| Cases (n = 1,316) | Controls (n = 1,568) | P value | ||
---|---|---|---|---|---|
 | n | %a | n | %a |  |
Age (years) | Â | Â | Â | Â | Â |
 35–44 | 20 | 2 | 25 | 2 |  |
 45–54 | 199 | 15 | 260 | 17 |  |
 55–64 | 531 | 40 | 625 | 40 |  |
 65–74 | 407 | 31 | 509 | 33 |  |
 ≥75 | 159 | 12 | 149 | 10 |  |
Race/ethnicity | Â | Â | Â | Â | Â |
 Hispanic | 614 | 47 | 804 | 51 |  |
 Non-Hispanic White | 389 | 30 | 399 | 26 |  |
 African American | 313 | 24 | 365 | 23 |  |
Joint ER/PR status | Â | Â | Â | Â | Â |
 ER+PR+ | 714 | 54 |  |  |  |
 ER+PR- | 168 | 13 |  |  |  |
 ER-PR+ | 21 | 2 |  |  |  |
 ER-PR- | 204 | 16 |  |  |  |
 Missing | 209 | 16 |  |  |  |
Menopausal hormone therapy use | Â | Â | Â | Â | <0.01 |
 Never | 517 | 39 | 644 | 41 |  |
 Former | 284 | 22 | 692 | 44 |  |
 Current | 498 | 38 | 214 | 14 |  |
 Missing | 17 | 1 | 18 | 1 |  |
Place of birth | Â | Â | Â | Â | <0.01 |
 U.S.-bornb | 1,014 | 77 | 1,036 | 66 |  |
 Foreign-born | 302 | 23 | 532 | 34 |  |
Education (years) | Â | Â | Â | Â | <0.01 |
 Some high school or less | 398 | 30 | 600 | 38 |  |
 High school or vocational/technical school graduate | 373 | 28 | 426 | 27 |  |
 Some college | 297 | 23 | 297 | 19 |  |
 College graduate | 248 | 19 | 245 | 16 |  |
Family history of breast cancer in first-degree relatives | Â | Â | Â | Â | <0.01 |
 No | 1,089 | 83 | 1,371 | 87 |  |
 Yes | 227 | 17 | 197 | 13 |  |
Personal history of biopsy-confirmed benign breast disease | Â | Â | Â | Â | 0.01 |
 No | 1,016 | 77 | 1,274 | 81 |  |
 Yes | 300 | 23 | 294 | 19 |  |
Age at menarche | Â | Â | Â | Â | <0.01 |
 ≤11 | 304 | 23 | 327 | 21 |  |
 12 | 349 | 27 | 356 | 23 |  |
 13 | 319 | 24 | 387 | 25 |  |
 ≥14 | 344 | 26 | 498 | 32 |  |
Parity | Â | Â | Â | Â | <0.01 |
 Nulliparous | 169 | 13 | 145 | 9 |  |
 Parous | 1,147 | 87 | 1,423 | 91 |  |
Number of full-term pregnancies, parous women | Â | Â | Â | Â | <0.01 |
 1 | 162 | 14 | 177 | 12 |  |
 2 | 309 | 27 | 303 | 21 |  |
 3 | 263 | 23 | 349 | 25 |  |
 ≥4 | 413 | 36 | 594 | 42 |  |
Age at first full-term pregnancy (years), parous women | Â | Â | Â | Â | <0.01 |
 ≤19 | 302 | 26 | 415 | 29 |  |
 20–24 | 462 | 40 | 564 | 40 |  |
 25–29 | 235 | 21 | 298 | 21 |  |
 ≥30 | 148 | 13 | 146 | 10 |  |
Lifetime breast-feeding (months), parous women | Â | Â | Â | Â | <0.01 |
 0 | 541 | 47 | 547 | 38 |  |
 ≤ 6 | 250 | 22 | 294 | 21 |  |
 7–12 | 97 | 8 | 148 | 10 |  |
 13–24 | 126 | 11 | 184 | 13 |  |
 ≥25 | 133 | 12 | 250 | 18 |  |
Lifetime physical activityc (hours/week) | Â | Â | Â | Â | 0.04 |
 ≤ 6.9 | 376 | 29 | 391 | 25 |  |
 7.0-14.1 | 342 | 26 | 390 | 25 |  |
 14.2-25.4 | 291 | 22 | 403 | 26 |  |
 ≥25.5 | 307 | 23 | 384 | 25 |  |
Alcohol consumptiond,e (g/day) | Â | Â | Â | Â | <0.01 |
 0 | 763 | 58 | 975 | 62 |  |
 0.1-4.9 | 262 | 20 | 312 | 20 |  |
 5.0-9.9 | 68 | 5 | 91 | 6 |  |
 10.0-19.9 | 115 | 9 | 107 | 7 |  |
 ≥20 | 108 | 8 | 83 | 5 |  |
Total caloric intakec,d,e (kcal/day) | Â | Â | Â | Â | 0.05 |
 ≤ 1362 | 287 | 22 | 394 | 25 |  |
 1363–1798 | 343 | 26 | 385 | 25 |  |
 1799–2435 | 379 | 29 | 398 | 25 |  |
 ≥2436 | 307 | 23 | 391 | 25 |  |