Epidemiology and prognostic nomogram for chronic eosinophilic leukemia: a population-based study using the SEER database

Abstract

Chronic Eosinophilic Leukemia (CEL), a rare and intricate hematological disorder characterized by uncontrolled eosinophilic proliferation, presents clinical challenges owing to its infrequency. This study aimed to investigate epidemiology and develop a prognostic nomogram for CEL patients. Utilizing the Surveillance, Epidemiology and End Results database, CEL cases diagnosed between 2001 and 2020 were analyzed for incidence rates, clinical profiles, and survival outcomes. Patients were randomly divided into training and validation cohorts (7:3 ratio). LASSO regression analysis and Cox regression analysis were performed to screen the prognostic factors for overall survival. A nomogram was then constructed and validated to predict the 3- and 5-year overall survival probability of CEL patients by incorporating these factors. The incidence rate of CEL was very low, with an average of 0.033 per 100,000 person-years from 2001 to 2020. The incidence rate significantly increased with age and was higher in males than females. The mean age at diagnosis was 57 years. Prognostic analysis identified advanced age, specific marital statuses, and secondary CEL as independent and adverse predictors of overall survival. To facilitate personalized prognostication, a nomogram was developed incorporating these factors, demonstrating good calibration and discrimination. Risk stratification using the nomogram effectively differentiated patients into low- and high-risk groups. This study enhances our understanding of CEL, offering novel insights into its epidemiology, demographics, and prognostic determinants, while providing a possible prognostication tool for clinical use. However, further research is warranted to elucidate molecular mechanisms and optimize therapeutic strategies for CEL.

Keywords: Chronic eosinophilic leukemia; Epidemiology; Incidence; Nomogram; SEER.

Figure 1

Age-adjusted incidence of CEL from 2001 to 2020 in SEER database. (A) Annual age-adjusted incidence of CEL; (B) Age-adjusted incidence of CEL based on age of diagnosis; (C) Annual age-adjusted incidence of CEL in male and female populations, respectively; (D) Age-adjusted incidence of CEL based on age of diagnosis in male and female patients, respectively. CEL, chronic eosinophilic leukemia.

Figure 2

Flow chart of study cohort selection using the SEER database. A flow diagram of selection of patients with CEL in this study. CEL, chronic eosinophilic leukemia; SEER, Surveillance, Epidemiology, and End Results.

Figure 3

LASSO regression model was used to select characteristic impact factors. (A) LASSO coefficients of 7 features; (B) Selection of tuning parameter (λ) for LASSO model.

Figure 4

Construction of the prognostic nomogram of CEL patients based on 3 risk factors. The total points were calculated by integrating scores related to age, marital status, sequence and projected to the bottom scale to predict the overall survival probability at 3 and 5 years. CEL, chronic eosinophilic leukemia.

Figure 5

Evaluation of the nomogram of by calibration plot. (A) The calibration curve of the training set for the observed overall survival (OS) probability and predicted OS at 3-year and 5-year. (B) The calibration curve of the validation set at 3-year and 5-year.

Figure 6

Evaluation of the nomogram of by receiver operating characteristic (ROC) plot. (A) Time-dependent ROC curve analyses of the nomograms for the 3 years and 5 years in the training set. (B) Time-dependent ROC curve analyses of the validation set.

Figure 7

Evaluation of the nomogram of by decision curve analyses. (A, B) The decision curve analyses of the nomogram for the 3 years (A) and 5 years (B) in the training set. (C, D) The decision curve analysis of the nomogram for the 3 years (C) and 5 years (D) in the validation set.

Figure 8

Kaplan–Meier curve of overall survival of CEL patients stratified by the risk stratification system in the training set (A) and validation set (B). CEL, chronic eosinophilic leukemia.