Themyeloid growth factors in older adults with cancer
Introduction Myelosuppression represents the major dose-limiting toxicity of cancer chemotherapy regimens, particularly in older cancer patients. In addition, aging is associated with a progressive decline in the functional reserve of the bone marrow as well as other organ systems. Such age-related reductions of hematopoietic stem cells, including a progressive restriction in hematopoietic tissue, may result in an increased risk of death from infection, particularly among older patients under stress such as treatment with myelosuppressive chemotherapy. Neutropenic complications, most notably febrile neutropenia, are accompanied by considerable morbidity, mortality, and cost. The myeloid growth factors have been shown to significantly reduce the risk of neutropenic complications, including febrile neutropenia and its consequences. These agents have been integrated in modern oncology practice with recommendations based on clinical practice guidelines from several professional organizations. This chapter summarizes the rationale and potential value of these agents in the management of elderly patients receiving cancer chemotherapy. Chemotherapy-induced neutropenic complications Risk of neutropenic complications Despite improved supportive care, including a broad array of active antibiotics, febrile neutropenia and its consequences continue to be associated with frequent and prolonged hospitalization, sometimes resulting in infection-related mortality. The risk of hematologic toxicity associated with systemic chemotherapy is greatest during the initial cycles of treatment. The likelihood that patients developing neutropenic complications will experience those events during the first treatment cycle ranges from 50 to 80 percent across cancer types (Figure 23.1).
