Total body irradiation, cyclophosphamide, and etoposide with stem cell transplant as treatment for infants with acute lymphocytic leukemia

Background. Acute lymphoblastic leukemia (ALL) in infants has a very poor outcome with modern chemotherapy. We reviewed our experience with the infants diagnosed with ALL at Children's Memorial Hospital from 1992 to 1997. Procedure. During this time period, 10 infants were diagnosed with ALL. Seven of them were transplanted, four with marrow from HLA-matched siblings and three with umbilical cord blood. Four of the transplanted patients had the MLL gene rearrangement and the other three transplanted patients had one or more other high-risk features including CD10-blasts, age less than 6 months at diagnosis, or prior relapse. The patients were conditioned with a regimen of total body irradiation (TBI), etoposide, and cyclophosphamide (CY). Peritransplant toxicity was tolerable. The graft infused contained a median total nucleated cell dose/kg of 3 x 10⁸ (.3 x 10⁸-6 x 10⁸). The median CD34+ cell dose/kg was 5 x 10⁶ (.25 x 10⁶-31 x 10⁶). Results. All of the patients engrafted with a median of 18 days (11-29) to reach an absolute neutrophil count (ANC) of 500/μl. The median time to reach an unsupported platelet count greater than 20,000/μl was 24 days (1864). Four of seven of the transplanted patients are leukemia-free survivors at a median follow-up of 775 days. Of the three patients who were not transplanted, one is surviving 2+ years off therapy. Conclusions. Allogeneic stem cell transplant is an alternative to chemotherapy alone as a treatment for infant ALL when a suitable donor is available.