Table 1.

Distribution of selected characteristics of breast cancer patients according to OC use status in the Women's CARE Study and the CTS

Women's CARE study (N = 4,565) OC useCTS (age 35–64; N = 2,222) OC useCTS (all; N = 3,929) OC use
Never (N = 1,041)Ever (N = 3,524)Never (N = 395)Ever (N = 1,827)Never (N = 1,490)Ever (N = 2,439)
Age at diagnosis, y
 Black (CARE)/other (CTS)
Family history of breast cancer (first degree)
Body mass index (BMI)a, kg/m2
Menopausal status
Estrogen status
Study site
 Los Angeles26.127.5
 Not a high school graduate16.36.5
 High school graduate34.927.5
 Some college or technical school26.434.2
 College graduate22.331.8
Socioeconomic status
 Lowest quartile3.
 Second quartile13.914.716.314.4
 Third quartile28.630.830.530.5
 Highest quartile52.950.447.650.7

Abbreviations: CARE, Contraceptive and Reproductive Experiences; CTS, California Teachers Study; OC, oral contraceptives.

  • aBMI: at 5 years before breast cancer diagnosis for the CARE Study and at cohort entry for the CTS.