A model to predict chemotherapy-related severe or febrile neutropenia in cycle one among breast cancer and lymphoma patients

8068 Background: Chemotherapy used to treat cancer may produce severe (absolute neutrophil count ≤250/mm3) or febrile neutropenia (SFN), which often results in fever, infection, and hospitalization. This can lead to dose delays or reductions in subsequent chemotherapy cycles and/or early termination of therapy. Recent studies suggest most patients who experience SFN do so early in the course of chemotherapy, in particular during the first cycle. Several recent risk models for neutropenia have identified baseline patient characteristics that predict the occurrence of neutropenia. The ability to identify patients at risk for developing neutropenia early in their therapy might help guide appropriate hematopoietic growth factor use. We evaluated possible risk factors associated with cycle 1 SFN among a sample of patients with NHL or breast cancer. Methods: A historical case series of 1,617 patients (704 NHL and 913 early-stage breast cancer) who received initial chemotherapy at 16 community and academic oncology practices between 1991 and 1999 were selected for study. SFN was defined as absolute neutrophil count ≤250/mm3 or febrile neutropenia. Results: A total of 461 patients (29%) experienced at least one SFN episode; 268 (58%) of these patients (167 [59%] with NHL and 101 [56%] with breast cancer) had SFN in cycle 1. Risk factors associated with cycle 1 SFN included age ≥65 years (Odds ratio [OR] 2.08; 95% CI: 1.48–2.92), baseline hemoglobin <12.0 g/dL (OR 1.90; 95% CI: 1.41–2.58), presence of heart, renal, or liver disease (OR 2.12; 95% CI: 1.03–4.36), NHL (OR 1.64; 95% CI: 1.16–2.32), planned full chemotherapy dose intensity (OR 2.74; 95% CI: 1.55–4.84), and no growth factor in the first 5 days of cycle 1 (OR 1.82; 95% CI 1.07–3.08). Conclusions: Data routinely available to the clinician can help identify patients at risk for SFN in cycle 1. In our model assessing chemotherapy-related SFN in breast cancer and lymphoma, patients ≥65 were twice as likely to have SFN in Cycle 1. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Amgen, Inc. Amgen, Inc.; Schering-Plough Amgen, Inc. Amgen, Inc.