Table 2.
Characteristics of the cytogenetic low-risk group according to DNA methylation/hydroxymethylation levels
| CLL patients with del(13q) | ||||||
|---|---|---|---|---|---|---|
| 5-mCyt low (n = 12) | 5-mCyt high (n = 18) | Statistics (p) | 5-hmCyt low (n = 15) | 5-hmCyt high (n = 15) | Statistics (p) | |
| Age at diagnosis, mean (±SD) | 65.8 (± 8.5) | 61.4 (± 8.0) | NS | 66.2 (± 8.6) | 60.2 (± 7.2) | NS |
| Age at study entry, mean (±SD) | 69.8 (± 7.6) | 67.2 (± 8.4) | NS | 69.6 (± 8.4) | 66.9 (± 7.7) | NS |
| Binet stage, No. of patients (%) | 0.02 | NS | ||||
| A | 6/12 (50%) | 16/18 (88.9%) | 9/15 (60%) | 12/15 (80%) | ||
| B/C | 6/12 (50%) | 2/18 (11.1%) | 6/15 (40%) | 3/15 (20%) | ||
| Lymphocytosis (Giga/L), mean (±SD) | 53.53 (± 38.30) | 33.93 (± 19.9) | NS | 34.6 (± 28.6) | 48.9 (± 30.0) | NS |
| IGHV status, No. of patients (%) | NS | NS | ||||
| Unmutated (≥ 98% homology) | 1/7 (14.3%) | 0/12 (0%) | 1/9 (11.1%) | 0/10 (0%) | ||
| Mutated (< 98% homology) | 6/7 (85.7%) | 12/12 (100%) | 8/9 (88.9%) | 10/10 (100%) | ||
| CD38 > 30%, No. of patients (%) | 5/12 (41.7%) | 4/16 (25%) | NS | 6/15 (40%) | 3/13 (23%) | NS |
| del(13q), > 80% nuclei (%) | 7/12 (58.3%) | 3/18 (16.7%) | 0.02 | 4/15 (26.7%) | 6/15 (40%) | NS |
| del(13q), biallelic | 4/12 (33.3%) | 12/18 (66.7%) | NS | 6/15 (40%) | 10/15 (66.7%) | NS |
| LDT from diagnosis, median (months)a | 12 | 36 | NS | 24 | 18 | NS |
| PFS, median (months)a | 44.5 | 120 | 0.01 | 56 | > 120 | 0.02 |
| TFS, median (months)a | 45 | > 120 | 0.0008 | 63 | > 120 | 0.04 |
Abbreviations: 5-mCyt 5-methylcytosine, 5-hmCyt 5-hydroxymethylcytosine, NS not significant, No. number, SD standard deviation, IGHV immunoglobulin heavy-chain variable region, LDT lymphocyte doubling time, PFS progression-free survival, TFS treatment-free survival, del deletion
aKaplan–Meier survival analysis