Patient characteristics at diagnosis and postdiagnosis rates of major thrombosis and hemorrhage in young patients with ET (aged < 60 years) and extreme thrombocytosis (platelet count ≥ 1000 × 109/L) who presented without thrombohemorrhagic complications, stratified by the use or not of prophylactic cytoreductive therapy
. | Entire cohort . | Patients receiving prophylactic cytoreductive therapy . | Patients not receiving prophylactic cytoreductive therapy . | P . |
|---|---|---|---|---|
| No. patients | 99 | 75 | 24 | |
| Median age, y (range) | 43 (16-59) | 45 (16-59) | 31 (16-55) | < .001 |
| Female sex, no. (%) | 76 (77) | 58 (77) | 18 (75) | .81 |
| Median hemoglobin level at diagnosis, g/L (range) | 140 (90-170) | 140 (90-170) | 140 (100-164) | .69 |
| Median leukocyte count at diagnosis, × 109/L (range) | 9.6 (4-19.2) | 9 (4-18.2) | 10.9 (4-19.2) | .12 |
| Median platelet count at diagnosis, × 109/L (range) | 1323 (1000-3460) | 1338 (1000-3460) | 1280 (1000-2800) | .37 |
| Presence of microvascular symptoms at diagnosis, no. (%) | 29 (29) | 23 (31) | 6 (25) | .59 |
| Median follow-up period, mo (range) | 147 (3-397) | 174 (3-398) | 88 (5-269) | .005 |
| Major thrombosis at follow-up, no. (%) | 21 (21) | 18 (24)* | 3 (13)† | .23 |
| Major hemorrhage at follow-up, no. (%) | 7 (7) | 6 (8)‡ | 1 (4)§ | .52 |
| Prophylactic aspirin therapy, no. (%) | 46 (46) | 33 (44) | 13 (54) | .38 |
| Leukemic transformation rate, % | 8 | 9 | 4 | .42 |
| Fibrotic transformation rate, % | 15 | 16 | 13 | .68 |
. | Entire cohort . | Patients receiving prophylactic cytoreductive therapy . | Patients not receiving prophylactic cytoreductive therapy . | P . |
|---|---|---|---|---|
| No. patients | 99 | 75 | 24 | |
| Median age, y (range) | 43 (16-59) | 45 (16-59) | 31 (16-55) | < .001 |
| Female sex, no. (%) | 76 (77) | 58 (77) | 18 (75) | .81 |
| Median hemoglobin level at diagnosis, g/L (range) | 140 (90-170) | 140 (90-170) | 140 (100-164) | .69 |
| Median leukocyte count at diagnosis, × 109/L (range) | 9.6 (4-19.2) | 9 (4-18.2) | 10.9 (4-19.2) | .12 |
| Median platelet count at diagnosis, × 109/L (range) | 1323 (1000-3460) | 1338 (1000-3460) | 1280 (1000-2800) | .37 |
| Presence of microvascular symptoms at diagnosis, no. (%) | 29 (29) | 23 (31) | 6 (25) | .59 |
| Median follow-up period, mo (range) | 147 (3-397) | 174 (3-398) | 88 (5-269) | .005 |
| Major thrombosis at follow-up, no. (%) | 21 (21) | 18 (24)* | 3 (13)† | .23 |
| Major hemorrhage at follow-up, no. (%) | 7 (7) | 6 (8)‡ | 1 (4)§ | .52 |
| Prophylactic aspirin therapy, no. (%) | 46 (46) | 33 (44) | 13 (54) | .38 |
| Leukemic transformation rate, % | 8 | 9 | 4 | .42 |
| Fibrotic transformation rate, % | 15 | 16 | 13 | .68 |