ABSTRACT
PURPOSE: Comorbid medical conditions define a subset of patients with chronic lymphocytic leukemia (CLL) with poor outcomes. However, which comorbidities are most predictive remains understudied. EXPERIMENTAL DESIGN: We conducted a retrospective analysis from 10 academic centers to ascertain the relative importance of comorbidities assessed by the cumulative illness rating scale (CIRS). The influence of specific comorbidities on event-free survival (EFS) was assessed in this derivation dataset using random survival forests to construct a CLL-specific comorbidity index (CLL-CI). Cox models were then fit to this dataset and to a single-center, independent validation dataset. RESULTS: The derivation and validation sets comprised 570 patients (59% receiving Bruton tyrosine kinase inhibitor, BTKi) and 167 patients (50% receiving BTKi), respectively. Of the 14 CIRS organ systems, three had a strong and stable influence on EFS: any vascular, moderate/severe endocrine, moderate/severe upper gastrointestinal comorbidity. These were combined to create the CLL-CI score, which was categorized into 3 risk groups. In the derivation dataset, the median EFS values were 58, 33, and 20 months in the low, intermediate, and high-risk groups, correspondingly. Two-year overall survival (OS) rates were 96%, 91%, and 82%. In the validation dataset, median EFS values were 81, 40, and 23 months (two-year OS rates 97%/92%/88%), correspondingly. Adjusting for prognostic factors, CLL-CI was significantly associated with EFS in patients treated with either chemo-immunotherapy or with BTKi in each of our 2 datasets. CONCLUSIONS: The CLL-CI is a simplified, CLL-specific comorbidity index that can be easily applied in clinical practice and correlates with survival in CLL.
Subject(s)
Leukemia, Lymphocytic, Chronic, B-Cell/complications , Adult , Aged , Aged, 80 and over , Humans , Middle Aged , Progression-Free Survival , Proportional Hazards Models , Retrospective StudiesSubject(s)
Leukemia, Lymphocytic, Chronic, B-Cell/epidemiology , Adenine/analogs & derivatives , Area Under Curve , Female , Humans , Immunoglobulin Heavy Chains/genetics , In Situ Hybridization, Fluorescence , Incidence , Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/mortality , Male , Multicenter Studies as Topic , Piperidines , Prognosis , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/adverse effects , Protein Kinase Inhibitors/therapeutic use , Pyrazoles/administration & dosage , Pyrazoles/adverse effects , Pyrazoles/therapeutic use , Pyrimidines/administration & dosage , Pyrimidines/adverse effects , Pyrimidines/therapeutic use , Retrospective StudiesABSTRACT
BACKGROUND: Most patients with chronic lymphocytic leukemia (CLL) present with multiple comorbidities. Although comorbidities negatively affect outcomes for patients treated with chemoimmunotherapy, their impact on patients who receive targeted therapies is unknown. METHODS: This multicenter, retrospective analysis evaluated the significance of comorbidities, as assessed by the Cumulative Illness Rating Scale (CIRS), among patients with CLL treated with ibrutinib. RESULTS: One hundred forty-five patients received ibrutinib (80% in a relapsed/refractory setting). A high burden of comorbidities (CIRS score ≥ 7) was associated with inferior median event-free survival (EFS; 24 vs 37 months; P = .003) and 2-year overall survival (OS; 79% vs 100%; P = .005). In an adjusted Cox model, both EFS and OS worsened with an incremental increase in the CIRS score. Furthermore, comorbidities were associated with an increased risk of ibrutinib dose reduction and therapy discontinuation. CIRS was predictive in both frontline and relapsed CLL, regardless of patient age. CONCLUSIONS: Comorbidities portend a poor prognosis among patients with CLL treated with ibrutinib. Prospective studies are needed to optimize the treatment of patients with CLL who have comorbidities. Cancer 2018. © 2018 American Cancer Society.
