Table 2:
Risk stratification and response of children with ABL-class positive B-ALL
| Response criteria | Category | ABL-class | ABL1 | ABL2 | CSF1R | PDGFRB | Pearson χ2 | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| N (%) | N | N | N | N | |||||||
| 122 | 40 | 8 | 10 | 64 | |||||||
| Prednisone window response | PGR | 29 (51%) | 13 | 2 | 4 | 10 | |||||
| PPR | 28 (49%) | 1 | 3 | 0 | 24 | 0.00015* | |||||
| Treatment arm | non-HR | 28 (23%) | 16 | 1 | 4 | 7 | |||||
| HR | 93 (77%) | 23 | 7 | 6 | 57 | 0.0023* | |||||
| MRD EOI | negative | 5 (5%) | 3 | 0 | 1 | 1 | |||||
| <10−4, including positive not quantifiable | 11 (12%) | 8 | 0 | 3 | 0 | ||||||
| 10−4 to 10−2 | 16 (17%) | 9 | 1 | 1 | 5 | ||||||
| ≥10−2 | 61 (66%) | 9 | 6 | 3 | 43 | <0.0001* | |||||
| Type of events | no event, in CR | 72 (59%) | 27 | 3 | 8 | 34 | |||||
| total number of events | 50 (41%) | 13 | 5 | 2 | 30 | N/A** | |||||
| early death | 3 (2.5%) | 1 | 0 | 0 | 2 | ||||||
| non-responder | 3 (2.5%) | 0 | 0 | 0 | 3 | ||||||
| relapse | 35 (29%) | 12 | 2 | 2 | 19 | ||||||
| 2nd malignancy | 2 (1.5%) | 0 | 0 | 0 | 2 | ||||||
| death in 1st CR | 7 (6%) | 0 | 3 | 0 | 4 | ||||||
| HSCT in HR treated cases | no | 43 (51%) | 13 | 1 | 4 | 25 | |||||
| (landmark 6 months) | in CR | 25 (67%) | 8 | 0 | 3 | 14 | |||||
| relapse | 18 (33%) | 5 | 1 | 1 | 11 | ||||||
| yes | 41 (49%) | 8 | 2 | 2 | 29 | N/A** | |||||
| in 2nd CR | 25 (61%) | 4 | 1 | 1 | 19 | ||||||
| total number of events after HSCT | 16 (39%) | 4 | 1 | 1 | 10 | ||||||
| relapse | 7 (17%) | 1 | 1 | 1 | 4 | ||||||
| 2nd malignancy | 2 (5%) | 0 | 0 | 0 | 2 | ||||||
| treatment-related mortality | 7 (17%) | 3 | 0 | 0 | 4 | ||||||
PPR, prednisone poor response, defined by ≥1,000 blasts per μl of peripheral blood at day 8 of a therapeutic window with prednisone; PGR, prednisone good response, defined by <1,000 blasts per μl of peripheral blood at day 8. Percentage of cases in each category out of the total number of cases with registered information is given in parentheses. One exception: HSCT variable: the total number of patients in 2nd CR and those suffering from any event was set to 100%. Three non-responders (all PDGFRB fusion positive cases) also received HSCT, one relapsed, one suffered from treatment-related mortality and one achieved a 2nd CR. These 3 patients were included in the HSCT outcome analysis for whom time from landmark at 6 months to relapse, to death and last contact was used, respectively.
Pearson χ2 p-values are estimates because the number of cases is less than 5 for some variables.
N/A, Pearson χ2 not applicable since time-related occurrence of events. Number of patients with missing or no data: Prednisone window response 65; treatment arm 1; MRD EOI 29; HSCT 7.