Table 1.
Distribution of demographic and density characteristics among cases and age-matched controls with mammographic data in the Women At Risk registry, Columbia University Medical Center
| Cases, N = 85, N (%) | Controls, N = 85, N (%) | |
|---|---|---|
| Median age at diagnosis1 | 54.5 years (range 37–84) | 54.0 years (range 36–85) |
| Median age at first mammogram2 | 52.7 years (range 32–77) | 51.5 years (range 29–76) |
| Median time between mammograms (years) | 4.0 (range 1–15) | 4.0 (range 1–14) |
| Median time between 2nd mammogram and cancer Dx (years) | 1.5 (range 0.5–9.4) | NA |
| Density characteristics | ||
| Mean percent density, time 1 (%) | 29.0 (range 3–96) | 29.2 (range 1–84) |
| Mean percent density, time 2 (%) | 25.5 (range 5–59) | 23.7 (range 2–77) |
| Mean change in % density | −2.67 (range −34–16) | −5.35 (range −48–49) |
| Demographic and risk factor characteristics | ||
| Race/Ethnicity | ||
| White | 70 (88) | 71 (91) |
| African American | 2 (3) | 1 (1) |
| Hispanic | 4 (5) | 3 (4) |
| Other | 4 (5) | 3 (4) |
| Family history of breast cancer | ||
| Yes | 52 (63) | 60 (75) |
| No | 30 (37) | 20 (25) |
| History of benign breast disease | ||
| Yes | 53 (66) | 63 (75) |
| No | 27 (34) | 21 (25) |
| Alcohol use | ||
| Yes | 39 (62) | 38 (59) |
| No | 24 (38) | 26 (41) |
| BMI | ||
| Average | 24.8±5.2 | 24.8±4.0 |
| Oral contraceptive use | ||
| Never | 43 (61) | 45 (62) |
| Ever | 28 (39) | 27 (38) |
| Menopausal status3 | ||
| Premenopausal | 44 (53) | 42 (50) |
| Postmenopausal | 39 (47) | 42 (50) |
| Parity | ||
| Nulliparous | 23 (27) | 18 (22) |
| 1 or 2 live births | 47 (55) | 47 (56) |
| ≥3 live births | 15 (18) | 18 (22) |
| Among parous women only: | ||
| Age at first birth (mean) | ||
| Average | 27.2 | 27.5 |
| Time since last birth4 | ||
| Average (years) | 27.4 | 30.0 |
| Breastfeeding | ||
| Never | 27 (47) | 34 (51) |
| Ever | 31 (53) | 32 (49) |
1
The age at diagnosis for the controls refers to the age of the controls when their matched case was diagnosed with cancer.
2
Age at first mammo is age at the first mammogram used for density readings in this analysis, NOT the age of the woman at her first ever mammogram.
3
Indicates menopausal status at first mammogram used for density readings.
4
For cases, time since last birth is time between last birth and cancer diagnosis. For controls, time since last birth is time between last birth and the cancer diagnosis of their matched case.