Table 1.
Patient and control characteristics.
| Cancer diagnosis | Number of patients | Mean age and range* | Treatment duration – mean and range** |
| Leukemia group – total | 77 | 6.44 (0.5–16.0) | 1.54 (0.7–2.2) |
| - Acute lymphoblastic leukemia | 62 | ||
| - Acute myeloid leukemia | 14 | ||
| - Myelodysplastic syndrome | 1 | ||
| Lymphoma group – total | 42 | 12.07(2.0–17.8) | 0.81 (0.6–1.0) |
| - Hodgkin's disease | 27 | ||
| - Non-Hodgkin's lymphoma | 15 | ||
| Histiocytosis group – total | 9 | 3.34 (0.3–12.7) | 0.72(0.5–1.0) |
| - Class I. | 7 | ||
| - Class II. | 2 | ||
| Solid tumor group – total | 58 | 7.41 (0.7–17.5) | 0.96 (0.5–2.0) |
| - Brain tumors | 21 | ||
| - Neuroblastoma and PPNET*** | 10 | ||
| - Wilms tumor | 7 | ||
| - Soft tissue sarcoma | 7 | ||
| - Retinoblastoma | 5 | ||
| - Osteosarcoma | 5 | ||
| - Ewing sarcoma | 3 | ||
| Total | 186 | 7.86(0.3–17.5) | 1.15 (0.5–2.2) |
| Controls – pediatric | 218 | 8.21 (0.3–17.3) | - |
| - adult | 165 | 47.53(19–78) | - |
* Mean age in years at the time of cancer diagnosis; (range). ** Mean interval in years between sample taken at the time of cancer diagnosis and the time 2 months after the completion of anti-cancer treatment; (range). *** 8 patients with neuroblastoma (2 patients with stage II., 2 patients with stage III. and 4 patients with stage IV.) and 2 patients with PPNET = peripheral primitive neuroectodermal tumor.