Evaluation of the risk factors for febrile neutropenia associated with hematological malignancy

Febrile neutropenia (FN) can frequently become a very serious problem. In 2002, Klastersky and colleagues established the Multinational Association for Supportive Care in Cancer (MASCC) score, which consisted of risk factors for conditions that included solid tumors. However, hematopoietic tumors, in comparison to solid tumors, are plagued by such problems as the quantity and quality of abnormalities associated with leukocytes and neutrophils and the requirement for higher dosages of both radio- and chemotherapy. FN is a complication associated with hematological malignancies that can lead to a fatal outcome, but it is avoidable if the appropriate preventive treatment is performed at an early stage. The subjects of the present study consisted of 354 patients with hematopoietic malignancies who were treated at the Japanese Red Cross Medical Center Hospital, Tokyo, between August 2000 and September 2004. They were retrospectively evaluated for the risk factors of FN by applying Wilcoxon's rank sum test. A scoring index was defined and the patients were classified into high- and low-risk groups before evaluation. The following nine risk factors, which may significantly influence the relationship between the time required for defervescence and the duration of neutropenia - age; hematological diseases; the leukocyte count during the febrile period; the reduction in leukocyte count per day before the onset of FN; the prophylactic administration of antimycotic agents; sterilization of the intestinal tract; and urine albumin content, creatine level, and C-reactive protein (CRP) level - were expressed in points and their sum was termed risk points. The range of risk points was classified as 0-3 and 4-9. The time required for defervescence was 5.1 days when the risk points were in the range of 0-3 and 8.1 days when the points were in the range of 4-9. These figures were distributed normally and there was a significant difference between the two groups (P = 0.0016). FN associated with hematological malignancies is somewhat different from that related to other malignancies; it is therefore associated with unique risk factors. Most of the risk factors used in the present study can be evaluated objectively. At the onset of FN, they were expressed in points for evaluation. Further prospective studies are needed to determine whether these risk factors are suitable for use in actual cases.