The use of CD34+-selected PBPC after high-dose chemotherapy in breast cancer patients is associated with prolonged recovery time and increased infectious complications.

Abstract

High-dose chemotherapy with autologous stem cell rescue can result in autotransplantation of tumor cells. A possible approach to reduce tumor cell contamination is the positive selection of CD34+ PBPC, but this might be associated with a prolonged recovery time as well as an increased risk of infectious complications because of the loss of committed progenitor cells. To investigate this aspect, we compared two sequentially treated cohorts of high-risk breast cancer patients. Both groups received the same high-dose chemotherapy regimen followed by autologous peripheral stem cell transplantation. Group I received CD34+-selected blood progenitor cells, and group II received nonselected blood progenitor cells. We compared these two identically treated groups with regard to recovery time, need for blood products, infectious complications, need for antibiotic treatment, and length of the transplantation-related hospital stay. We found a prolonged recovery time for neutrophils up to 0.5 x 10(9)/L (14 days in the selected group/10 days in the nonselected group) and platelets up to 30 x 10(9)/L (29/12 days), associated with an increased requirement for RBC transfusions (5/3 U) and platelet transfusions (10/2 U). The rate of severe infectious complications (2/0), the need for nonprophylactic antibiotic treatment (15/10), and the length of the hospital stay (25/21 days) in group I were also increased. We conclude that positive selection of PBPC should not be used routinely until randomized studies show a clear long-term benefit of using CD34+-selected stem cell products in breast cancer patients.