Table 1.

Selected characteristics of invasive breast cancer cases and non-cases at time of enrollment

Non-casesaCasesb
N = 46,381 (97%)N = 1,255 (3%)
n (%)n (%)
Age at interview, y
 60+15,091 (33)518 (41)
 55–599,240 (20)253 (20)
 50–549,011 (19)201 (16)
 <5013,039 (28)283 (23)
Race/ethnicity
 Non–Hispanic White38,577 (83)1,100 (88)
 Black4,388 (9)72 (6)
 Hispanic2,199 (5)49 (4)
 Other1,205 (3)33 (3)
Education at interview
 College/postgrad30,323 (65)854 (68)
 Some college8,992 (19)218 (17)
 High school grad/GED6,520 (14)174 (14)
 <High school grad535 (1)8 (1)
Household income at interview
 $100,000+/y15,061 (34)416 (35)
 $50,000 to <$100,000/y18,162 (41)479 (40)
 $<50,000/y11,397 (26)298 (25)
Parity
 3+ births14,134 (30)372 (30)
 2 births17,124 (37)458 (36)
 1 birth6,693 (14)203 (16)
 Nulliparous8,398 (18)222 (18)
Age at first-term pregnancy,c y
 28+10,095 (28)302 (30)
 24 to <289,706 (27)262 (26)
 21 to <248,511 (23)227 (23)
 <218,162 (22)204 (21)

NOTE: Differences in the total numbers of cases and controls are due to missing values.

  • aNoninvasive cases were censored at the date of diagnosis.

  • bExcluding 25 cases missing information on date of diagnosis date.

  • cAmong parous women only.