After my breast cancer recurred and my only conventional options were to have chemotherapy and radiation, I was referred to Dr. Kleef by my integrative oncologist. I spent four weeks in Vienna in early 2018 has a variety of treatments including hyperthermia and immunotherapy. The clinic was beautiful and the staff treated me very well. The treatments were tiring but nothing like what full-dose chemo and radiation would have been as far as side effects. I am now almost four years out and thanks to Dr. Kleef's care and my continued work with my oncologist in the States, I remain in remission from my stage III breast cancer. Dr. Kleef's clinic has kept in touch with me and has been responsive to any questions I had after I got home and over the past four years. Although stage IV cancer is a much more serious diagnosis, I believe that Dr. Kleef has been able to help many people with advanced cancer live a longer and healthier life and I would definitely recommend him to others seeking integrative cancer treatment.