Peripheral blood stem cell transplantation for breast cancer patients with bone marrow metastases using GM-CSF priming.

Twenty-seven patients with metastastic breast cancer to the bone marrow underwent successful collection of peripheral blood progenitor cells (PBPC) following GM-CSF cytokine priming and were engrafted following courses of high-dose chemotherapy. Myeloid engraftment was observed in a median of 12 days, with a range of 8-29 days. The cell dose infused correlated, although weakly, with days to engraftment, although assays of CFU-GM and CD34+ cells did not, suggesting refinement in such assays is needed. The failure to observe complete remission of the tumor suggests alternative chemotherapy regimens should be investigated.