Clinical features of pediatric B-precursor ALLs with 2 types of in vitro response to DNA DSBs
| Parameter . | Apoptosis-sensitive ALL (n = 47) . | Apoptosis-resistant ALL (n = 27) . | Difference between the 2 subgroups, P . |
|---|---|---|---|
| Clinical trial protocol, % (no.) | |||
| ALL97/99 | 38 (18/47) | 48 (13/27) | .468 |
| UKALL2003 | 62 (29/47) | 52 (14/27) | |
| Age at diagnosis ≥ 10 y | 9 (4/47) | 48 (13/27) | < .001 |
| WCC × 109, median (iqr) | 10.8 (6-49) | 10.6 (6-51) | .955 |
| Sex, % male (no.) | 55 (26/47) | 63 (17/27) | .627 |
| Initial risk classification, % (no.) | |||
| Low risk | 70 (33/47) | 44 (12/27) | .022 |
| Intermediate risk | 30 (14/47) | 52 (14/27) | |
| High risk | 0 (0/47) | 4 (1/27) | |
| Risk classification after early blast clearance, % (no.) | |||
| Low risk | 69 (31/45) | 41 (9/22) | .002 |
| Intermediate risk | 24 (11/45) | 18 (4/22) | |
| High risk | 7 (3/45) | 41 (9/227) | |
| Blast clearance at day 8/15, % (no.)* | 93 (41/44) GER 7 (3/44) PER | 62 (13/21) GER 38 (8/21) PER | .005 |
| Positive molecular MRD at day 28, % (no.)† | 19 (5/26) | 69 (9/13) | .004 |
| Positive FACS MRD at day 28, % (no.)† | 21 (8/38) | 59 (10/17) | .014 |
| Median follow-up, mo (range) | 40.0 (29.9-55.2) | 37.9 (22.8-53.1) | .475 |
| 3-y event-free survival, %‡ | 93.4 | 87.5 | .176 |
| Parameter . | Apoptosis-sensitive ALL (n = 47) . | Apoptosis-resistant ALL (n = 27) . | Difference between the 2 subgroups, P . |
|---|---|---|---|
| Clinical trial protocol, % (no.) | |||
| ALL97/99 | 38 (18/47) | 48 (13/27) | .468 |
| UKALL2003 | 62 (29/47) | 52 (14/27) | |
| Age at diagnosis ≥ 10 y | 9 (4/47) | 48 (13/27) | < .001 |
| WCC × 109, median (iqr) | 10.8 (6-49) | 10.6 (6-51) | .955 |
| Sex, % male (no.) | 55 (26/47) | 63 (17/27) | .627 |
| Initial risk classification, % (no.) | |||
| Low risk | 70 (33/47) | 44 (12/27) | .022 |
| Intermediate risk | 30 (14/47) | 52 (14/27) | |
| High risk | 0 (0/47) | 4 (1/27) | |
| Risk classification after early blast clearance, % (no.) | |||
| Low risk | 69 (31/45) | 41 (9/22) | .002 |
| Intermediate risk | 24 (11/45) | 18 (4/22) | |
| High risk | 7 (3/45) | 41 (9/227) | |
| Blast clearance at day 8/15, % (no.)* | 93 (41/44) GER 7 (3/44) PER | 62 (13/21) GER 38 (8/21) PER | .005 |
| Positive molecular MRD at day 28, % (no.)† | 19 (5/26) | 69 (9/13) | .004 |
| Positive FACS MRD at day 28, % (no.)† | 21 (8/38) | 59 (10/17) | .014 |
| Median follow-up, mo (range) | 40.0 (29.9-55.2) | 37.9 (22.8-53.1) | .475 |
| 3-y event-free survival, %‡ | 93.4 | 87.5 | .176 |
iqr indicates interquartile range; GER, good early response (ie, < 25% blasts at days 8/15 after start of induction therapy); and PER, poor early response (ie, ≥ 25% blasts at days 8/15). Significant P values are given in bold.
Assessment day depends on protocol—day 15 for initial low-risk patients, day 8 for intermediate-/high-risk patients.
Minimal residual disease as classified by both FACS and molecular analysis at day 28 after the start of induction therapy (positive, ≥ 0.01% leukemic blasts; negative, < 0.01% blasts).
Event indicates relapse or treatment-related death. A total of 3 relapses and 1 treatment-related death occurred in the apoptosis-sensitive group and 5 relapses in the apoptosis-resistant group.