Can Cytogenetic Markers Accurately Reflect Clinical Heterogeneity in CLL?
Posted: Wednesday, March 3, 2021
Found in more than half of patients with chronic lymphocytic leukemia (CLL), the chromosomal deletion 13q14 (del[13q]) is the most common cytogenetic abnormality. It may also serve as a prognostic factor when detected using fluorescent in situ hybridization (FISH). However, Beyhan Durak Aras, PhD, of the University of Eskisehir Osmangazi, Turkey, and colleagues reported that questions remain on why patients with CLL and del(13q) experience such variable clinical courses, though some researchers argue that type II deletions tend to be associated with a more aggressive disease course. The report, published in Molecular Cytogenetics, supported previous evidence that deletion burden has a prognostic effect. Still, the data do not confirm that type II deletion or biallelic deletion result in a poor prognosis.
The study team investigated the mechanisms behind clinical heterogeneity among 68 patients with CLL and del(13q). Peripheral blood samples were tested using FISH to determine RB1 deletion or type II status. The analyses included the effect of RB1 gene deletion, deletion burden, and deletion type on overall survival, disease stage, and time to first treatment.
The type II deletion, or RB1 gene, was observed in 41% of patients. However, no statistically significant relationship was found between RB1 gene deletion and disease stage, treatment status, β2 microglobulin levels, or the time to first treatment. Yet, the data indicated there might be a significant relationship between high del(13q) rates (> 80%) and time to first treatment (P < .05). The time to start treatment was significantly shorter in patients with a deletion rate higher than 80% compared with patients with a deletion rate lower than 80%.
“Further studies with larger case series are needed to clarify the cause of this heterogeneity,” the study team concluded.
Disclosure: The study authors reported no conflicts of interest.
