ONCOLOGY Vol 20 No 14_Suppl_9

Myelosuppression and particularly neutropenia and associated complications, including febrile neutropenia, continue to represent the major dose-limiting toxicity of cancer chemotherapy.

Anthracycline- and taxane-based adjuvant chemotherapy regimens have become the most commonly used regimens in the United States for high-risk, early-stage breast cancer. Growth factor support is an essential component of therapy for several of the most commonly used adjuvant chemotherapy regimens that frequently cause substantial myelosuppression and anemia. Extensive data now exist to demonstrate the efficacy of both long- and short-acting myeloid growth factors in patients receiving dose-dense AC → paclitaxel. This article will explore prophylactic use of both filgrastim (Neupogen) and pegfilgrastim (Neulasta) in recent clinical trials.

The chemotherapy of most cancers may be beneficial to older individuals as long as patients are selected on the basis of their life expectancy and functional reserve, conditions that may interfere with the tolerance of chemotherapy are corrected, and adequate doses of chemotherapy are administered. Prevention of neutropenia-related infection may both improve the outcome of cancer and reduce the risk of toxic deaths in older patients. The prophylactic use of myelopoietic growth factors is recommended in individuals aged 65 and older when the risk of chemotherapy-induced neutropenic infection is at least 10% or higher. In this article we explore the management of neutropenia and neutropenic infections in older cancer patients, as well as review the causes and the risk of this complication.

Grade 3 and 4 neutropenia as well as febrile neutropenia have been demonstrated to occur in all tumor types and are clearly associated with major morbidity and significant mortality; this is particularly true when myelosuppressive regimens are used with curative intent as is the case in most breast cancer and non-Hodgkin's lymphoma regimens. Myeloid colony-stimulating factors (CSFs) substantially decrease the risk of severe and febrile neutropenia. Although the white cell growth factors might not be cost-effective at lower risks of febrile neutropenia, they clearly benefit other outcomes such as the incidence of severe neutropenia and febrile neutropenia, hospitalization, and mortality. Updated guidelines from the American Society of Clinical Oncology, the National Comprehensive Cancer Network, and the European Organisation for Research and Treatment of Cancer now recommend primary prophylaxis or first-cycle use of white cell growth factors with regimens where the occurrence of febrile neutropenia is approximately 20% (as well as when other risk factors are present). This article briefly describes the rationale for the development of several of the guideline changes as well as highlights some of the ongoing issues related to the use of CSFs.