Study Finds CISNE Model Effective for Guiding Treatment-Setting Decisions for Febrile Neutropenia

Previous research has indicated that patients with low-risk febrile neutropenia can be treated safely and effectively in the outpatient setting. However, as most patients experiencing acute illness visit the emergency department, emergency physicians must be able to determine which patients with febrile neutropenia should be treated in the outpatient setting and which should be treated in the inpatient setting.

A new study comparing 2 risk stratification models found that the Clinical Index of Stable Febrile Neutropenia (CISNE) Model is useful for identifying low-risk patients with febrile neutropenia, but the combination of the CISNE Model with the Multinational Association of Supportive Care in Cancer Risk Index Score (MASCC RIS) may help emergency physicians cope with febrile neutropenia more confidently.

“To predict low-risk febrile neutropenia, MASCC RIS shows high sensitivity, but it has low specificity regarding solid tumors,” explained the researchers. “The low specificity entails high false-positive rates to predict low-risk febrile neutropenia, leading emergency department physicians to take a risk of sending back some patients for outpatient treatment who should have been hospitalized.”

The researchers followed 400 patients with febrile neutropenia who visited the emergency department of the National Cancer Center in Korea and had treatment with cytotoxic chemotherapy for solid tumors in the last 30 days between January 2010 and December 2016.

The 299 (74.8%) patients determined apparently stable were stratified into 3 groups based on CISNE scores: CISNE 1 or low risk (56 patients), CISNE 2 or intermediate risk (124 patients), and CISNE 3 or high risk (119 patients). Scores were based on 6 variables: Eastern Cooperative Oncology Group performance status, history of chronic obtrusive pulmonary disease, history of chronic cardiovascular disease, oral mucositis, monocyte counts, and serum glucose level to identify stress-induced hyperglycemia. Clinical factors relevant to MASCC RIS score were also collected.

According to the researchers, monocyte counts were significantly lower as the risk rose: 453/mm³ in CISNE 1, 140/mm³ in CISNE 2, and 40/mm³ in CISNE 3. However, the severity of neutropenia among the groups was not significantly statistically different.

Patients in CISNE 2 and 3 groups also experienced acute kidney injury, acute heart dysfunction, arrhythmia, acute respiratory failure, and delirium. The remaining serious complications were relatively infrequent, the researchers reported.

The frequency of any serious complications was 6 patients (10.7%), 24 patients (19.4%), and 40 patients (33.6%) in CISNE 1, 2, and 3, respectively. When applying the MASCC risk index, 3 patients (5.4%) in CISNE 1, 5 patients (4%) in CISNE 2, and 16 patients (13.4%) in CISNE 3 belonged to the MASCC high-risk group.

“Notably, all 6 patients who experienced the primary outcome in CISNE 1 had nothing by hypotensive episodes,” noted the researchers.

Reflecting on the findings, the researchers proposed that the combination of both models may prove beneficial for identifying patients with low-risk febrile neutropenia. They argue that emergency physicians can use MASCC RIS to quickly identify unstable patients, as the model has high sensitivity. For seemingly stable patients, a final decision on hospitalization can be determined by CISNE score.

Reference

Moon H, Choi Y, Sim S. Validation of the Clinical Index of Stable Neutropenia (CISNE) model in febrile neutropenia patients visiting the emergency department. Can it guide emeergency physicians to a reasonable decision on outpatient vs. inpatient treatment? [published online December 31, 2018]. PLOS One. doi: 10.1371/journal.pone.0210019.