The aim of our project was to compare the efficacy of mobilised whole blood versus cryopreserved PBPC (peripheral blood progenitor cells) obtained by leukapheresis in the support of hematopoietic recovery in cyclic intensive chemotherapy. Twenty-nine women with breast carcinoma were treated. The mean age was 46 years. In stage III were 23, in stage IV were 6. They received 6 cycles of epirubicin 150 mg/m2 and cyclophosphamide 1250 mg/m2. In the first cycle, 24 hours after chemotherapy, application of G-CSF 5 microg/kg/day was started, and discontinued when leukaphereses and whole blood collections were done. Leukapheresed progenitors were then divided into 3 aliquots, cryopreserved and reinfused after the 4th, 5th and 6th chemotherapy cycles. Mobilised whole blood was collected on day 14 of the 1st and 2nd cycles and reinfused 24 hours after chemotherapy. The occurrence of grade IV leukopenia was 1.82 times higher with whole blood support and grade IV thrombocytopenia 2.64 times higher than in cycles with cryopreserved PBPC support. This resulted from the fact that in one application the numbers of CD34+ cells and CFU-GM were nearly double in cryoconcentrates. The yields of CD34+ cells in 450 ml of whole blood were 1.8 x 10(6)/kg, which is not sufficient for optimal hemopoietic recovery.