Table 1. Patient baseline characteristics and demographics.
| Characteristic | Lenalidomide-treated (n=295) | Untreated (n=125) |
|---|---|---|
| Year of diagnosis, range | 1977–2007 | 1983–2009 |
| Before 1990, n (%) | 5 (1.7) | 10 (8.0) |
| 1990–1999, n (%) | 55 (18.6) | 39 (31.2) |
| 2000–2009, n (%) | 235 (79.7) | 76 (60.8) |
| Median time from diagnosis to study entry (range), years | 2.7 (0.1–29.2) | 0 |
| Median age (range), years | 65 (32–94) | 66 (30–91) |
| Male, n (%) | 87 (29.5) | 40 (32.0) |
| French-American-British classification, n (%) | ||
| Refractory anemia | 216 (73.2) | 96 (76.8) |
| Refractory anemia with ringed sideroblasts | 21 (7.1) | 10 (8.0) |
| Refractory anemia with excess blasts | 54 (18.3) | 19 (15.2) |
| Other or missing | 4 (1.4) | 0 |
| Bone marrow blast count 5–10%, n (%) | 31 (10.5)a | 20 (16.0) |
| Cytogenetics, n (%) | ||
| Isolated del(5q) | 224 (75.9) | 104 (83.2) |
| del(5q) plus 1 additional abnormality | 53 (18.0) | 16 (12.8) |
| del(5q) plus >1 additional abnormality | 16 (5.4) | 5 (4.0) |
| Missing | 2 (0.7) | 0 |
| Patients with WHO-defined isolated del(5q), n (%)b | 160 (54.2) | 85 (68.0)c |
| IPSS risk, n (%)d | ||
| Low | 104 (35.3) | 50 (40.0) |
| Intermediate-1 | 139 (47.1) | 66 (52.8) |
| Missing data | 52 (17.6) | 9 (7.2) |
| Median RBC transfusion burden (range), units/8 weeks | 6 (1–25) | 2 (1–10)e |
| Median hemoglobin level (range), g/dl | 8.3 (4.3–12.7) | 8.1 (3.0–12.3) |
| Median platelet count (range), × 109/l | 245 (51–1 275) | 261 (55–1 540) |
| Median neutrophil count (range), × 106/l | 2170 (590–20 980) | 2390 (510–28 782) |
Abbreviations: IPSS, International Prognostic Scoring System; RBC, red blood cell; WHO, World Health Organization.
a
Data not available for 50 patients.
b
Defined as patients who had isolated del(5q) and <5% bone marrow blasts.
c
P<0.05 vs lenalidomide-treated patients.
d
Information on whether patients had IPSS Low- or Intermediate-1-risk disease was available for 243 lenalidomide-treated and 116 untreated patients. The remaining patients had either Low- or Intermediate-1-risk disease, but exact IPSS scores were not clearly definable due to missing data.
e
Data not available for 20 patients (French registry); P<0.001 vs lenalidomide-treated patients.