard is a naturopathic physician in South Central, Texas and I can pass along his contact information via private message if you wish. Btw, Lawrence wrote four CI books a few years ago, and in the past couple of years has been writing the Biblical Heritage book series.
http://www.yourbiblicalheritage.com He's a dear friend, and among the most noble of spirits I have found among our fellowship.
Your dad needs to understand that this thing called cancer is not an infection. It is a mutation caused in almost every case by bad diet - you don't fix biochemical living process that have gone awry with synthetically manipulated non-living materials. This is why the cancer treatment rate among oncologists is so pitiful, despite the billions of dollars that all these sheeple and their pink ribbon wearing cohorts have pumped into that industry.
I'm sorry for the rant, but I hope you'll really take a very deliberate look into what I'm trying to detail here for you.
In the meantime, I wish your old man well.