Table 3.
Characteristics of APL according to FLT3 mutations (ITD/DTK).
| Total*, n (%) | FLT3mut, n (%) | FLT3wt, n (%) | p | |
|---|---|---|---|---|
| Median age at diagnosis (years) | 10.1 | 11.2 | 9.5 | 0.197 |
| Age strata (years) | 0.087 | |||
| ≤ 2 | 8 (4.9) | 0 (0.0) | 5 (7.4) | |
| >2–10 | 71 (43.6) | 21 (40.4) | 31 (45.6) | |
| ≥11 | 84 (51.5) | 31 (59.6) | 32 (47.1) | |
| Sex | 0.292 | |||
| Females | 73 (44.8) | 18 (34.6) | 30 (44.1) | |
| Males | 90 (55.2) | 34 (65.4) | 38 (55.9) | |
| Race | 1.000 | |||
| Blacks | 16 (10.6) | 5 (10.4) | 6 (9.7) | |
| Non-Blacks | 135 (89.4) | 43 (89.6) | 56 (90.3) | |
| Median WBC count (× 109/L) | 13 | 31 | 7.1 | 0.002 |
| WBC count at diagnosis (× 109/L) | 0.001 | |||
| ≤ 10 | 74 (46.8) | 14 (27.5) | 39 (59.1) | |
| >10 | 84 (53.2) | 37 (72.6) | 27 (40.9) | |
| Platelet, median (× 109/L) | 22,500 | 21,000 | 30,500 | 0.118 |
| Platelet (× 109/L) | 0.011 | |||
| ≤ 40 | 105 (70.0) | 39 (83.0) | 40 (60.6) | |
| >40 | 45 (30.0) | 8 (17.0) | 26 (39.4) | |
| Morphologic subtype | 0.028 | |||
| Hypergranular | 141 (86.5) | 41 (78.8) | 63 (92.6) | |
| Microgranular | 22 (13.5) | 11 (21.2) | 5 (7.4) | |
| PML breakpoint region | <0.0001 | |||
| Bcr 1 | 18 (34.0) | 2 (9.5) | 13 (59.1) | |
| Bcr 2 | 2 (9.4) | 0 (0.0) | 4 (18.2) | |
| Bcr 3 | 3 (30.0) | 19 (90.5) | 5 (22.7) | |
| RAS MUTATIONS | 0.702 | |||
| Mutated | 11 (9.1) | 2 (5.1) | 5 (8.2) | |
| Wild-type | 110 (90.9) | 37 (94.9) | 56 (91.8) | |
| GSTT1 polymorphism | 0.556 | |||
| Non-null | 77 (67.0) | 25 (64.1) | 35 (70.0) | |
| Null | 38 (33.0) | 14 (35.9) | 15 (30.0) | |
| GSTM1 polymorphism | 0.969 | |||
| Non-null | 66 (57.4) | 22 (56.4) | 28 (56.0) | |
| Null | 49 (42.6) | 17 (43.6) | 22 (44.0) | |
| Early death** | 0.003 | |||
| Yes | 24 (17.6) | 22 (47.8) | 12 (20.7) | |
| No | 112 (82.4) | 24 (52.2) | 46 (79.3) | |
| Total | 163 (100) | 52/120 (43.0) | 69120 (57.0) |
*
We investigated 120 cases for FLT3 mutations.
**
Death in the first 10 days after diagnosis. Survival data were available from 136 patients. Mut, mutated (internal tandem duplications (ITDs) and tyrosine kinase domain (TKD) in codon 835); n, number of cases; WBC, white blood cell; wt, wild-type. All p-values were calculated using valid data and considered to be significant if < 0.05.