Characteristics of breast cancer cases and population controls
| . | Cases (N = 972), no. (%) . | Controls (N = 1,135), no. (%) . | ||
|---|---|---|---|---|
| Age (y) | ||||
| 20-39 | 67 (7) | 116 (10) | ||
| 40-49 | 238 (24) | 310 (27) | ||
| 50-59 | 355 (37) | 387 (34) | ||
| 60-69 | 312 (32) | 322 (28) | ||
| Education | ||||
| High school or less | 389 (40) | 389 (34) | ||
| Some university or technical school | 332 (34) | 422 (37) | ||
| University graduate | 248 (26) | 323 (28) | ||
| Ethnicity | ||||
| Northern European | 633 (67) | 791 (72) | ||
| Mixed or other European | 151 (16) | 183 (17) | ||
| Non-European | 156 (17) | 132 (12) | ||
| Age at menarche (y) | ||||
| ≤11 | 216 (22) | 212 (19) | ||
| 12 | 253 (26) | 303 (27) | ||
| 13 | 245 (25) | 334 (29) | ||
| ≥14 | 258 (27) | 286 (25) | ||
| Age at first birth (y) | ||||
| <20 | 133 (14) | 114 (10) | ||
| 20-24 | 282 (29) | 360 (32) | ||
| 25-29 | 243 (25) | 322 (28) | ||
| ≥30 | 163 (17) | 193 (17) | ||
| Nulliparous | 151 (16) | 146 (13) | ||
| Number of births | ||||
| None | 151 (16) | 146 (13) | ||
| 1 | 152 (16) | 165 (15) | ||
| 2 | 385 (40) | 444 (39) | ||
| ≥3 | 284 (29) | 379 (33) | ||
| Ever breast-fed | ||||
| No | 503 (52) | 497 (44) | ||
| Yes | 469 (48) | 638 (56) | ||
| Menopausal status | ||||
| Premenopausal | 338 (35) | 464 (41) | ||
| Postmenopausal | 593 (61) | 613 (54) | ||
| Unknown | 41 (4) | 58 (5) | ||
| Hormone replacement ever use | ||||
| No | 339 (35) | 387 (34) | ||
| Yes | 632 (65) | 735 (65) | ||
| Family history of breast cancer* | ||||
| No | 783 (81) | 993 (87) | ||
| Yes | 189 (19) | 142 (13) | ||
| BMI (at age 18) | ||||
| <20 | 432 (45) | 487 (43) | ||
| 20.1-24.9 | 469 (48) | 555 (50) | ||
| 25.0+ | 58 (6) | 79 (7) | ||
| BMI (2 years prior to reference age) | ||||
| <20 | 69 (7) | 80 (7) | ||
| 20.1-24.9 | 401 (41) | 487 (43) | ||
| 25.0-29.9 | 299 (31) | 335 (30) | ||
| 30.0+ | 199 (21) | 225 (20) | ||
| Skin color | ||||
| Fair | 307 (32) | 401 (35) | ||
| Light | 171 (18) | 215 (19) | ||
| Light medium | 365 (38) | 430 (38) | ||
| Dark medium/brown/black | 127 (13) | 89 (8) | ||
| . | Cases (N = 972), no. (%) . | Controls (N = 1,135), no. (%) . | ||
|---|---|---|---|---|
| Age (y) | ||||
| 20-39 | 67 (7) | 116 (10) | ||
| 40-49 | 238 (24) | 310 (27) | ||
| 50-59 | 355 (37) | 387 (34) | ||
| 60-69 | 312 (32) | 322 (28) | ||
| Education | ||||
| High school or less | 389 (40) | 389 (34) | ||
| Some university or technical school | 332 (34) | 422 (37) | ||
| University graduate | 248 (26) | 323 (28) | ||
| Ethnicity | ||||
| Northern European | 633 (67) | 791 (72) | ||
| Mixed or other European | 151 (16) | 183 (17) | ||
| Non-European | 156 (17) | 132 (12) | ||
| Age at menarche (y) | ||||
| ≤11 | 216 (22) | 212 (19) | ||
| 12 | 253 (26) | 303 (27) | ||
| 13 | 245 (25) | 334 (29) | ||
| ≥14 | 258 (27) | 286 (25) | ||
| Age at first birth (y) | ||||
| <20 | 133 (14) | 114 (10) | ||
| 20-24 | 282 (29) | 360 (32) | ||
| 25-29 | 243 (25) | 322 (28) | ||
| ≥30 | 163 (17) | 193 (17) | ||
| Nulliparous | 151 (16) | 146 (13) | ||
| Number of births | ||||
| None | 151 (16) | 146 (13) | ||
| 1 | 152 (16) | 165 (15) | ||
| 2 | 385 (40) | 444 (39) | ||
| ≥3 | 284 (29) | 379 (33) | ||
| Ever breast-fed | ||||
| No | 503 (52) | 497 (44) | ||
| Yes | 469 (48) | 638 (56) | ||
| Menopausal status | ||||
| Premenopausal | 338 (35) | 464 (41) | ||
| Postmenopausal | 593 (61) | 613 (54) | ||
| Unknown | 41 (4) | 58 (5) | ||
| Hormone replacement ever use | ||||
| No | 339 (35) | 387 (34) | ||
| Yes | 632 (65) | 735 (65) | ||
| Family history of breast cancer* | ||||
| No | 783 (81) | 993 (87) | ||
| Yes | 189 (19) | 142 (13) | ||
| BMI (at age 18) | ||||
| <20 | 432 (45) | 487 (43) | ||
| 20.1-24.9 | 469 (48) | 555 (50) | ||
| 25.0+ | 58 (6) | 79 (7) | ||
| BMI (2 years prior to reference age) | ||||
| <20 | 69 (7) | 80 (7) | ||
| 20.1-24.9 | 401 (41) | 487 (43) | ||
| 25.0-29.9 | 299 (31) | 335 (30) | ||
| 30.0+ | 199 (21) | 225 (20) | ||
| Skin color | ||||
| Fair | 307 (32) | 401 (35) | ||
| Light | 171 (18) | 215 (19) | ||
| Light medium | 365 (38) | 430 (38) | ||
| Dark medium/brown/black | 127 (13) | 89 (8) | ||
Family history defined as breast cancer in mother, sister, or daughter.