Patient characteristics at enrollment
| Variable . | Low-risk PV, n = 503 . | High-risk PV, n = 1768 . | All patients, N = 2271 . |
|---|---|---|---|
| Age, median (range), y | 53 (22-59) | 71 (28-95) | 67 (22-95) |
| <60 y, n (%) | 503 (100.0) | 118 (6.7) | 621 (27.3) |
| ≥60 y, n (%) | 0 | 1650 (93.3) | 1650 (72.7) |
| Male, n (%) | 299 (59.4) | 930 (52.6) | 1229 (54.1) |
| Disease duration, median (range), y | 3.2 (0-39.2) | 4.3 (0-56.3) | 4.1 (0-56.3) |
| History of TE, n (%) | 0 | 456 (25.8) | 456 (20.1) |
| Aspirin treatment, n (%) | 349 (69.4) | 1175 (66.5) | 1524 (67.1) |
| Anticoagulant treatment, n (%) | 10 (2.0) | 252 (14.3) | 262 (11.5) |
| PV treatment at or before enrollment, n (%) | |||
| Phlebotomy only | 273 (54.3) | 478 (27.0) | 751 (33.1) |
| HU only | 91 (18.1) | 563 (31.8) | 654 (28.8) |
| Phlebotomy + HU | 79 (15.7) | 470 (26.6) | 549 (24.2) |
| Other∗ | 35 (7.0) | 150 (8.5) | 185 (8.1) |
| Watchful waiting only | 25 (5.0) | 107 (6.1) | 132 (5.8) |
| Variable . | Low-risk PV, n = 503 . | High-risk PV, n = 1768 . | All patients, N = 2271 . |
|---|---|---|---|
| Age, median (range), y | 53 (22-59) | 71 (28-95) | 67 (22-95) |
| <60 y, n (%) | 503 (100.0) | 118 (6.7) | 621 (27.3) |
| ≥60 y, n (%) | 0 | 1650 (93.3) | 1650 (72.7) |
| Male, n (%) | 299 (59.4) | 930 (52.6) | 1229 (54.1) |
| Disease duration, median (range), y | 3.2 (0-39.2) | 4.3 (0-56.3) | 4.1 (0-56.3) |
| History of TE, n (%) | 0 | 456 (25.8) | 456 (20.1) |
| Aspirin treatment, n (%) | 349 (69.4) | 1175 (66.5) | 1524 (67.1) |
| Anticoagulant treatment, n (%) | 10 (2.0) | 252 (14.3) | 262 (11.5) |
| PV treatment at or before enrollment, n (%) | |||
| Phlebotomy only | 273 (54.3) | 478 (27.0) | 751 (33.1) |
| HU only | 91 (18.1) | 563 (31.8) | 654 (28.8) |
| Phlebotomy + HU | 79 (15.7) | 470 (26.6) | 549 (24.2) |
| Other∗ | 35 (7.0) | 150 (8.5) | 185 (8.1) |
| Watchful waiting only | 25 (5.0) | 107 (6.1) | 132 (5.8) |
Risk status was assessed based on National Comprehensive Cancer Network guidelines.12
Other treatments: ruxolitinib (4.4%), anagrelide (2.2%), interferon (1.5%), busulfan (0.2%), and chlorambucil (0%).