ERYTHROID BURST-FORMING UNITS (BFU-E) PREDICT HEMATOPOIETIC RECOVERY AFTER PERIPHERAL-BLOOD PROGENITOR-CELL TRANSPLANTATION IN PATIENTS WITH ADVANCED BREAST-CANCER

In 29 consecutive heavily pretreated stage IV breast cancer patients, we analyzed patient factors and in vitro characteristics of peripheral blood progenitor cell (PBPC) collections that might correlate with th e speed of hematopoietic recovery after autologous transplantation, PB PC collections were assessed for total number of mononuclear cells inf used/patient weight in kg and hematopoietic progenitor cell content us ing in vitro colony-forming assays, In these patients, who received PB PC as the sole hematopoietic support after myeloablative chemotherapy, the number of erythroid burst-forming units (BFU-E) infused correlate d significantly with both time to neutrophil (P = 0.008) and platelet (P = 0.0001) recovery and was a better predictor of hematopoietic reco very than number of CFU-GM administered. By day 75 after transplantati on, six patients with poor BFU-E yields failed to engraft platelets, O ur data suggest that the number of BFU-E infused correlate with time t o hematopoietic engraftment and may predict failure of platelet engraf tment in heavily pretreated patients.