Comparisons of clinical characteristics, molecular features, and outcomes of older primary CN-AML patients with and without FLT3-ITD
| Characteristic . | FLT3-ITD (n = 72) . | FLT3-WT (n = 147) . | P . |
|---|---|---|---|
| Age, y | .92 | ||
| Median | 68 | 69 | |
| Range | 60-81 | 60-83 | |
| Age group, n (%) | .67 | ||
| 60-69 y | 41 (57) | 78 (53) | |
| ≥ 70 y | 31 (43) | 69 (47) | |
| Sex, no. of males (%) | 36 (50) | 75 (51) | 1.00 |
| Race, n (%) | .81 | ||
| White | 66 (92) | 129 (90) | |
| Nonwhite | 6 (8) | 14 (10) | |
| Protocol,* n (%) | |||
| 8525 | 11 (15) | 10 (7) | |
| 8923 | 9 (13) | 9 (6) | |
| 9420 | 3 (4) | 3 (2) | |
| 9720 | 27 (38) | 75 (51) | |
| 10201 | 22 (31) | 50 (34) | |
| Hemoglobin, g/dL | .35 | ||
| Median | 9.7 | 9.4 | |
| Range | 6.0-15.0 | 6.0-13.1 | |
| Platelet count, ×109/L | .40 | ||
| Median | 60 | 72 | |
| Range | 4-850 | 5-510 | |
| WBC, ×109/L | < .001 | ||
| Median | 47.1 | 10.4 | |
| Range | 0.9-450.0 | 0.9-198.0 | |
| Blood blasts, % | < .001 | ||
| Median | 70 | 24 | |
| Range | 0-99 | 0-96 | |
| Bone marrow blasts, % | < .001 | ||
| Median | 82 | 57 | |
| Range | 7-97 | 7-96 | |
| Centrally reviewed FAB classification, n (%) | |||
| M0 | 0 (0) | 4 (5) | |
| M1 | 17 (35) | 11 (13) | |
| M2 | 9 (18) | 31 (36) | |
| M4 | 12 (24) | 22 (26) | |
| M5 | 11 (22) | 12 (14) | |
| M6 | 0 (0) | 5 (6) | |
| Extramedullary involvement, n (%) | 20 (29) | 23 (16) | .04† |
| NPM1, n (%) | < .001 | ||
| Mutated | 53 (74) | 68 (46) | |
| Wild-type | 19 (26) | 79 (54) | |
| WT1, n (%) | .001 | ||
| Mutated | 11 (15) | 4 (3) | |
| Wild-type | 61 (85) | 143 (97) | |
| CEBPA, n (%) | .53 | ||
| Mutated | 11 (15) | 18 (12) | |
| Wild-type | 61 (85) | 129 (88) | |
| MLL-PTD, n (%) | .50 | ||
| Positive | 2 (4) | 8 (7) | |
| Negative | 53 (96) | 104 (93) | |
| IDH1, n (%) | .25 | ||
| Mutated | 5 (9) | 21 (17) | |
| Wild-type | 50 (91) | 102 (83) | |
| IDH2, n (%) | .02 | ||
| Mutated, R140 IDH2 | 8 (15) | 29 (24) | (IDH2-mutated vs IDH2-WT) |
| Mutated, R172 IDH2 | 0 (0) | 10 (8) | |
| Wild-type | 47 (85) | 84 (68) | |
| Outcome for all patients, no. | 72 | 147 | |
| Complete remission rate, n (%) | 48 (67) | 103 (70) | .64 |
| Disease-free survival | .007 | ||
| Median, y | 0.5 | 1.0 | |
| Disease-free at 3 y, % (95% CI) | 10 (4-21) | 18 (12-26) | |
| Overall survival | < .001 | ||
| Median, y | 0.8 | 1.4 | |
| Alive at 3 y, % (95% CI) | 14 (7-23) | 23 (16-30) | |
| Outcome for patients aged 60-69 y, no. | 41 | 78 | |
| Complete remission rate, no. (%) | 29 (71) | 58 (75) | .67 |
| Disease-free survival | < .001 | ||
| Median, y | 0.4 | 1.0 | |
| Disease-free at 3 y, % (95% CI) | 7 (1-20) | 19 (10-30) | |
| Overall survival | < .001 | ||
| Median, y | 0.6 | 1.4 | |
| Alive at 3 y, % (95% CI) | 10 (3–21) | 26 (16–36) | |
| Outcome for patients age ≥ 70 y, no. | 31 | 69 | |
| Complete remission rate, no. (%) | 19 (61) | 45 (65) | .82 |
| Disease-free survival | .94 | ||
| Median, y | 0.9 | 1.0 | |
| Disease-free at 3 y, % (95% CI) | 16 (4-35) | 18 (8-30) | |
| Overall survival | .71 | ||
| Median, y | 0.9 | 1.3 | |
| Alive at 3 y, % (95% CI) | 19 (8-35) | 20 (11-30) |
| Characteristic . | FLT3-ITD (n = 72) . | FLT3-WT (n = 147) . | P . |
|---|---|---|---|
| Age, y | .92 | ||
| Median | 68 | 69 | |
| Range | 60-81 | 60-83 | |
| Age group, n (%) | .67 | ||
| 60-69 y | 41 (57) | 78 (53) | |
| ≥ 70 y | 31 (43) | 69 (47) | |
| Sex, no. of males (%) | 36 (50) | 75 (51) | 1.00 |
| Race, n (%) | .81 | ||
| White | 66 (92) | 129 (90) | |
| Nonwhite | 6 (8) | 14 (10) | |
| Protocol,* n (%) | |||
| 8525 | 11 (15) | 10 (7) | |
| 8923 | 9 (13) | 9 (6) | |
| 9420 | 3 (4) | 3 (2) | |
| 9720 | 27 (38) | 75 (51) | |
| 10201 | 22 (31) | 50 (34) | |
| Hemoglobin, g/dL | .35 | ||
| Median | 9.7 | 9.4 | |
| Range | 6.0-15.0 | 6.0-13.1 | |
| Platelet count, ×109/L | .40 | ||
| Median | 60 | 72 | |
| Range | 4-850 | 5-510 | |
| WBC, ×109/L | < .001 | ||
| Median | 47.1 | 10.4 | |
| Range | 0.9-450.0 | 0.9-198.0 | |
| Blood blasts, % | < .001 | ||
| Median | 70 | 24 | |
| Range | 0-99 | 0-96 | |
| Bone marrow blasts, % | < .001 | ||
| Median | 82 | 57 | |
| Range | 7-97 | 7-96 | |
| Centrally reviewed FAB classification, n (%) | |||
| M0 | 0 (0) | 4 (5) | |
| M1 | 17 (35) | 11 (13) | |
| M2 | 9 (18) | 31 (36) | |
| M4 | 12 (24) | 22 (26) | |
| M5 | 11 (22) | 12 (14) | |
| M6 | 0 (0) | 5 (6) | |
| Extramedullary involvement, n (%) | 20 (29) | 23 (16) | .04† |
| NPM1, n (%) | < .001 | ||
| Mutated | 53 (74) | 68 (46) | |
| Wild-type | 19 (26) | 79 (54) | |
| WT1, n (%) | .001 | ||
| Mutated | 11 (15) | 4 (3) | |
| Wild-type | 61 (85) | 143 (97) | |
| CEBPA, n (%) | .53 | ||
| Mutated | 11 (15) | 18 (12) | |
| Wild-type | 61 (85) | 129 (88) | |
| MLL-PTD, n (%) | .50 | ||
| Positive | 2 (4) | 8 (7) | |
| Negative | 53 (96) | 104 (93) | |
| IDH1, n (%) | .25 | ||
| Mutated | 5 (9) | 21 (17) | |
| Wild-type | 50 (91) | 102 (83) | |
| IDH2, n (%) | .02 | ||
| Mutated, R140 IDH2 | 8 (15) | 29 (24) | (IDH2-mutated vs IDH2-WT) |
| Mutated, R172 IDH2 | 0 (0) | 10 (8) | |
| Wild-type | 47 (85) | 84 (68) | |
| Outcome for all patients, no. | 72 | 147 | |
| Complete remission rate, n (%) | 48 (67) | 103 (70) | .64 |
| Disease-free survival | .007 | ||
| Median, y | 0.5 | 1.0 | |
| Disease-free at 3 y, % (95% CI) | 10 (4-21) | 18 (12-26) | |
| Overall survival | < .001 | ||
| Median, y | 0.8 | 1.4 | |
| Alive at 3 y, % (95% CI) | 14 (7-23) | 23 (16-30) | |
| Outcome for patients aged 60-69 y, no. | 41 | 78 | |
| Complete remission rate, no. (%) | 29 (71) | 58 (75) | .67 |
| Disease-free survival | < .001 | ||
| Median, y | 0.4 | 1.0 | |
| Disease-free at 3 y, % (95% CI) | 7 (1-20) | 19 (10-30) | |
| Overall survival | < .001 | ||
| Median, y | 0.6 | 1.4 | |
| Alive at 3 y, % (95% CI) | 10 (3–21) | 26 (16–36) | |
| Outcome for patients age ≥ 70 y, no. | 31 | 69 | |
| Complete remission rate, no. (%) | 19 (61) | 45 (65) | .82 |
| Disease-free survival | .94 | ||
| Median, y | 0.9 | 1.0 | |
| Disease-free at 3 y, % (95% CI) | 16 (4-35) | 18 (8-30) | |
| Overall survival | .71 | ||
| Median, y | 0.9 | 1.3 | |
| Alive at 3 y, % (95% CI) | 19 (8-35) | 20 (11-30) |
WBC indicates white blood count; FAB, French-American-British classification; FLT3-ITD, internal tandem duplication of the FLT3 gene; WT, wild-type; and MLL-PTD, partial tandem duplication of the MLL gene.
Cancer and Leukemia Group B frontline treatment protocol received. See supplemental material for details.
FLT3-ITD patients tended to have more extramedullary involvement, particularly in terms of gum hypertrophy and lymphadenopathy.
Median follow-up was 3.8 years (range, 2.3-11.6) for patients alive.
FLT3-ITD indicates internal tandem duplication of the FLT3 gene; WT, wild-type; and CI, confidence interval.