Robert Knobler, MD of the Medical University of Vienna, Vienna, Austria talks about extracorporeal photopheresis in the treatment of cutaneous T-cell lymphoma (the particular varient being Sézary syndrome) at the 2016 World Congress on Cancers of the Skin (WCCS) and the Congress of the European Association of Dermato-Oncology (EADO) in Vienna, Austria. Extracorporeal photopheresis was invented in 1983 and became well known worldwide in 1987 when the first study was published in the New England Journal of Medicine. Prof. Knobler’s role was to review the literature and the progress that has been done in the past 30 years in the use of this therapy. The literature of over 37 published papers (review articles and retrospective studies) have been reviewed and it has been found that the efficacy of this therapy, which was shown to be significant in inducing complete remission (CR) in refactory patients as well as patients who were responding to other therapies but not optimally, has been reproduced in over 1200 patients that were treated with this technology. The complete remission (CR) rates and response rates fluctuate around the same numbers as in the New England Journal of Medicine. He goes on to explain that the side effect profile of this treatment is extremely low and that is why the therapy is attractive for these patients. There has been an increase in studies from the US and Europe trying to figure out how this therapy works. This is because, even though it is a very simple therapy based on dermatological photochemotherapy, we still do not understand the mechanisms of action completely. He explains that during this treatment the combination of UVA light and psoralen induceds apoptosis and the introduction of apoptopic cells into the bloodstream enhances and provokes an immune response which seems to assist the body to contol the disease known as Sézary syndrome. He explains that the European Organisation for Research and Treatment of Cancer (EORTC) is in the process of organizing a prospective one arm trial to test the recommendations of the European Dermatology Forum guidelines on how exactly to use this therapy in treating these patients.