Prospective Multicenter International Observational Study for Determination of a Cutaneous Lymphoma International Prognostic Index Model and Impact of Major Therapies in Patients With Advanced Mycosis Fungoides and Sézary Syndrome

The purpose of the study is to develop a prognostic index model for the rare disease of mycosis fungoides and sezary syndrome. This will be done by collecting standardized clinical data at various institutions. The investigators hope this will enable the identification of low- and high-risk groups for survival in order to improve patient care and outcome.