Ithy - Understanding the CISNE Score: A Tool for Assessing Febrile Neutropenia Risk

Key Insights into the CISNE Score

Purpose: The CISNE (Clinical Index of Stable Febrile Neutropenia) score is a validated tool designed to identify patients with febrile neutropenia who appear clinically stable but are at risk of developing serious medical complications.
Components: The score considers several clinical and laboratory variables, including performance status, presence of chronic diseases, oral mucositis, monocyte count, and stress-induced hyperglycemia, to stratify patients into different risk categories.
Clinical Utility: CISNE helps clinicians, particularly in emergency settings, make informed decisions regarding patient management, including the potential for outpatient care versus the need for inpatient hospitalization. It has shown better specificity than the MASCC score in identifying low-risk patients with solid tumors.

What is the CISNE Score?

The Clinical Index of Stable Febrile Neutropenia (CISNE) score is a prognostic tool specifically developed to assess the risk of serious complications in adult cancer patients who present with febrile neutropenia and appear clinically stable. Febrile neutropenia is a common and potentially life-threatening complication of chemotherapy, characterized by a fever and a low neutrophil count. While many patients may appear stable initially, they can be at risk for rapid deterioration due to underlying infections or other complications.

The CISNE score was created to provide a more objective and reliable method for risk stratification in this specific patient population. It aims to improve upon earlier tools like the Multinational Association for Supportive Care in Cancer (MASCC) score, particularly in its ability to identify patients who, despite appearing stable, have a higher likelihood of experiencing adverse events.

Development and Validation

The CISNE score was developed based on a cohort of patients with febrile neutropenia and subsequently validated in multi-center studies. These studies demonstrated its effectiveness in discriminating between patients at low, intermediate, and high risk of complications. The validation process has shown that even in seemingly stable patients, a relevant rate of serious complications can occur, highlighting the importance of accurate risk assessment tools like CISNE.

Components of the CISNE Score

The CISNE score is calculated based on six key clinical and laboratory variables. Each variable is assigned a specific point value, and the sum of these points determines the patient's overall risk score. The higher the score, the greater the risk of complications.

Variables Included in CISNE

Eastern Cooperative Oncology Group (ECOG) Performance Status

This measures a patient's level of functioning. A score of 2 or greater indicates a lower functional status and is associated with a higher risk of complications, thus contributing points to the CISNE score.
History of Chronic Obstructive Pulmonary Disease (COPD)

The presence of underlying lung disease like COPD increases the risk of respiratory complications and contributes a point to the score.
History of Chronic Cardiovascular Disease

Pre-existing heart or blood vessel conditions can increase the vulnerability to complications during febrile neutropenia, adding a point to the score.
Oral Mucositis

Inflammation and sores in the mouth (National Cancer Institute grade ≥2) can serve as a source of infection and are assigned a point in the CISNE score.
Monocyte Count

A low monocyte count (less than 200 cells/mm³) is indicative of a compromised immune system and is associated with a higher risk of complications, contributing a point.
Stress-Induced Hyperglycemia

Elevated blood sugar levels due to stress can negatively impact outcomes and are assigned two points in the CISNE score.

The total CISNE score ranges from 0 to 8, with each point reflecting an increased risk of serious complications.

Risk Stratification Using CISNE

The CISNE score stratifies patients into three distinct risk categories, guiding clinical decision-making:

CISNE Risk Categories

Risk Category	CISNE Score	Likelihood of Complications
Low Risk (Category I)	0	Approximately 1%
Intermediate Risk (Category II)	1 or 2	Approximately 6%
High Risk (Category III)	≥ 3	Approximately 36%

This stratification allows clinicians to identify patients who may be safely managed in an outpatient setting (typically low risk) versus those who require inpatient hospitalization and more intensive management (intermediate and high risk).

CISNE vs. MASCC Score

The MASCC (Multinational Association for Supportive Care in Cancer) score is another widely used risk stratification tool for febrile neutropenia. However, studies have shown that the CISNE score may have advantages, particularly in identifying low-risk patients with solid tumors in the emergency department setting.

Comparing Predictive Accuracy

While the MASCC score is known for its high sensitivity in identifying low-risk patients, it can have lower specificity, meaning it may classify some patients as low risk who are actually at higher risk of complications, especially those with solid tumors. The CISNE score, on the other hand, has demonstrated higher specificity in identifying truly low-risk patients, which is crucial for safely considering outpatient management or early discharge.

Research comparing the two scores in emergency departments has suggested that CISNE may be a more appropriate tool for risk-stratification in this setting due to its better specificity in identifying patients who are genuinely at low risk of adverse outcomes.

Clinical Application of the CISNE Score

The primary aim of using the CISNE score is to provide a greater degree of certainty about whether a patient's apparent stability is real. This information is vital for making informed decisions about the appropriate level of care, potentially preventing unnecessary hospitalizations for low-risk patients while ensuring that those at higher risk receive prompt inpatient management.

Guiding Treatment Strategies

For patients classified as low risk by the CISNE score (score of 0), outpatient management with oral antibiotics may be considered in some cases. However, it is important to note that the use of CISNE to select patients for outpatient care with oral antibiotics should ideally be supported by further clinical trials to confirm safety.

Patients in the intermediate (score of 1 or 2) and high-risk (score ≥ 3) categories typically require inpatient hospitalization for intravenous antibiotics and closer monitoring due to their increased risk of developing serious complications such as shock, respiratory failure, renal dysfunction, and other adverse events.

The CISNE score is particularly valuable in the emergency department, where rapid and accurate risk assessment is essential for guiding initial management decisions.

Diagram showing risk stratification for febrile neutropenia

Visual representation of risk stratification in febrile neutropenia.

Limitations and Considerations

While the CISNE score is a valuable tool, it's important to consider its limitations. It was primarily developed and validated for use in adult outpatients with solid tumors receiving mild/moderate intensity chemotherapy. Its applicability to other patient populations, such as those with hematologic malignancies or those receiving high-intensity chemotherapy, may vary.

Furthermore, risk scores should always be used in conjunction with clinical judgment. A patient's overall clinical presentation, comorbidities, and the availability of resources should also be taken into account when making management decisions, regardless of the CISNE score.

The CISNE score is designed to predict major complications and the need for hospitalization, but it should not be the sole determinant of whether a patient is discharged. Ongoing monitoring and assessment are crucial, especially for patients who are considered for outpatient management.

Frequently Asked Questions about the CISNE Score

What is the main purpose of the CISNE score?

The main purpose of the CISNE score is to help identify patients with febrile neutropenia who appear clinically stable but are at a higher risk of developing serious medical complications. This assists clinicians in making decisions about the appropriate level of care, such as whether to hospitalize the patient or consider outpatient management.

How is the CISNE score calculated?

The CISNE score is calculated by assigning points based on six clinical and laboratory variables: ECOG performance status (≥2 points), history of COPD (1 point), history of chronic cardiovascular disease (1 point), oral mucositis (grade ≥2, 1 point), monocyte count (<200/mm³, 1 point), and stress-induced hyperglycemia (2 points). The total score is the sum of the points from these variables.

How are the CISNE scores interpreted?

CISNE scores are interpreted by stratifying patients into risk categories: a score of 0 indicates low risk, a score of 1 or 2 indicates intermediate risk, and a score of 3 or higher indicates high risk of complications.

How does the CISNE score compare to the MASCC score?

While both CISNE and MASCC scores are used for risk stratification in febrile neutropenia, the CISNE score has shown higher specificity than the MASCC score in identifying truly low-risk patients, particularly those with solid tumors presenting to the emergency department. This means CISNE may be better at identifying patients who can be safely managed outside the hospital.

Can the CISNE score be used for all patients with febrile neutropenia?

The CISNE score was primarily developed and validated for adult outpatients with solid tumors receiving mild to moderate intensity chemotherapy. Its applicability to other patient groups, such as those with hematologic malignancies or receiving high-intensity chemotherapy, should be considered in the context of available research and clinical judgment.