Table 2. Five-Year Cumulative Incidence of Breast Cancer by Family History of Breast Cancer, Breast Density, and Age Group, Breast Cancer Surveillance Consortium (BCSC)a.
| Breast Imaging Reporting and Data System Densityb | Incidence (95% CI), Cases per 1000 Women, by First-Degree Family History | |||
|---|---|---|---|---|
| None | Anyc | Relative’s Diagnosis Age <50 y | Relative’s Diagnosis Age ≥50 y | |
| Age 65-74 y | ||||
| a | 10 (9-13) | 17 (13-23) | 16 (9-17) | 13 (9-17) |
| b | 15 (14-16) | 24 (22-27) | 23 (18-30) | 22 (18-26) |
| c or d | 20 (19-22) | 27 (22-30) | 28 (23-35) | 24 (20-28) |
| Age ≥75 y | ||||
| a | 13 (11-16) | 14 (10-19) | 20 (12-30) | 13 (6-19) |
| b | 16 (14-17) | 23 (20-26) | 18 (12-25) | 26 (21-33) |
| c or d | 18 (16-20) | 28 (24-32) | 26 (18-32) | 27 (23-33) |
a
Multivariable models adjusted for BCSC registry, race/ethnicity, postmenopausal hormone therapy use, body mass index, and benign breast disease.
b
a Indicates almost entirely fat; b, scattered fibroglandular; c, heterogeneously dense; d, extremely dense. We grouped c and d categories together because they are not prevalent in older women.
c
Includes observations with missing relative’s age at diagnosis.