Table 3.
Number of older children in household (“siblings”) at time of index birth for acute lymphoblastic leukaemia (ALL), ALL subgroups, and non-ALL malignancies
|
ALL
|
cALL
|
TEL-AML1
|
Hyperdiploid ALL
|
Non-ALL malignancies
|
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| No of siblings | Controls No (%) | No (%) | Odds ratio*(95% CI) | No (%) | Odds ratio*(95% CI) | No (%) | Odds ratio*(95% CI) | No (%) | Odds ratio*(95% CI) | No (%) | Odds ratio*(95% CI) |
|
Cases aged over 2 years
|
|
|
|
|
|
|
|
|
|
|
|
| Total No†
|
6197
|
1270
|
789
|
138
|
416
|
1830
|
|||||
| None | 2690 (43.4) | 565 (44.5) | 1.00 | 365 (46.3) | 1.00 | 62 (44.9) | 1.00 | 189 (45.4) | 1.00 | 799 (43.7) | 1.00 |
| 1 | 2216 (35.8) | 443 (34.9) | 0.96 (0.84 to 1.11) | 266 (33.7) | 0.88 (0.74 to 1.05) | 49 (35.5) | 0.89 (0.60 to 1.32) | 149 (35.8) | 0.97 (0.77 to 1.22) | 667 (36.5) | 1.03 (0.91 to 1.16) |
| 2 | 899 (14.5) | 182 (14.3) | 0.99 (0.82 to 1.21) | 115 (14.6) | 0.94 (0.74 to 1.20) | 20 (14.5) | 0.86 (0.50 to 1.48) | 57 (13.7) | 0.94 (0.68 to 1.30) | 281 (15.4) | 1.11 (0.94 to 1.31) |
| ≥3 | 392 (6.3) | 80 (6.3) | 0.99 (0.74 to 1.30) | 43 (5.4) | 0.78 (0.54 to 1.12) | 7 (5.1) | 0.70 (0.30 to 1.62) | 21 (5.0) | 0.75 (0.46 to 1.25) | 83 (4.5) | 0.76 (0.59 to 1.00) |
| P for trend‡ | 0.9 | 0.2 | 0.4 | 0.4 | 0.7 | ||||||
|
Cases aged 2-5 years
|
|
|
|
|
|
|
|
|
|
|
|
| Total†
|
2463
|
673
|
473
|
82
|
248
|
548
|
|||||
| None | 1071 (43.5) | 308 (45.8) | 1.00 | 221 (46.7) | 1.00 | 40 (48.8) | 1.00 | 114 (46.0) | 1.00 | 256 (46.7) | 1.00 |
| 1 | 873 (35.4) | 233 (34.6) | 0.95 (0.78 to 1.16) | 164 (34.7) | 0.93 (0.74 to 1.17) | 29 (35.4) | 0.81 (0.49 to 1.36) | 89 (35.9) | 0.98 (0.72 to 1.33) | 186 (33.9) | 0.95 (0.77 to 1.19) |
| 2 | 366 (14.9) | 96 (14.3) | 0.95 (0.72 to 1.25) | 65 (13.7) | 0.89 (0.65 to 1.22) | 8 (9.8) | 0.52 (0.23 to 1.16) | 35 (14.1) | 0.97 (0.64 to 1.48) | 81 (14.8) | 1.05 (0.78 to 1.40) |
| ≥3 | 153 (6.2) | 36 (5.3) | 0.85 (0.56 to 1.29) | 23 (4.9) | 0.72 (0.44 to 1.19) | 5 (6.1) | 0.81 (0.29 to 2.25) | 10 (4.0) | 0.61 (0.29 to 1.27) | 25 (4.6) | 0.80 (0.50 to 1.28) |
| P for trend‡ | 0.5 | 0.2 | 0.2 | 0.4 | 0.7 | ||||||
cALL=B cell precursor common ALL; TEL-AML1=ALL with fusion of the TEL and AML1 genes.
*
Odds ratio for cases compared with all controls, adjusted for age at diagnosis/pseudo diagnosis, sex, region, maternal age, mother working at time of birth, and deprivation.
†
Excluding missing values.
‡
Trend test across categories none through to ≥3.