Last update:
02-Aug-2018

OBJECTIVE To assess the frequency of chromosomal aberrations with prognostic significance in a group of 116 previously untreated patients with chronic lymphocytic leukemia (CLL), and to perform risk stratification and compare survival times and time to first treatment (TTFT) between risk groups.

METHOD Four prognostic groups were formed, based on genetic abnormalities detected by FISH: low risk (del13q), intermediate risk (12q trisomy and no FISH abnormalities), high risk (del11q) and very high risk (del17p). Median overall survival (OS), progression-free survival (PFS) and time to first treatment (TTFT) were assessed for each group using the Kaplan-Meier method and comparisons were made by log-rank test. Within the del13q group survival times and TTFT were compared according to the presence of monoallelic, biallelic deletion or both, and the percentаge of cells with the abnormality (≥80% or <80%).

RESULTS Significant differences were found in the median OS, PFS and TTFT between the four groups, the patients with del17p having the worst prognosis. No significant difference was found in median OS and TTFT between the subgroups of patients with del13q (heterozygous vs homozygous deletions or the percentage of nuclei with the abnormality), but a higher percentage of del13q nuclei was associated with significantly shorter PFS.

CONCLUSIONS In this analysis, unlike previous studies, patients in the low-risk and intermediate-risk groups had a similar prognosis and may all be considered low-risk. The high-risk patients with del11q may have a better (intermediate) prognosis when treated with immunochemotherapy. These results confirm that patients with CLL bearing del17p should be considered very high risk and are candidates for treatment with novel agents or participation in clinical trials.

Key words: Chronic lymphocytic leukemia, FISH, Risk stratification, Survival.