Table 1.
Descriptive characteristics of hairy cell leukemia cases and controls
| Controls, N (%) | Cases, N (%) | |
|---|---|---|
| Total | 8834 (98.3) | 154 (1.7) |
| Study | ||
| Europe | ||
| Engela | 722 (8.2) | 36 (23.4) |
| EpiLymph | 2460 (27.8) | 15 (9.7) |
| Italy multicenter | 1771 (20.0) | 30 (19.5) |
| SCALE | 3187 (36.1) | 63 (40.9) |
| Australia | ||
| New South Wales | 694 (7.9) | 10 (6.5) |
| Region | ||
| North America | 0 (0.0) | 0 (0.0) |
| Northern Europe | 5403 (61.2) | 112 (72.7) |
| Southern Europe | 2737 (31.0) | 32 (20.8) |
| Australia | 694 (7.9) | 10 (6.5) |
| Design | ||
| Population-based | 6698 (75.8) | 109 (70.8) |
| Hospital-based | 2136 (24.2) | 45 (29.2) |
| Age | ||
| <30 | 640 (7.2) | 1 (0.6) |
| 30–39 | 750 (8.5) | 14 (9.1) |
| 40–49 | 1241 (14.0) | 38 (24.7) |
| 50–59 | 2072 (23.5) | 48 (31.2) |
| 60–69 | 2614 (29.6) | 43 (27.9) |
| 70–79 | 1454 (16.5) | 10 (6.5) |
| ≥80 | 63 (0.7) | 0 (0.0) |
| Sex | ||
| Male | 4840 (54.8) | 121 (78.6) |
| Female | 3994 (45.2) | 33 (21.4) |
| Race | ||
| White, non-Hispanic | 8501 (96.2) | 148 (96.1) |
| Black | 2 (0.0) | 0 (0.0) |
| Asian | 14 (0.2) | 0 (0.0) |
| Hispanic | 0 (0.0) | 0 (0.0) |
| Other or unknown or missing | 317 (3.6) | 6 (3.9) |
| Socioeconomic status | ||
| Low | 3446 (39.0) | 47 (30.5) |
| Medium | 3015 (34.1) | 39 (25.3) |
| High | 2320 (26.3) | 67 (43.5) |
| Other or missing | 53 (0.6) | 1 (0.6) |
| Non-Hodgkin lymphoma classification | ||
| World Health Organization | 7063 (80.0) | 124 (80.5) |
| Working Formulation | 1771 (20.0) | 30 (19.5) |