Table 4. Clinical characteristics of patients with WHO-defined ET compared with WHO-defined prefibrotic primary myelofibrosis (prePMF) at presentation as derived from the BCSH-confirmed ET cohort.
| WHO-defined ET3 | WHO-defined prePMF3 | P-value | |
|---|---|---|---|
| General characteristics | |||
| n | 141 | 77 | |
| Age at diagnosis (years) | 58.9 (18.8–88.8) | 64.6 (23.2–88.1) | 0.083 |
| Sex; male/female | 58/83 | 27/50 | 0.486 |
| Clinical characteristicsa | |||
| Platelets (× 109/l) | 725 (452–1836) | 840 (457–2530) | 0.012 |
| Hemoglobin (g/dl) | 14.5 (11.5–17.3) | 13.9 (8.6–16.6) | 0.007 |
| Hematocrit (%) | 43.0 (33.2–52.0) | 41.6 (27.5–48.9) | 0.036 |
| WBC (× 109/l) | 8.8 (2.2–21.1) | 10.3 (4.0–31.3) | 0.004 |
| LDH (U/l) | 209 (110–763) | 270 (136–598) | <0.001 |
| Palpable splenomegaly (141/77)b | 9.9% (14) | 23.4% (18) | 0.009 |
| Fibrosis grading ⩾1 | 0.0% (0) | 20.8% (16) | <0.001 |
| Molecular characteristics | |||
| Pathogenetic mutation present (141/77)b | 100% (141) | 100% (77) | — |
| JAK2 V617F (141/77)b | 70.9% (100) | 61.0% (47) | 0.011 |
| CALR (99/65)b | 27.3% (27) | 41.5% (27) | 0.064 |
| MPL (33/37)b | 12.1% (4) | 8.1% (3) | 0.699 |
| Symptoms at diagnosis | |||
| Constitutional symptoms (111/71)b | 15.8% (16) | 20.3% (10) | 1.000 |
| Weight loss | 3.6% (4) | 7.0% (5) | 0.315 |
| Night sweats | 8.1% (9) | 4.2% (3) | 0.372 |
| Fatigue | 5.4% (6) | 5.6% (4) | 1.000 |
| Pruritus (111/71)b | 1.8% (2) | 1.4% (1) | 1.000 |
| Cytoreductive therapy (108/63)b | |||
| Hydroxyurea | 45.4% (49) | 38.1% (24) | 0.423 |
| Interferon-alpha | 31.5% (34) | 34.9% (22) | 0.736 |
| Anagrelide | 33.3% (36) | 28.6% (18) | 0.610 |
| JAK1/2-inhibitor | 4.6% (5) | 6.3% (4) | 0.727 |
| Busulfan | 1.9% (2) | 3.2% (2) | 0.626 |
| Othersc | 0.9% (1) | 6.3% (4) | 0.062 |
| Antithrombotic therapy with low-dose aspirin (106/63)b | 89.6% (95) | 88.9% (56) | 1.000 |
Abbreviations: BCSH, British Committee of Standards in Haematology; CALR, calreticulin exon 9 mutations; ET, essential thrombocythemia; JAK2, Janus kinase 2; LDH, serum lactate dehydrogenase; MPL, myeloproliferative leukemia oncogene; WBC, white blood cell count.
a
Median, range.
b
Number evaluable in each cohort.
c
Pipobroman, P32 and other cytoreductive agents.