Peripheral progenitor cells (PBPC) in supportive care after high-dose chemotherapy in breast cancer

Hemopoietic growth factors (HGF) and leukapheresed peripheral progenitor ce lls (PBPC) are increasingly used for supportive care in high-dose chemother apy (HDC) of solid tumors. Presently, therapeutic protocols with cyclic HDC plus PBPC support are successfuly used in breast cancer patients. Administ ration of PBPC significantly influences hemopoietic recovery in terms of sh ortening the pancytopenia period which reduces the risk of dangerous compli cations, especially the risk of infection. As a certain controversy exists about efficacy of this therapy, large rando mized studies are conducted to find more accurate conclusions. In 1998 Nati onal Cancer Institute (NCI) gave top priority to four randomized studies of HDC with PBPC support. In recent years, rising yields of PBPC are obtained. The use of new combina tions and dosages of hemopoietic growth factors leads to a significant incr ease of progenitor cells circulating in peripheral blood. Effective mobiliz ation regimens combinations of chemotherapy and cytokines - enable to incre ase the numbers of circulating progenitors as much as 100-fold. Another asp ect, how to minimize the risks is to reduce the transplant volume and so re duce the amount of cryoprotective agent DMSO (dimethyl sulfoxide) and hemol ysed erythrocytes. This led to the idea to use only whole blood enriched fo r PBPC. At present it has been used also in our patients. The results show that enriched whole blood can be used as sufficient substitution for suppor t in intensive cyclic chemotherapy in breast cancer patients.