Table 2.

Characteristics of cases and controls among HT never users and exclusive users of ET or EPT

Controls (n = 1,103),*n (%)Cases (n = 715),*n (%)Invasive cases (n = 520),*n (%)OR (95% CI)
Age at diagnosis/reference date (y)
    35-44154 (14.0)120 (16.8)66 (12.7)
    45-54338 (30.6)247 (34.5)162 (31.2)
    55-64348 (31.6)210 (29.4)174 (33.5)
    65-74263 (23.8)138 (19.3)118 (22.7)
Race/ethnicity
    White, non-Hispanic979 (88.8)633 (88.5)463 (89.0)1.0
    Nonwhite, non-Hispanic81 (7.3)52 (7.3)39 (7.5)1.0 (0.7-1.5)
    Hispanic43 (3.9)30 (4.2)18 (3.5)0.9 (0.5-1.6)
Duration of use of hormonal contraceptives
    Never used210 (19.0)209 (29.2)171 (32.9)1.0
    <6 mo77 (7.0)66 (9.2)51 (9.8)0.7 (0.5-1.1)
    6 mo to <5 y404 (36.6)219 (30.6)147 (28.3)0.4 (0.3-0.5)
    5 to <10 y222 (20.1)127 (17.8)94 (18.1)0.4 (0.3-0.6)
    10+ y190 (17.2)94 (13.1)57 (11.0)0.3 (0.2-0.5)
Full-term pregnancies
    0161 (14.6)181 (25.3)119 (22.9)1.0
    1140 (12.7)113 (15.8)87 (16.7)0.8 (0.6-1.2)
    2364 (33.0)198 (27.7)136 (26.2)0.5 (0.3-0.6)
    3245 (22.2)132 (18.5)102 (19.6)0.5 (0.4-0.7)
    4+193 (17.5)91 (12.7)76 (14.6)0.5 (0.3-0.7)
Tubal ligation
    No863 (78.2)589 (82.4)435 (83.7)1.0
    Yes240 (21.8)126 (17.6)85 (16.3)0.7 (0.5-0.9)
Hysterectomy
    No891 (80.8)566 (79.2)409 (78.7)1.0
    Yes212 (19.2)149 (20.8)111 (21.3)1.1 (0.9-1.5)
Family history of breast and ovarian cancer
    None671 (61.5)416 (58.8)295 (57.5)1.0
    Breast cancer only341 (31.3)210 (29.7)151 (29.4)1.0 (0.8-1.3)
    Ovarian cancer only47 (4.3)52 (7.4)42 (8.2)2.1 (1.3-3.3)
    Breast and ovarian cancer32 (2.9)29 (4.1)25 (4.9)1.8 (1.0-3.1)
Prior breast cancer
    No1,045 (94.7)667 (93.3)476 (91.5)1.0
    Yes58 (5.3)48 (6.7)44 (8.5)1.7 (1.1-2.5)
Body mass index at age 30
    <18.575 (6.9)37 (5.2)30 (5.8)0.9 (0.6-1.3)
    18.5-24.9826 (75.7)520 (73.4)386 (74.7)1.0
    25-29.9127 (11.6)91 (12.9)58 (11.2)1.0 (0.7-1.4)
    30+63 (5.8)60 (8.5)43 (8.3)1.5 (1.0-2.3)
Age at last full-term pregnancy
    No full-term pregnancies161 (14.6)181 (25.3)119 (22.9)1.0
    <25 y172 (15.6)147 (20.6)114 (21.9)0.8 (0.6-1.2)
    25-29 y308 (27.9)173 (24.2)138 (26.5)0.6 (0.4-0.8)
    30-34 y295 (26.8)145 (20.3)99 (19.0)0.4 (0.3-0.6)
    35+ y166 (15.1)69 (9.7)50 (9.6)0.4 (0.3-0.6)
Menopausal status (see text for definition)
    Premenopausal355 (32.2)267 (37.3)167 (32.1)1.0
    Natural menopause420 (38.1)226 (31.6)179 (34.4)1.0 (0.6-1.5)
    Induced menopause12 (1.1)10 (1.4)10 (1.9)1.8 (0.8-4.5)
    Assumed natural menopause239 (21.7)162 (22.7)137 (26.3)1.3 (0.8-2.1)
    Unclear77 (7.0)50 (7.0)27 (5.2)0.7 (0.4-1.1)
Vasomotor symptoms
    No367 (33.3)269 (37.6)180 (34.6)1.0
    Yes736 (66.7)446 (62.4)340 (65.4)0.9 (0.7-1.1)
  • * n of individual variables may not sum to total due to missing values.

  • Odds ratios for invasive epithelial ovarian cancer, adjusted for age, reference year, and county of residence.