Table 3 Multivariable Cox proportional hazard regression analyses for subsequent breast cancer by chest radiotherapy status among female 5-year childhood cancer survivors (primary cancer diagnosis year 1946–2012)
From: Subsequent female breast cancer risk associated with anthracycline chemotherapy for childhood cancer
Models without interaction | ||||
|---|---|---|---|---|
Characteristic | With chest radiotherapya | Without chest radiotherapya | ||
HR | 95% CI | HR | 95% CI | |
Continuous variable: cumulative doxorubicin dose (per 100 mg m−²) | 1.11 | 1.02–1.21 | 1.26 | 1.17–1.36 |
Continuous variable: cumulative daunorubicin dose (per 100 mg m−²) | 0.95 | 0.74–1.21 | 1.12 | 0.93–1.36 |
Epirubicin | ||||
No | 1.0 | Ref. | 1.0 | Ref. |
Yes | 2.28 | 1.00–5.21 | 2.13 | 0.49–9.17 |
Models with a multiplicative interaction | ||||
– | Interaction: cumulative doxorubicin dose × chest radiotherapy status (yes/no) | Interaction: cumulative daunorubicin dose × chest radiotherapy status (yes/no) | ||
HR | 95% CI | HR | 95% CI | |
Continuous variable: Cumulative doxorubicin dose (per 100 mg m−²) | 1.28 | 1.21–1.37 | 1.21 | 1.15–1.28 |
Continuous variable: cumulative daunorubicin dose (per 100 mg m−²) | 1.04 | 0.89–1.23 | 1.15 | 0.96–1.37 |
Epirubicin | ||||
No | 1.0 | Ref. | 1.0 | Ref. |
Yes | 2.54 | 1.22–5.30 | 2.47 | 1.17–5.23 |
Interaction: cumulative doxorubicin dose (per 100 mg m−2) × chest radiotherapy status (yes/no) | 0.86 | 0.78–0.96 | – | – |
Interaction: cumulative daunorubicin dose (per 100 mg m−2) × chest radiotherapy status (yes/no) | – | – | 0.77 | 0.57–1.05 |
