OBJECTIVETo observe the combined effect of etoposide (Vp-16) and recombinant human granulocyte colony-stimulating factor (rhG-CSF) on mobilization of autologous peripheral blood stem cells (APBSC) in malignant tumor patients and find out the suitable dose of Vp-16.

METHODSThirty patients were randomly divided into two groups, 15 in each group. In group A, Vp-16 1000 mg/m(2) was injected intravenously in six divided doses, for 2 hours every 12 hours on day 1, 2 and 3. In group B, Vp-16 1500 mg/m(2) was injected intravenously in six divided doses for 3 hours every 12 hours on day 1, 2 and 3. rhG-CSF was given as a single daily injection subcutaneously at the dose of 300 microg.body(-1).day(-1) from the day of the nadir of white blood cell (WBC) to the day before the end of APBCS harvest. APBSC harvest started when WBC > or = 5.0 x 10(9)/L and finished when accumulated mononuclear cells (MNC) > or = 5 x 10(8)/kg or CD34+ cells > or = 2 x 10(6)/kg.

RESULTSThere was no significant difference between the time of nadir, nadir of WBC, absolute neutrophil count (ANC), the beginning time and continuous time of rhG-CSF given, the beginning time and continuous time of APBSC harvest. When the blood volume, flow rate and continuous time of apheresis were similar in each apheresis in the two groups, the number of APBSC in each harvest and total number of APBSC were also not significantly different between the two groups. The side effects induced by Vp-16 were also not significant different between the two groups.

CONCLUSIONVp-16 combined with rhG-CSF is a safe and highly effective method for APBSC mobilization, 1000 mg/m(2) and 1500 mg/m(2) of Vp-16 possess similar efficiency and side effects for APBSC mobilization.