Table 1

Epidemiological risk factors in cases and controls

Cases Number (%)Controls Number (%)P
Age (mean ± SE, yr)54.0 ± 1.1452.8 ± 1.030.45
Menopausal status
 Premenopausal52 (51)45 (45)0.40
 Postmenopausal50 (49)55 (55)
Family historya
 Yes5 (5)8 (8)0.37
 No97 (95)92 (92)
Age at menarche (yr)
 ≥1451 (50)40 (40)0.22
 1324 (24)34 (34)
 ≤1227 (26)26 (26)
Age at first live birth or no delivery (yr)
 ≤2316 (16)19 (19)0.11
 24–2514 (14)27 (27)
 26–2934 (33)25 (25)
 ≥3010 (10)10 (10)
 Nulliparous28 (27)19 (19)
BMI (kg/m2)
 <21.038 (37)34 (34)0.69
 ≥21.0, <23.028 (27)33 (33)
 ≥23.036 (35)33 (33)
Age at menopause (yr)
 ≤4811 (22)23 (42)0.09
 49–5120 (40)16 (29)
 ≥5219 (38)16 (29)
  • a Family history of breast cancer in first-degree relatives.