Table 1.
Clinical and laboratory characteristics, at time of initial diagnosis of primary myelofibrosis, of 1306 patients, stratified by whether or not they developed leukemic transformation during their clinical course
| Variables | All patients (n = 1306) | Patients who transformed into acute myeloid leukemia during their clinical course (n = 149) | Patients who remained in chronic phase disease at last follow-up (n = 1157) | P value |
|---|---|---|---|---|
| Age in years; median (range) | 65 (19–92) | 64 (32–85) | 65 (19–92) | 0.2 |
| Age > 70 years; n (%) | 382 (29) | 35 (23) | 347 (30) | 0.1 |
| Males; n (%) | 820 (63) | 106 (71) | 714 (62) | 0.02 |
| Hemoglobin, g/dl; median (range) “N” evaluable = 1298 | 10.2 (3.8–17.5) | 10.2 (6.1–15.2) | 10.3 (3.8–17.5) | 0.7 |
| Hemoglobin < 10 g/dl; n (%) “N” evaluable = 1298 | 608 (47) | 69 (48) | 539 (47) | 0.8 |
| Sex and severity adjusted anemia categories | 0.6 | |||
| “N” evaluable = 1298 | ||||
| Mild/no anemia; n (%) | 591 (46) | 63 (44) | 528 (46) | |
| Moderate/severe anemia; n (%) | 707 (54) | 81 (56) | 626 (54) | |
| Transfusion dependent; n (%) “N” evaluable = 1299 | 417 (32) | 38 (26) | 379 (33) | 0.1 |
| Platelets, ×109/l; median (range) “N” evaluable = 1299 | 225 (6–2400) | 202 (10–2399) | 230 (6–2400) | 0.09 |
| Platelets < 100 × 109/l; n (%) “N” evaluable = 1299 | 294 (23) | 38 (26) | 256 (22) | 0.2 |
| Leukocytes, ×109/l; median (range) “N” evaluable = 1298 | 8.8 (0.8–249) | 10 (1.1–249) | 8.8 (0.8–236) | 0.5 |
| Leukocytes > 25 × 109/l; n (%) “N” evaluable = 1298 | 189 (15) | 23 (16) | 166 (14) | 0.6 |
| Circulating blasts %; median (range) “N” evaluable = 1283 | 0 (0–18) | 1 (0–18) | 0 (0–18) | 0.03 |
| Circulating blasts ≥ 3%; n (%) “N” evaluable = 1283 | 217 (17) | 34 (24) | 183 (16) | 0.02 |
| Palpable splenomegaly; n (%) “N” evaluable = 1260 | 902 (72) | 94 (70) | 808 (72) | 0.6 |
| Bone marrow fibrosis grade (2 or above); n (%) “N” evaluable = 793 | 646 (81) | 82 (79) | 564 (82) | 0.4 |
| Constitutional symptoms; n (%) “N” evaluable = 1302 | 375 (29) | 45 (31) | 330 (29) | 0.5 |
| History of any thrombosis at or prior to diagnosis; n (%) “N” evaluable = 1299 | 208 (16) | 15 (11) | 193 (17) | 0.05 |
| History of venous thrombosis at or prior to diagnosis; n (%) “N” evaluable = 1298 | 92 (7) | 5 (4) | 87 (8) | 0.08 |
| History of arterial thrombosis at or prior to diagnosis; n (%) “N” evaluable = 1299 | 136 (10) | 12 (8) | 124 (11) | 0.4 |
| Karyotype | 0.2 | |||
| “N” evaluable = 1218 | ||||
| Favorable; n (%) | 931 (76) | 91 (71) | 840 (77) | |
| Unfavorable; n (%) | 212 (17) | 26 (20) | 186 (17) | |
| VHR; n (%) | 75 (6) | 12 (9) | 63 (6) | |
| DIPSS risk stratification | 0.005 | |||
| “N” evaluable = 1265 | ||||
| High risk; n (%) | 111 (9) | 7 (6) | 104 (9) | |
| Intermediate risk-2; n (%) | 501 (39) | 50 (42) | 451 (39) | |
| Intermediate risk-1; n (%) | 466 (37) | 54 (46) | 412 (36) | |
| Low risk; n (%) | 187 (15) | 7 (6) | 180 (16) | |
| GIPSS risk stratification | 0.07 | |||
| “N” evaluable = 560 | ||||
| High risk; n (%) | 142 (25) | 21 (29) | 121 (25) | |
| Intermediate risk-2; n (%) | 169 (30) | 29 (40) | 140 (29) | |
| Intermediate risk-1; n (%) | 198 (35) | 18 (25) | 180 (37) | |
| Low risk; n (%) | 51 (9) | 4 (6) | 47 (10) | |
| MIPSS70 + version 2.0 risk stratification | 0.02 | |||
| “N” evaluable = 513 | ||||
| Very high risk; n (%) | 104 (20) | 15 (17) | 89 (21) | |
| High risk; n (%) | 209 (41) | 49 (56) | 160 (38) | |
| Intermediate risk; n (%) | 97 (19) | 9 (10) | 88 (21) | |
| Low risk; n (%) | 80 (16) | 13 (15) | 67 (16) | |
| Very low risk; n (%) | 23 (4) | 2 (2) | 21 (5) | |
| Driver mutational status | 0.06 | |||
| “N” evaluable = 897 | ||||
| JAK2; n (%) | 603 (67) | 48 (54) | 555 (69) | |
| CALR type 1/like; n (%) | 149 (16) | 18 (20) | 121 (15) | |
| CALR type 2/like; n (%) | 31 (3) | 4 (4) | 27 (3) | |
| MPL; n (%) | 54 (6) | 7 (8) | 47 (6) | |
| Triple-negative; n (%) | 70 (8) | 12 (13) | 58 (7) | |
| ASXL1 mutated; n (%) “N” evaluable = 596 | 246 (41) | 41 (55) | 205 (39) | 0.01 |
| SRSF2 mutated; n (%) “N” evaluable = 597 | 83 (14) | 21 (27) | 62 (12) | 0.001 |
| IDH1 mutated; n (%) “N” evaluable = 479 | 9 (2) | 4 (6) | 5 (1) | 0.02 |
| IDH2 mutated; n (%) “N” evaluable = 479 | 18 (4) | 5 (8) | 13 (3) | 0.07 |
| EZH2 mutated; n (%) “N” evaluable = 452 | 17 (4) | 2 (3) | 15 (4) | 0.9 |
| U2AF1 mutated; n (%) “N” evaluable = 579 | 88 (15) | 11 (15) | 77 (15) | 0.9 |
| U2AF1 Q157 mutated; n (%) “N” evaluable = 579 | 57 (10) | 6 (8) | 51 (10) | 0.8 |
| Allogeneic stem cell transplant; n (%) | 68 (6) | 4 (3) | 64 (6) | 0.2 |
| Follow-up in years; median (range) | 3.2 (0–31) | 3.1 (0.3–20.2) | 3.2 (0–31) | 0.9 |
| Deaths; n (%) | 922 (71) | 142 (95) | 780 (67) | <0.0001 |
DIPSS dynamic international prognostic scoring system, GIPSS genetically-inspired prognostic scoring system, MIPSS70 + Version 2.0 mutation-enhanced international prognostic scoring system, VHR very high-risk karyotype
Bold values indicates significance indicator