Table 4. Hazard ratio of all-cause and breast cancer-specific death associated with alcohol drinking by ER positive and negative type.
| Factor | Patients | Person-years | All-cause death | Breast cancer-specific death | ||
|---|---|---|---|---|---|---|
| Deaths | HR (95% CI)a | Deaths | HR (95% CI)a | |||
| ER+ | ||||||
| History of alcohol drinking | ||||||
| Never | 676 | 5430.1 | 99 | 1 (Reference) | 62 | 1 (Reference) |
| Ever (Current/past) | 282 | 2300.2 | 29 | 0.80 (0.50–1.29) | 21 | 0.75 (0.42–1.34) |
| Past | 31 | 244.8 | 2 | 0.53 (0.12–2.26) | 2 | 1.13 (0.25–4.99) |
| Current | 251 | 2055.4 | 27 | 0.83 (0.51–1.36) | 19 | 0.72 (0.39–1.31) |
| Age at start of drinking (years) | ||||||
| ≥ 21 | 121 | 1004.1 | 14 | 0.65 (0.34–1.23) | 10 | 0.64 (0.29–1.44) |
| ≤ 20 | 140 | 1126.7 | 13 | 1.12 (0.58–2.17) | 9 | 0.91 (0.41–2.03) |
| p for trend | 0.82 | 0.55 | ||||
| Frequency of drinking (times) | ||||||
| Occasional or 1–2 per week | 134 | 1099.4 | 12 | 0.81 (0.42–1.56) | 8 | 0.64 (0.29–1.43) |
| 3–7 per week | 135 | 1099.4 | 15 | 0.80 (0.43–1.50) | 11 | 0.86 (0.40–1.84) |
| p for trend | 0.43 | 0.50 | ||||
| Amount of alcohol consumed per day (g) | ||||||
| < 5.0 | 121 | 1000.6 | 10 | 0.71 (0.35–1.43) | 7 | 0.57 (0.25–1.34) |
| ≥ 5.0 | 140 | 1140.3 | 15 | 0.78 (0.42–1.47) | 11 | 0.81 (0.38–1.76) |
| p for trend | 0.34 | 0.40 | ||||
| ER- | ||||||
| History of alcohol drinking | ||||||
| Never | 260 | 1949.0 | 73 | 1 (Reference) | 63 | 1 (Reference) |
| Ever (Current/past) | 103 | 814.7 | 18 | 0.52 (0.27–0.98) | 14 | 0.43 (0.21–0.87) |
| Past | 13 | 81.4 | 4 | 0.50 (0.13–1.86) | 2 | 0.19 (0.03–1.08) |
| Current | 90 | 733.4 | 14 | 0.52 (0.26–1.04) | 12 | 0.49 (0.24–1.03) |
| Age at start of drinking (years) | ||||||
| ≥ 21 | 44 | 354.7 | 8 | 0.53 (0.23–1.20) | 7 | 0.55 (0.23–1.31) |
| ≤ 20 | 49 | 381.7 | 9 | 0.69 (0.29–1.62) | 6 | 0.40 (0.15–1.08) |
| p for trend | 0.20 | 0.04 | ||||
| Frequency of drinking (times) | ||||||
| Occasional or 1–2 per week | 46 | 370.9 | 6 | 0.48 (0.20–1.20) | 4 | 0.38 (0.13–1.11) |
| 3–7 per week | 52 | 414.7 | 9 | 0.48 (0.21–1.10) | 8 | 0.45 (0.19–1.10) |
| p for trend | 0.04 | 0.04 | ||||
| Amount of alcohol consumed per day (g) | ||||||
| < 5.0 | 44 | 352.2 | 6 | 0.52 (0.21–1.31) | 4 | 0.42 (0.14–1.24) |
| ≥ 5.0 | 52 | 425.5 | 9 | 0.45 (0.20–1.03) | 8 | 0.42 (0.18–1.02) |
| p for trend | 0.04 | 0.03 | ||||
| p for interaction between ever-drinking*hormone receptor | 0.41 | 0.19 | ||||
Abbreviations: HR, hazard ratio; CI, confidence interval; ER, estrogen receptor.
aAdjusted by age, year of diagnosis, stage (0-I, II, III, IV, missing), referral status (from screening, other), radiation therapy (no, yes), chemotherapy (no, yes), endocrine therapy (no, yes), family history of breast cancer in parents or siblings (no, yes), smoking (ever, never, missing), BMI(<21.1, 21.1-<23.3, 23.3-<26.0, 26.0-, missing), physical activity (almost no, more than one hour per week, missing), comorbidities (no, yes), occupation (housewife, other, missing), age at menarche (≤12, 13, 14, 15<, missing), parity history (nulliparous, parous, missing), menopausal status (premenopausal, postmenopausal, missing), and intake of folate (continuous) and energy (continuous).