PURPOSE: The so-called Cancer Multistep Therapy was conceived by the author in 1965. It is a combined modality treatment with 3 process steps: whole-body hyperthermia (WBH), hyperglycemia (HG) and hyperoxemia (HO). The original therapy concept was further developed into a systemic Cancer Multistep Therapy (sCMT) of high efficiency and selectivity. An outline follows of this therapy and the actual state of the sCMT concept as per 1993 (new in timing, dosage, technique). Knowledge of the synergetic-additive efficiency of various groups of cytostatics reacting to the effects of the main treatment process steps (WBH + HG + HO) led in 1974 to an extension of the sCMT concept by including chemotherapy. In addition, a radiotherapeutical treatment was included in this concept as cancer cells clearly show a higher sensibility to radiation while under the influence of sCMT. METHOD: Before commencement of whole-body hyperthermia, the blood glucose concentration is increased to approximately 27 mM in order to lower the pH values in the cancer tissues. Afterwards, the whole-body hyperthermia climaxes with a 60 ... 90 min plateau period of approximately 42 degrees C. This is achieved by means of a specially developed infrared-A irradiation machine named IRATHERM 2000. Parallel to the hyperthermia treatment, the patient inhales air enriched with oxygen at a flow rate of up to 30 l/min, which heightens the stress tolerability. Following the sCMT treatment, the patient remains under observation on an intensive in-patient basis for 24 hours before he or she is discharged for out-patient post-treatment care. During the main treatment, the body-core and skin temperatures as well as the heart and circulatory system of the patient are constantly monitored and he is subjected to a close-meshed surveillance of his glucose, lactate concentration, blood-gas, electrolyte, water and acid base values. On completion of the therapy treatment, the patient takes part in a standardised long-term dispensary programme. About 1 week before and 1 week after the main treatment day the weakened state of the patient necessitates his participation in an Oxygen Multistep Therapy with immunostimulation. RESULTS: The systemic tolerance of sCMT with minimal side-effects has been proven with several 100 patients and results have been published as part of the phase-I study [36]. A first evaluation of the efficacy of sCMT was documented in the same study. CONCLUSION: The systemic tolerability effects of sCMT on the one hand and the positive therapeutic influence on the course of the illness on the other hand, have encouraged us to carry out more research on the efficacy of sCMT, and this will be published shortly.