Hematopoietic growth factors in the prevention of infections complications in children with hematologic-oncologic diseases

Abstract

The hematopoietic colony-stimulating factors have been introduced into clinical practice as additional supportive measures that can reduce, but not eliminate infectious complications associated with therapy-induced neutropenia. Over the past decade, we have begun to appreciate the subtler aspects of the proper use of G-CSF and GM-CSF, identifying appropriate indications and contraindications. In the course of evaluating the multitude of studies, a set of formal recommendations have been propagated for the judicious use of these expensive growth factors. To prevent serious infection, the use of G- or GM-CSF is recommended in a subset of pediatric cancer patients shortly after receiving chemotherapy or a marrow transplant. Children with intensive chemotherapy (e.g., children with high risk ALL, NHL or metastatic neuroblastoma) seem to benefit from hematopoietic growth factors whereas it is not clear that this applies to children undergoing therapy for solid tumors such as rhabdomyosarcoma or Ewing's sarcoma. An exciting development is the use of G-CSF and GM-CSF to mobilize peripheral-blood progenitor cells. Future studies in pediatric cancer patients are clearly warranted to address several issues. Prospective clinical trials are still needed to define specific treatment groups who can benefit from growth factor support. In this regard, efforts must be directed at better defining the endpoints and in particular, assigning value to reduction in treatment of possible infectious complications, such as days in hospital, antibiotic usage and costs. In addition, randomized studies are required to evaluate the proper dosage and duration of therapy, which most likely will vary between groups, depending upon underlying malignancy and therapy given. In addition, combinations of different growth factors have to be tested, particularly if ex vivo expansion and the storage of hematopoietic stem cells are to be utilized in a wider spectrum of patients.