THE ADDITIVE EFFECT OF PERIPHERAL-BLOOD STEM-CELLS, HARVESTED WITH LOW-DOSE CYCLOPHOSPHAMIDE, TO AUTOLOGOUS BONE-MARROW REINFUSION ON HEMATOPOIETIC RECONSTITUTION AFTER ABLATIVE CHEMOTHERAPY IN BREAST-CANCER PATIENTS WITH LOCALIZED DISEASE

The additive effect of peripheral blood stem cells (PBSCs) to autologo us bone man ow transplantation (ABMT) on haematopoietic reconstitution , after ablative chemotherapy in patients with locally advanced breast cancer, was evaluated. Patients were treated with induction chemother apy, followed by ablative chemotherapy consisting of mitoxantrone and thiotepa. Group I (n=14) received ABMT and granulocyte macrophage-colo ny stimulating factor (GM-CSF), group II (n=11) received ABMT, PBSCs a nd granulocyte-colony stimulating factor. (G-CSF). PBSCs were harveste d after a low-dose cyclophosphamide (750 mg/m(2)), followed by G-CSF. Stern cell harvest was routinely started 12 days after cyclophosphamid e. Compared to group I, group II showed a significant reduction in the median number of days for leukocytes < 0.5 x 10(9)/L 4.5 days, leukoc ytes < 1.0 x 10(9) / l 5.5 days, platelets < 20 x 10(9) / l 9 days and platelets < 40 x 10(9) / l 12.5 days. The median number of transfusio ns of platelets fell from 11.5 to 7 and of red blood cells from 8.5 to 6. The median hospitalisation duration declined from 40.5 to 30 days, fever above 38 degrees C with 7.5 days, fever above 38.5 degrees C wi th 4 days and antibiotic treatment with 8.5 days in group I versus gro up II. Improvement of haematological recovery, duration of fever and h ospitalisation was observed by the addition of PBSCs, obtained after a relatively low-dose cyclophosphamide and G-CSF and stem cell pheresis on fixed days, to autologous bone marrow and growth factor in the per iod after ablative chemotherapy.