Clinical and Prognostic Features of Essential Thrombocythemia: Comparison of 2001 WHO Versus 2008/2016 WHO Criteria in a Large Single-center Cohort.
CLINICAL LYMPHOMA, MYELOMA & LEUKEMIA 2021;
21:e328-e333. [PMID:
33342728 DOI:
10.1016/j.clml.2020.11.003]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/31/2020] [Accepted: 11/02/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND
According to 2008/2016 classification of the World Health Organization (WHO), a platelet (PLT) count ≥ 450 × 109/L, reduced from the previously published WHO 2001 indicated level ≥ 600 × 109/L, was considered the new PLT threshold for the diagnosis of essential thrombocythemia (ET).
PATIENTS AND METHODS
To validate this important diagnostic change in a setting of current clinical practice, we retrospectively analyzed clinical and hematologic features at diagnosis and during follow-up of 162 patients with ET, diagnosed in our center from January 2008 to December 2017. We subdivided patients according to PLT value at baseline into Group A (PLT ≥ 600 × 109/L) (124 patients; 76.5%) and Group B (PLT ≥ 450 × 109/L < 600 × 109/L) (38 patients; 23.5%).
RESULTS
Among clinical features, only the median value of leukocytes (P < .001) was significantly higher in Group A. Cytostatic treatment was administered in 103 patients, with a significantly higher rate in patients of group A (P < .001). After a median follow-up of 42.4 months (interquartile range, 22.1-70.6 months), 8 thrombotic events were recorded in the entire cohort, without differences between the 2 groups (P = .336). The 5-year overall survival (OS) of the entire cohort was 96.9% (95% confidence interval, 92.6%-100%), without differences between the 2 groups (P = .255).
CONCLUSIONS
Our data indicate a substantial homogeneity among patients with ET regardless of the PLT count at diagnosis, thus confirming the usefulness of the 2008/2016 WHO diagnostic criteria.
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