Kathy,
I underwent cancer surgery in October 2000. My biopsy showed squamous cell carcinoma with a note that said "the neoplasm extends to the surgical margins" or basically, they probably did not get it all. I consider our family to be very religious and we prayed, and continue to pray, a great deal for healing. In conjunction with the prayer, I also knew that my best course of action was to follow my doctor's advice and remove any suspect tissue/bone. I had three teeth and a portion of my upper jaw bone removed, the biopsy of the removed tissue and bone showed no sign of cancer. Do I regret having surgery, no way! I feel that I have done all that I can do to beat this disease. The biopsy of the tissue/bone removed during surgery was not all inclusive so there may have been some cancer cells they did not find, or there may not have been any cancer remaining, It really doesn't matter. I have the peace of mind knowing I've done all that I can do from a spiritual and medical view. I am currently recovering from reconstructive surgery to replace the bone and eventually will have dental implants placed to replace the teeth I lost. I have no regrets, your friend needs to know that the decisions he makes affect not only his life but the lives of all who love and care for him. If he is not willing to seek conventional treatment for himself, maybe he can be convinced to do it for others who need him. Continue to pray and accept the tools offered up in answer to your prayers.
Best of Luck to you and your friend!