Table 3 Risk factors associated with increased or decreased risk of breast cancer.
From: Breast cancer risk factors in Turkish women – a University Hospital based nested case control study
Factors associated with increased breast cancer risk: | women in the control group (n = 2167) (%) | patients with breast cancer (n = 1492) (%) | OR (95%CI) | P value |
|---|---|---|---|---|
Age (≥ 50) years | 34.0 | 58.8 | 2.78 (2.42–3.18) | < 0.001 |
Induced abortion | 42.9 | 49.7 | 1.31 (1.13–1.53) | < 0.001 |
Body mass index ≥ 25 | 55.2 | 64.2 | 1.46 (1.27–1.68) | < 0.001 |
Family history of breast cancer (first degree relative) | 5.0 | 7.2 | 1.46 (1.11–1.92) | 0.008 |
Age at first birth (≥ 35 years) | 0.9 | 2.6 | 3.06 (1.62–5.77) | < 0.001 |
Factors associated with decreased breast cancer risk: | ||||
Education (≥ 13 years) | 48.8 | 40.3 | 0.71 (0.62–0.81) | < 0.001 |
Spontaneous abortion | 28.9 | 22.5 | 0.71 (0.60–0.85) | < 0.001 |
Smoking | 29.9 | 23.5 | 0.72 (0.61–0.85) | < 0.001 |
Breast feeding | 98.4 | 91.5 | 0.17 (0.11–0.27) | < 0.001 |
Oral contraceptive use | 27.8 | 18.4 | 0.59 (0.50–0.69) | < 0.001 |
Nullipara | 20.8 | 16.2 | 0.95 (0.92–0.98) | < 0.001 |
Hormone replacement therapy | 10.8 | 4.1 | 0.35 (0.26–0.47) | < 0.001 |