The Chronic Lymphocytic Leukemia Comorbidity Index (CLL-CI): A Three-Factor Comorbidity Model.

Area of Science:

• Hematology
• Oncology
• Clinical Medicine

Background:

• Comorbidities significantly impact outcomes in chronic lymphocytic leukemia (CLL).
• Identifying the most predictive comorbidities for CLL patients remains an area needing further research.
• Existing comorbidity assessments may not be specific enough for CLL prognosis.

Purpose of the Study:

• To determine the relative importance of comorbidities in predicting outcomes for chronic lymphocytic leukemia (CLL) patients.
• To develop and validate a CLL-specific comorbidity index (CLL-CI) using the Cumulative Illness Rating Scale (CIRS).
• To assess the association of the CLL-CI with event-free survival (EFS) and overall survival (OS) in CLL.

Main Methods:

• Retrospective analysis of 570 patients from 10 academic centers (derivation set) and 167 patients (validation set).
• Utilized random survival forests to identify key comorbidities influencing EFS.
• Developed the CLL-CI score based on vascular, endocrine, and upper gastrointestinal comorbidities and validated using Cox models.

Main Results:

• Vascular, moderate/severe endocrine, and moderate/severe upper gastrointestinal comorbidities were strongly associated with EFS.
• The CLL-CI categorized patients into low, intermediate, and high-risk groups, showing distinct median EFS and two-year OS rates in both datasets.
• The CLL-CI demonstrated significant association with EFS in CLL patients treated with chemo-immunotherapy or Bruton tyrosine kinase inhibitors (BTKi).

Conclusions:

• The CLL-CI is a simplified, CLL-specific comorbidity index.
• The CLL-CI can be readily applied in clinical practice.
• The CLL-CI correlates with survival outcomes in patients with chronic lymphocytic leukemia.