The traditional problem of the poor presentability as well as diagnostic and therapeutic practicability of individual patient care is still unresolved. The present book aims at leading the reader (cancer researchers, pharmacologists, biologists) away―in a scientifically accessible manner―from the daily conflicts between theory and practice and between the generalized and individual tumor patient, so that more personalized diagnostic and therapeutic strategies can be developed for controlling metastatic tumor disease: • First, recording the systems concept of tumor biology based on rather different sciences (biochemistry, cell biology, and medical oncology) including their potential contribution to communication, • then, giving reductionistically derived systems features an internal communicative context (formal-pragmatic communication theory), and • finally, binding the systems features to (tumor-immanent) evolutionary processes (modularity of biochemical and cellular processes, rationalization of biologic functions).