Table 1. Characteristics of the children included in the study stratified by childhood cancer status (background vs childhood cancer survivors).
| Variable | Background N=792 012 | Survivors N=1320 | Proportion of cancer survivors with grades | Proportion of cases at risk in ninth grade |
|---|---|---|---|---|
| Age mean (s.d.) | 15.24 (0.44) | 15.32 (0.48) | ||
| Gender (%) | ||||
| Male | 398 168 (50.3) | 689 (52.2) | ||
| Female | 393 844 (49.7) | 631 (47.8) | ||
| Birth year (%) | ||||
| Before 1990 | 284 775 (36.0) | 503 (38.1) | ||
| (1990,1995) | 323 875 (40.9) | 498 (37.7) | ||
| After 1995 | 183 362 (23.2) | 319 (24.2) | ||
| Age at diagnosis (%) | ||||
| Between 0 and 2 | 199 (15.1) | |||
| Between 2 and 5 | 326 (24.7) | |||
| Between 5 and 10 | 332 (25.2) | |||
| Between 10 and 15 | 463 (35.1) | |||
| Cancer site | ||||
| Leukaemia | 417 (31.6) | 96.3 | 77.2 | |
| Lymphomas | 158 (12.0) | 94.6 | 87.4 | |
| CNS tumour | 269 (20.4) | 72.9 | 68.7 | |
| Neuroblastoma | 54 (4.1) | 100 | 50.0 | |
| Retinoblastoma | 55 (4.2) | 100 | 98.2 | |
| Renal tumour | 75 (5.7) | 93.4 | 87.0 | |
| Hepatic tumour | 14 (1.1) | 93.3 | 68.2 | |
| Bone tumour | 62 (4.7) | 100 | 53.3 | |
| Soft tissue sarcoma | 70 (5.3) | 94.5 | 63.8 | |
| Germ-cell tumour | 38 (2.9) | 79.1 | 80.0 | |
| Malignant epithelial tumour | 93 (7.0) | 97.9 | 92.2 | |
| Other malignant neoplasm | 15 (1.1) | 93.7 | 88.9 |
Abbreviation: CNS=central nervous system.