Neutropenia and its complications, including febrile neutropenia (FN), represent major toxicities associated with cancer chemotherapy, resulting in considerable morbidity, mortality, and costs. The myeloid growth factors such as granulocyte colony-stimulating factor (G-CSF) have been shown to reduce the risk of neutropenia complications while enabling safe and effective chemotherapy dose intensity. Concerns about the high costs of these agents along with limited physician adherence to clinical practice guidelines, resulting in both overuse and underuse, has stimulated interest in models for individual patient risk assessment to guide appropriate use of G-CSF. In a model developed and validated by the ANC Study Group, half of patients were classified as high risk and half as low risk based on patient-, disease-, and treatment-related factors. This model has been further validated in an independent patient population. Physician-assessed risk of FN, as well as the decision to use prophylactic CSF, has been shown to correlate poorly with the FN risk estimated by the model. Additional modeling efforts in both adults and children receiving cancer treatment have been reported. Identification of patients at a high individual risk for FN and its consequences may offer the potential for optimal chemotherapy delivery and patient outcomes. Likewise, identification of patients at low risk for neutropenic events may reduce costs when such supportive care is not warranted. This article reviews and summarizes FN modeling studies and the opportunities for personalizing supportive care in patients receiving chemotherapy.
Gary H. Lyman and Marek S. Poniewierski
Jeffrey Crawford, David C. Dale, Nicole M. Kuderer, Eva Culakova, Marek S. Poniewierski, Debra Wolff, and Gary H. Lyman
This study was undertaken to describe the relationship between the occurrence and timing of neutropenic events and chemotherapy treatment in a community-based population of patients with cancer. The study included 2962 patients with breast, lung, colorectal, lymphoma, and ovarian cancers from a prospective U.S. registry of patients initiating a new chemotherapy regimen. Detailed patient-, disease-, and treatment-related data, including toxicities, were captured at baseline, the beginning of each cycle, and each midcycle blood draw for up to 4 cycles of treatment. Primary outcomes included febrile neutropenia (FN), severe neutropenia without fever/infection, and relative dose intensity (RDI). Thirty-seven percent of patients were aged 65 years or older, 43.5% had an Eastern Cooperative Oncology Group performance status of 1 or greater, and 27% had 1 or more comorbidities. Reductions in RDI to less than 85% of standard in the first cycle were planned in 23.6% of patients, whereas primary colony-stimulating factor prophylaxis was used in 18.2%. In the first 3 cycles of treatment, 10.7% of patients experienced FN, with most of these events (58.9%) occurring in the first cycle. This first-cycle pattern was consistently observed despite wide variations in event rates by tumor type, disease stage, chemotherapy regimen and dose, and patient characteristics. Despite frequent planned reductions from standard RDI, the incidence of FN remains high in community oncology practice in the United States. Improved methods of pretreatment assessment of patient risk factors for neutropenia are needed.