I would start with the approach in "Cancer as a Turning Point," by Lawrence LeShan. Using a form of psychotherapy, he had a 50% complete remission of Stage IV cancer with his patients. (I live using this method, though cancer is one illness I have not faced.)
I would also strongly recommend books by Dr. Bernie Seigel, such as "Peace, Love, and Healing," and "Love, Medicine, and Miracles." He is a cancer surgeon himself, and creator of the ECAP (Exceptional Cancer Patients) program. He believes that people will have the best chance of healing themselves using whatever they believe will work.
My own methods would be primarily alternative and holistic, including prayer, meditation, diet, exercise, Qigong, etc. But that's me. I honor those who choose to include Western paths. My challenges are with infections, and I use antibiotics when truly necessary - including this week!
Here is one that helps everyone. Go outside or look out a window to the East as early as you can in the morning. Hold a clear glass with an inch of water in it up to the dawn light. Say, "Energy of the Dawn, Light of the Morning Sun, Angels, and guides, please fill the water in this glass with medicine for my healing."
Take three breaths, then say, "Drinking this water, I receive the medicine into my body and being," then drink the water.
Take three breaths, then say, "May my illnesses be healed and may I be transformed."
Take three breaths and say "Thank you."