New Tool Provides Cycle-Specific Score to Predict Febrile Neutropenia After Chemotherapy

The ^CSRFENCE risk score is a newly created tool that predicts the risk of febrile neutropenia (FN) in chemotherapy cycles after the first—an area of need, especially in high risk populations.

In many highly myelosuppressive chemotherapy regimens, FN becomes a very relevant adverse event to be on guard for that leads to poorer cancer treatment outcomes. Previously, guidelines have suggested focusing on predicting FN risk in the first cycle because patients who are at high risk during the first cycle are likely to be at greater risk during future cycles. The development of the original FENCE score was created for this reason: to predict the risk of FN in the first cycle.

However, certain risk factors, such as experiencing FN in a previous cycle or a dose delay, will only appear in later cycles after the first, which the FENCE score does not consider. To address this issue, researchers sought to develop a new FENCE score, ^CSRFENCE, to help predict the risk of FN in chemotherapy cycles 2 to 6.

Patients on first-line chemotherapy were followed through cycles 2 to 6 and assessed for FN, which was defined in this study as neutrophils < 0.5 x 10⁹/L or leukocytes ≤ 2.0 x 10⁹/L. Risk factors identified were previous FENCE risk group, sex, body surface area, Charlson Comorbidity Index score, hemoglobin, leukocyte, platelet levels, the type of chemotherapy drug, radiotherapy, previous FN or neutropenia, dose delays, dose reductions, cycle number, and prophylactic use of granulocyte colony-stimulating factors (G-CSF).

In this study, FN occurred in 324 of the 15,419 cycles among the 4590 patients in the derivation group. FENCE risk groups were categorized into low, intermediate, high, and very high risk and scored accordingly, with higher risk scoring higher. Anemia, chemotherapy drugs with high risk of myelosuppression (platinums, taxanes), and radiotherapy also increased the risk score. Previous FN or neutropenia depended on the number of FN or neutropenia events with a greater frequency of events scoring higher. Prophylactic G-CSF and cycle number lowered risk score, with future cycle numbers reducing FN risk scores.

The tallying of all the different components leads to the ^CSRFENCE risk score. ^CSRFENCE is differentiated into low risk (score ≤32), intermediate risk (score 33-63), and high risk (score ≥ 64). The numbers needed to treat with G-CSF to avoid 1 FN event over 21 days were 748 in the low, 121 in the intermediate, and 34 in the high-risk group.

The ^CSRFENCE risk score is a useful tool to calculate and predict FN risk in chemotherapy cycles after the first and can guide clinicians in monitoring and using preventative measures for high risk patients. Although the ^CSRFENCE was able to separate patients into 3 clinically distinct risk groups, more validation will be needed to determine if this is a valid scoring system in all types of patients with cancer.

Reference

Aagaard T, Reekie J, Roen A, et al. Development and validation of a cycle-specific risk score for febrile neutropenia during chemotherapy cycles 2-6 in patients with cancer: the ^CSRFENCE score. Presented at: 2018 IDWeek; October 5, 2018; San Francisco, CA. Abstract 1549. https://idsa.confex.com/idsa/2018/webprogram/Paper69248.html.