To apply recombinant human (rh)erythropoietin (EPO) to predeposit autologous blood donation (P.A.B.D.) in cancer patients clinically, (1) we tested the effects of rh-EPO on 2 ovarian cancer cell lines in vitro at first, then, (2) studied the effect of the rh-EPO for switch back (SB) method that is a variant of P.A.B.D. clinically. Rh-EPO (0.068-68U/ml) caused no significant and reproducible stimulation of clonal growth to SHIN-3 (derived from serous cyst adenocarcinoma) and MN-1 (derived from mucinous cyst adenocarcinoma). Twenty-five cases were studied. The change in the hemoglobin concentration (delta Hb) was -0.43 +/- 1.38g/dl (mean +/- SD) and the change in the total amount of hemoglobin (total delta Hb) which is calculated on the basis of whole blood volume was 111.5 +/- 53.2g/body in 16 cases with rh-EPO. The delta Hb and total delta Hb were -3.25 +/- 0.78g/dl and 30.1 +/- 41.7g/body in 9 cases without rh-EPO. The rh-EPO combined cases were significantly increased in both delta Hb and total delta Hb (p < 0.05, unpaired student t test). We therefore conclude that it would be very beneficial to use rh-EPO combined with the SB method in P.A.B.D. for high maximum surgical blood order schedule (MSBOS) cases such as gynecological malignancies.