[Cancer, what do we know, what can de do?].

Some epidemiologic data on the frequency of cancer and etiologic factors that especially concern the formation of malignant tumors are reported. The role of prevention and prophylaxis is discussed as well as prophylactic precautions. Regarding therapy, not only the progress of local high-frequency hyperthermia combined with bacterial oncolysis is explained, but also that of cytostatic chemotherapy. Last but not least, attention is directed to the importance of basic oncologic research.