Since 1993, the German Cancer Society is working on interdisciplinary standards and short guidelines for diagnosis and treatment of malignant diseases. They are developed by interdisciplinary groups of experts and by coordination with the involved medical scientific societies and several coopted partners, in particular the Scientific Advisory Board of Deutsche Krebshilfe and the Working Group of German Cancer Centers. Standard operating procedures for the development and continuous actualization and improvement are observed. Standards and guidelines are published in the book series "Quality Assurance in Oncology", in several medical journals and electronically in the world wide web.