Table 2:
Risk of secondary leukemia in relation to radiotherapy or/and chemotherapy.
| Treatment characteristics | Cases / Controls | Univariate analyses | Multivariable analysis |
|---|---|---|---|
| Odds ratio$ (95% CI) | Odds ratio$ (95% CI) | ||
| Radiotherapy | |||
| No | 50/224 | 1.0 (Reference) | 1.0 (Reference) |
| Yes | 97/298 | 1.6 (1.0-2.4) | 1.5 (0.99-2.3) |
| P-value for heterogeneity | 0.03 | 0.06 | |
| Chemotherapy | |||
| No | 15/151 | 1.0 (Reference) | 1.0 (Reference) |
| Yes | 132/371 | 6.2 (2.9-13.3) | 5.5 (2.6-12.0) |
| P-value for heterogeneity | <0.0001 | <0.0001 | |
| Treatment combination | |||
| Nor radiotherapy nor chemotherapy | 2/65 | 1.0 (Reference) | |
| Radiotherapy alone | 13/86 | 6.4 (1.3-30.3) | |
| Chemotherapy alone | 48/159 | 19.0 (3.8-94.7) | |
| Radiotherapy and chemotherapy | 84/212 | 24.6 (5.0-120.8) | |
| P-value for heterogeneity | 0.0001 | ||
Abbreviations: 95% CI = 95% confidence interval.
$
Conditional logistic regression matched on gender, age at childhood cancer diagnosis and follow-up, and the multivariable analysis, adjusted for radiotherapy, chemotherapy and year of diagnosis.