Table 1.
Selected characteristics of invasive breast cancer cases and non-cases at time of enrollment
| Non-Casesa N=46,381 (97%) No. (%) |
Casesb N=1,255 (3%) No. (%) |
||
|---|---|---|---|
| Age at interview | |||
| 60+ years | 15,091 (33) | 518 (41) | |
| 55–59 years | 9,240 (20) | 253 (20) | |
| 50–54 years | 9,011 (19) | 201 (16) | |
| <50 years | 13,039 (28) | 283 (23) | |
| Race/Ethnicity | |||
| Non-Hispanic White | 38,577 (83) | 1,100 (88) | |
| Black | 4,388 (9) | 72 (6) | |
| Hispanic | 2,199 (5) | 49 (4) | |
| Other | 1,205 (3) | 33 (3) | |
| Education at interview | |||
| College/Post Grad | 30,323 (65) | 854 (68) | |
| Some College | 8,992 (19) | 218 (17) | |
| High School Grad/GED | 6,520 (14) | 174 (14) | |
| <High School Grad | 535 (1) | 8 (1) | |
| Household income at interview | |||
| $100,000+/year | 15,061 (34) | 416 (35) | |
| $50,000–<$100,000/year | 18,162 (41) | 479 (40) | |
| $<50,000/year | 11,397 (26) | 298 (25) | |
| Parity | |||
| 3+ births | 14,134 (30) | 372 (30) | |
| 2 births | 17,124 (37) | 458 (36) | |
| 1 birth | 6,693 (14) | 203 (16) | |
| nulliparous | 8,398 (18) | 222 (18) | |
| Age at first term pregnancyc | |||
| 28+ years | 10,095 (28) | 302 (30) | |
| 24–<28 years | 9,706 (27) | 262 (26) | |
| 21–<24 years | 8,511 (23) | 227 (23) | |
| <21 years | 8,162 (22) | 204 (21) | |
a
Non-invasive cases were censored at the date of diagnosis
b
Excluding 25 cases missing information on date of diagnosis date
c
Among parous women only
Note: Differences in the total numbers of cases and controls are due to missing values