International Society of Paediatric Oncology (SIOP)The International Society of Paediatric Oncology (SIOP) was founded in the late 1960’s. It has grown into a dynamic and vibrant global organisation. SIOP has over 1000 members worldwide including doctors, nurses, other health-care professionals, scientists and other researchers. Our members are dedicated to increasing knowledge about all aspects of childhood cancer. Our aim is to improve and optimise treatments throughout the world.