Myeloid
growth factors are used to reduce myelotoxicity and the risk of
infection after
cancer chemotherapy and in patients with chronic
neutropenia. This article addresses the long-term benefits and risks associated with
granulocyte colony-stimulating factor (
G-CSF)
therapy in both settings. A systematic review of randomized controlled trials recently reported long-term outcomes regarding the risk of
second malignancies and overall survival. Based on these studies, the risk for
acute myeloid leukemia (AML) associated with known carcinogenic agents, such as
chemotherapy, could not be distinguished from any risk associated with
growth factor support. However, the enhanced delivery of
chemotherapy dose intensity enabled by the use of
G-CSF in these studies was associated with a significant reduction in all-cause mortality. Although some reduction in treatment-related mortality with
G-CSF support may occur, the observed improvement in long-term survival likely relates to better disease control with more-intense
G-CSF-supported
chemotherapy. Myeloid
growth factors have also been shown to benefit patients with
severe chronic neutropenia. Almost all patients with cyclic, congenital, or idiopathic
neutropenia experience response to G-CSFs. Treatment is titrated to determine a dose that provides a safe elevation in neutrophil counts. Reports have shown that patients can be maintained for years at the same dose after adjusting for growth and development. In
congenital neutropenia, the inherent risk of developing
myelodysplastic syndromes or AML requires careful monitoring, including routine blood counts and annual bone marrow examinations.