MOBILIZATION OF PERIPHERAL-BLOOD PROGENITOR CELLS AFTER INDUCTION CHEMOTHERAPY RUBICIN-VINORELBINE-CYCLOPHOSPHAMIDE-FLUOROURACIL) AND GRANULOCYTE-COLONY-STIMULATING FACTOR IN BREAST-CANCER

In order to evaluate the mobilization of peripheral blood progenitor c ells (PBPC) after an effective induction regimen in breast cancer, we performed a study on 15 breast cancer patients, Between January 1995 a nd June 1996, these patients received TNCF (THP-doxorubicin, vinorelbi ne, cyclophosphamide, fluorouracil for four days, every 21 days) with G-CSF support (5 mu g/kg for 10 days after chemotherapy) to reduce apl asia, This regimen is known to result in a complete pathological respo nse in 30% of patients. Between two cycles of TNCF treatment, hematolo gical recovery was observed. Progenitor cells (CFU-GM and CD34(+) cell s) and mononuclear cells in DNA synthesis (MCDS) counts were performed daily, between the 12th and 17th postchemotherapy days (81 samples), The results showed a similarity for hematological recovery and PBPC mo bilization kinetics depending on the number of treatment cycles. The t hree methods used for PBPC evaluation were well correlated (P < 0.01) with an optimal mean PBPC recruitment by the last day of G-CSF adminis tration: respectively, 11 520 (1729-26 539) CFU-GM/ml of blood, 249 (1 4-1160) CD34(+) cells/mu l of blood and 211 (21-554) MCDS/mu l of bloo d. These results suggested that a daily injection of G-CSF after one o r two TNCF cycles will produce an effective PBPC mobilization in compa rison with currently used regimens.