ABSTRACT
Cytogenetic lesions do not completely explain clinical heterogeneity of chronic lymphocytic leukemia (CLL). The 2016 revision of the World Health Organization classification 2008 indicated that molecular lesions of TP53, NOTCH1, SF3B1 and BIRC3 have potential clinical relevance and could be integrated into an updated risk profile. The negative clinical implications of TP53 disruptions are well constituted and patients with these mutations should be considered for novel, small molecule signal transduction inhibitors therapies. Mutations of NOTCH1, SF3B1 and BIRC3 are associated with poor prognosis. Patients with mutated SF3B1 or NOTCH1 genes present shorter time to first treatment compared to unmutated group. NOTCH1 mutations are related to a high risk of Richter's syndrome transformation, especially in case of TP53 disruptions' coexistence. Large studies on MYD88 mutations in CLL have not explained clearly their clinical importance.The aim of this paper is to provide a comprehensive review on novel molecular aberrations identified in CLL.
Subject(s)
Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis , ADP-ribosyl Cyclase 1/genetics , Computers, Molecular , Humans , Immunoglobulin alpha-Chains/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/physiopathology , Mutation , Prognosis , ZAP-70 Protein-Tyrosine Kinase/geneticsABSTRACT
INTRODUCTION Currently available prognostic factors determining the course of chronic lymphocytic leukemia (CLL) are not fully efficient, especially for newly diagnosed patients. Investigation of molecular changes may help clarify the reasons for the heterogeneity of the disease. Apart from already confirmed TP53 mutations, the novel candidates: NOTCH1, SF3B1, and MYD88 might represent clinically relevant biomarkers. OBJECTIVES The aim of this study was to evaluate the mutational status of NOTCH1, MYD88, and SF3B1 and to compare the results with confirmed prognostic factors: ZAP70, CD38, and immunoglobulin heavychain variable region (IGHV) mutation in CLL. The study assessed also prognostic significance in terms of the time to first treatment (TTFT) and subset analysis. PATIENTS AND METHODS The study was conducted on samples of 370 newly diagnosed patients with CLL. The analysis was performed using highresolution melting, Sanger sequencing, and polymerase chain reaction methods. RESULTS Patients harboring the NOTCH1 mutation were significantly more often found among patients with an unmutated IGHV gene status and high expression of CD38 and ZAP70. The MYD88 mutation was equally distributed in patients with mutated and unmutated IGHV status (5 vs 7 patients). For MYD88 and SF3B1, there were no significant differences in the levels of CD38 and ZAP70 expression. The tendency for lower median TTFT was revealed in patients with mutated SF3B1 (P = 0.08). The analysis showed the presence of 14 different types of the subsets of IGHV in 50 of 345 patients (14.5%). The most frequent were subsets #1 and #2. CONCLUSIONS The NOTCH1 and SF3B1 mutations accompany biological markers of unfavorable prognosis in patients with CLL. The mutations may contribute to the identification of patients with highrisk CLL.
