Peripheral blood progenitor cell collections in cancer patients: analysis of factors affecting the yields

Background and Objective. peripheral blood progenitor cells (PBPC) are now widely used to restore hematopoiesis following high dose chemotherapy in pa tients with malignancies. We sought to identify parameters that could predi ct the yield of PBPC after mobilization with chemotherapy (CT) with or with out granulocyte colony-stimulating factor (G-CSF) in cancer patients. Design and Methods. One hundred and fifty patients underwent 627 PBPC colle ctions during the recovery phase following CT with (n = 469) or without (n = 142) G-CSF. Hemogram, CFC-assays and CD34(+) cell count were performed on peripheral blood and leukaphereses products. After log transformation of t he data, differences between groups were assessed with the unpaired t-test or one-way analysis of variance. Results. Seventeen and two patients required 2 and 3 mobilization cycles re spectively to reach our target of 15x10(4) CFU-GM/kg. In patients with lymp homa but not in those with leukemia, the yields of both CFU-GM and CD34(+) cells/kg were dramatically increased when G-CSF was added to CT for mobiliz ation. In collections primed with CT and G-CSF, better yields were obtained In patients with breast cancer or small-cell lung carcinoma (SCLC) as oppo sed to other solid tumors and leukemia. Among potential predictive factors of CT- and G-CSF primed harvests, we found that the CD34(+) cell count in p eripheral blood (PB) was strongly correlated with both the CFU-GM and CD34( +) cell yields. Except in leukemia patients, more than 1x10(6) CD34(+) cell s/kg were harvested when the CD34(+) cell count in blood was above 20x10(6) /L. Similarly, better results were obtained in collections performed when t he percentage of myeloid progenitors in blood on the day of apheresis was a bove 5% or when the leukocyte count in blood was above 5x10(9)/L. Interpretation and conclusions. A diagnosis of breast cancer or SCLC, a leu kocyte count: in PB of more than 5x109/L, more than 5% myeloid progenitors or more than 20x10(6) CD34(+) cells/L in PB were associated with higher yie lds of PBPC in collections mobilized with CT+G-CSF. (C) 1999, Ferrata Stort i Foundation.