In a randomised, multicentre study the effect of changing the combined cytostatic treatment with VAC (vincristin, adriamycin, cyclophosphamide) to FMC (fluorouracil, methotrexate, cyclophosphamide) was tested, as well as the effect of active non-specific immune stimulation with Corynebacterium parvum, and compared with a control group. In 59 of 120 patients (49%) in whom the results could be analysed there was a measurable significant regression of tumour size to less than 50% of its initial value. The course was stabilized in a further 43 (36%) women. Further tumour-growth progression or death in the early phase of treatment occurred in only 18 women (15%). Average remission was 16 months. Median survival time from start of the study in all analysable patients averaged 22 months. Patients with an ulcer at the site of application of Corynebacterium parvum had a clearly prolonged survival time. In all, immune stimulation with Corynebacterium parvum was no better, either with regard to the remission rate, remission duration or survival time.