Table 3. Five-, 10-, and 15-year cumulative incidence according to risk factors and hazard ratio in multivariate analysis.
| Characteristic | 5 yr (%) | 10 yr (%) | 15 yr (%) | p-value* | HR (95% CI) | p-value |
|---|---|---|---|---|---|---|
| Age at diagnosis (yr) | < 0.001† | |||||
| < 50 | 0.4 | 0.8 | 1.7 | < 0.001 | 1 | < 0.001 |
| ≥ 50 | 1.5 | 4.3 | 5.7 | 1.073 (1.048–4.099) | ||
| Laterality | 0.443 | 0.428 | ||||
| Right | 0.6 | 1.9 | 2.8 | 1 | ||
| Left | 1.0 | 2.3 | 3.5 | 1.212 (0.753–1.950) | ||
| Year of radiotherapy | 0.491 | |||||
| 1996–2000 | 0.9 | 2.3 | 2.3 | |||
| 2001–2005 | 0.6 | 1.6 | 1.6 | |||
| 2006–2010 | 0.9 | 2.2 | 3.5 | |||
| BMI (kg/m2) | < 0.001† | 1.005 (0.962–1.051) | 0.816 | |||
| < 25 | 0.6 | 1.6 | 2.2 | < 0.001 | 1 | 0.151 |
| ≥ 25 | 1.5 | 3.5 | 5.8 | 1.764 (0.607–5.128) | ||
| Smoking | 0.042 | 0.002 | ||||
| No | 0.8 | 2.2 | 3.4 | 1 | ||
| Yes | 3.3 | 6.2 | 6.2 | 5.991 (2.109–17.022) | ||
| Hyperlipidemia | < 0.001 | < 0.001 | ||||
| No | 0.4 | 1.2 | 1.7 | 1 | ||
| Yes | 5.2 | 10.6 | 15.3 | 5.567 (3.235–9.580) | ||
| Hypertension | < 0.001 | 0.228 | ||||
| No | 0.7 | 1.7 | 2.4 | 1 | ||
| Yes | 3.0 | 7.5 | 12.1 | 1.460 (0.789–2.703) | ||
| Diabetes | < 0.001 | 0.068 | ||||
| No | 0.7 | 1.6 | 2.2 | 1 | ||
| Yes | 3.7 | 8.8 | 16.0 | 1.786 (0.957–3.331) | ||
| Anthracycline | 0.079 | |||||
| No | 0.7 | 1.3 | 2.5 | |||
| Yes | 0.9 | 3.0 | 3.7 | |||
| Trastuzumab | 0.010 | 0.039 | ||||
| No | 0.8 | 1.8 | 2.9 | 1 | ||
| Yes | 1.0 | 4.7 | 6.7 | 2.214 (1.040–4.711) |
HR=hazard ratio; CI=confidence interval; BMI=body mass index.
*p-value obtained from univariate Cox regression analysis; †p-value obtained from univariate Cox regression analysis calculated as continuous variables.