Accelerated chronic lymphocytic leukemia - characteristics and retrospective analysis of the Polish Adult Leukemia Study Group.

Introduction: Accelerated chronic lymphocytic leukemia (A-CLL) is a rare histological variant of CLL, which is associated with an aggressive clinical presentation and worse prognosis. The aim was to study the characteristics and treatment outcomes of A-CLL patients.

Material and methods: The retrospective analysis included 106 A-CLL patients treated in Poland between 2013 and 2023.

Results: Median overall survival (OS) for treatment-naive A-CLL was 6.05 years (95% CI: 4.7-NA) and median progression-free survival (PFS) was 5.66 years (95% CI: 4.05-6.34). Factors associated with worse PFS were: Eastern Cooperative Oncology Group > 2 (p < 0.0001) and del17p (p = 0.002). In the whole group, fludarabine-based regimens improved OS (p = 0.002) and PFS (p = 0.002). This therapy proved superior to R-CHOP-like protocols for both OS (p = 0.002) and PFS (p = 0.004). The difference in survival between fludarabine-based regimens and targeted therapy was not significant. However, the group of patients treated with new therapies was very heterogeneous. Fludarabine (p = 0.004) or targeted therapy (p = 0.02) in any line of treatment during acceleration was associated with a reduced risk of death.

Conclusions: This study represents one of the largest datasets of A-CLL patients and shows its poorer prognosis compared to typical CLL. Chronic lymphocytic leukemia directed therapy should be considered as a treatment modality of choice for A-CLL. R-CHOP protocols are less effective.