Table 3.

Exogenous factors and risk for breast cancer defined by joint ER and PR status

Control group
ERPR
ER+PR
ERPR+
ER+PR+
Unknown ERPR
P, Wald (df)*
nnOR (95% CI)nOR (95% CI)nOR (95% CI)nOR (95% CI)nOR (95% CI)
Menopausal hormone therapy
    Estrogen alone
        No use2,3842251.0 (Ref)2001.0 (Ref)411.0 (Ref)7711.0 (Ref)5421.0 (Ref)
        All use
            Ever222411.9 (1.3-2.7)301.6 (1.1-2.5)133.2 (1.7-6.2)1351.9 (1.5-2.5)871.7 (1.3-2.3)0.88 (1)
            Current130231.9 (1.2-3.0)181.8 (1.0-3.0)83.5 (1.6-7.6)691.7 (1.2-2.3)501.8 (1.2-2.5)0.59 (1)
        Exclusive use§
            Ever141262.0 (1.3-3.1)181.6 (1.0-2.7)83.3 (1.5-7.2)791.8 (1.3-2.4)521.7 (1.2-2.4)0.70 (1)
        Duration (y)
            <585131.6 (0.9-3.0)142.0 (1.1-3.7)10.6 (0.1-4.5)361.3 (0.9-2.0)311.7 (1.1-2.5)0.86 (2)
            ≥545102.4 (1.2-4.8)41.2 (0.4-3.3)710.2 (4.2-24.6)332.4 (1.5-3.8)192.0 (1.1-3.4)
        Recency
            Current5861.0 (0.4-2.4)40.9 (0.3-2.6)43.5 (1.2-10.3)311.7 (1.1-2.6)241.9 (1.2-3.1)0.25 (2)
            Past72172.7 (1.5-4.6)142.4 (1.3-4.4)43.5 (1.2-10.1)381.7 (1.1-2.5)261.7 (1.0-2.7)
    Estrogen-progestin
        No use2,3842251.0 (Ref)2001.0 (Ref)411.0 (Ref)7711.0 (Ref)5421.0 (Ref)
        All use
            Ever409661.4 (1.0-1.9)551.7 (1.2-2.4)222.4 (1.4-4.3)2612.0 (1.6-2.4)1631.7 (1.4-2.2)0.068 (1)
            Current289411.2 (0.8-1.8)411.8 (1.3-2.7)162.5 (1.3-4.7)1771.9 (1.5-2.4)1211.9 (1.5-2.4)0.036 (1)
        Exclusive use§
            Ever306441.3 (0.9-1.8)421.8 (1.2-2.6)162.4 (1.3-4.4)1821.8 (1.5-2.3)1221.8 (1.4-2.3)0.067 (1)
        Duration (y)
            <5201291.2 (0.8-1.8)261.6 (1.0-2.6)122.5 (1.2-5.1)981.4 (1.1-1.9)591.3 (0.9-1.7)0.051 (2)
            ≥588121.3 (0.7-2.5)152.3 (1.3-4.1)42.6 (0.9-7.5)783.0 (2.1-4.1)623.4 (2.4-4.9)
        Recency
            Current191261.1 (0.7-1.8)271.8 (1.2-2.9)143.2 (1.6-6.4)§1312.2 (1.7-2.8)982.4 (1.8-3.2)0.037 (2)
            Past98151.4 (0.8-2.5)141.9 (1.0-3.4)21.1 (0.2-4.5)451.4 (1.0-2.0)231.7 (1.0-2.7)
Oral contraceptives
    No use2,0932041.0 (Ref)1981.0 (Ref)451.0 (Ref)7631.0 (Ref)5501.0 (Ref)0.29 (2)
    <5 y477520.9 (0.6-1.2)340.8 (0.5-1.1)130.8 (0.4-1.6)1961.0 (0.8-1.3)1381.1 (0.8-1.3)
    ≥5 y341531.3 (0.9-1.8)351.2 (0.8-1.8)100.9 (0.4-1.8)1421.1 (0.9-1.4)760.8 (0.6-1.1)
Recent alcohol use (g/d)
    No alcohol1,1391291.0 (Ref)1141.0 (Ref)381.0 (Ref)4591.0 (Ref)3211.0 (Ref)0.52 (3)
    <59251281.2 (0.9-1.5)1101.3 (0.9-1.7)220.6 (0.3-1.0)4011.0 (0.8-1.2)2771.1 (0.9-1.3)
    ≥5 to 10216321.2 (0.8-1.9)221.1 (0.7-1.8)30.3 (0.1-1.1)1301.2 (0.9-1.6)671.1 (0.8-1.5)
    >10100191.6 (0.9-2.7)141.4 (0.8-2.6)10.2 (0.0-1.8)501.0 (0.6-1.6)421.5 (1.0-2.3)
Recent smoking
    No2,2752631.0 (Ref)2131.0 (Ref)551.0 (Ref)9021.0 (Ref)5971.0 (Ref)0.23 (1)
    Yes712690.8 (0.6-1.0)731.2 (0.9-1.6)160.8 (0.4-1.4)2611.0 (0.8-1.1)1891.1 (0.9-1.3)
  • NOTE: All use, use of other types of hormone therapy allowed; exclusive use, only use of one type of hormone therapy. Recency: current, last use ≤6 months before reference date; past, last use >6 months before reference date. Recent, 1 year before data collection.

  • * P value for association from case-case analysis for ER+PR+ compared with ERPR cancer, in a model adjusted for age, BMI, age at first birth, and tumor size.

  • All ORs adjusted for age, BMI, and age at first birth.

  • No use: no use of any kind of menopausal hormone therapy (apart from oral estriol or local estrogen).

  • § Users of more than one kind of therapy excluded.