Characteristics of study participants: comparison of cases and controls for all study participants and for subset whose mothers were interviewed and comparison of study participants by whether mother was interviewed
| . | All study participants . | . | Subset with data from mothers . | . | All study participants . | . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | No. (%) cases (n = 597) . | No. (%) controls (n = 966) . | No. (%) cases (n = 99) . | No. (%) controls (n = 156) . | No. (%) mothers interviewed (n = 255) . | No. (%) mothers not interviewed (n = 1,308) . | ||||||
| Age at diagnosis* | ||||||||||||
| 20-39 | 137 (23) | 270 (28) | 35 (36) | 75 (48) | 110 (43) | 297 (23) | ||||||
| 40-44 | 108 (18) | 191 (20) | 32 (32) | 36 (23) | 68 (27) | 231 (18) | ||||||
| 45-49 | 154 (26) | 190 (20) | 19 (19) | 29 (19) | 48 (19) | 296 (23) | ||||||
| ≥50 | 198 (33) | 315 (33) | 13 (13) | 16 (10) | 29 (11) | 484 (37) | ||||||
| P = 0.05 | P = 0.15 | P < 0.0001 | ||||||||||
| Race | ||||||||||||
| Chinese | 164 (27) | 288 (30) | 26 (26) | 51 (33) | 77 (30) | 375 (29) | ||||||
| Japanese | 239 (40) | 395 (41) | 53 (54) | 82 (52) | 135 (53) | 499 (38) | ||||||
| Filipino | 194 (33) | 283 (29) | 20 (20) | 23 (15) | 43 (17) | 434 (33) | ||||||
| P = 0.17 | P = 0.17 | P = 0.0007 | ||||||||||
| Study center | ||||||||||||
| Hawaii | 213 (36) | 379 (39) | 38 (39) | 84 (54) | 122 (48) | 470 (36) | ||||||
| Los Angeles | 215 (36) | 274 (28) | 28 (28) | 23 (15) | 51 (20) | 438 (34) | ||||||
| San Francisco-Oakland | 169 (28) | 313 (32) | 33 (33) | 49 (31) | 82 (32) | 400 (31) | ||||||
| P = 0.90 | P = 0.12 | P = 0.07 | ||||||||||
| Parity | ||||||||||||
| Nulliparous | 145 (25) | 148 (15) | 38 (38) | 24 (15) | 62 (24) | 231 (18) | ||||||
| 1 live birth | 85 (14) | 141 (15) | 19 (19) | 34 (22) | 53 (21) | 173 (13) | ||||||
| 2-3 live births | 288 (49) | 481 (50) | 37 (38) | 76 (49) | 113 (44) | 656 (51) | ||||||
| ≥4 live births | 73 (12) | 188 (20) | 5 (5) | 22 (14) | 27 (11) | 234 (18) | ||||||
| P < 0.0001 | P < 0.0001 | P = 0.31† | ||||||||||
| Age at first live birth | ||||||||||||
| Nulliparous | 145 (25) | 148 (15) | 38 (38) | 24 (15) | 62 (24) | 231 (18) | ||||||
| ≤20 | 30 (5) | 96 (10) | 2 (2) | 18 (12) | 20 (8) | 106 (8) | ||||||
| 21-30 | 314 (53) | 583 (61) | 39 (40) | 92 (59) | 131 (51) | 766 (59) | ||||||
| ≥31 | 101 (17) | 128 (13) | 20 (20) | 22 (14) | 42 (17) | 187 (15) | ||||||
| P = 0.06 | P = 0.02 | P = 0.67† | ||||||||||
| Menopausal status at diagnosis | ||||||||||||
| Premenopausal | 438 (74) | 684 (71) | 88 (89) | 136 (87) | 224 (88) | 898 (69) | ||||||
| Postmenopausal | 151 (26) | 277 (29) | 11 (11) | 20 (13) | 31 (12) | 397 (31) | ||||||
| P = 0.17 | P = 0.68 | P = 0.92† | ||||||||||
| Age at menarche | ||||||||||||
| ≤11 | 105 (18) | 160 (17) | 19 (19) | 48 (31) | 67 (26) | 198 (15) | ||||||
| 12-13 | 284 (48) | 457 (48) | 60 (61) | 82 (53) | 142 (56) | 599 (46) | ||||||
| 14-15 | 138 (23) | 225 (23) | 16 (16) | 21 (13) | 37 (15) | 326 (25) | ||||||
| ≥16 | 63 (11) | 117 (12) | 4 (4) | 4 (3) | 8 (3) | 172 (13) | ||||||
| P = 0.36 | P = 0.07 | P = 0.004† | ||||||||||
| Family history of breast cancer | ||||||||||||
| First- or second-degree relative | 117 (20) | 92 (10) | 18 (18) | 22 (14) | 40 (16) | 169 (13) | ||||||
| No relatives | 480 (80) | 874 (90) | 81 (82) | 134 (86) | 215 (84) | 1139 (87) | ||||||
| P < 0.0001 | P = 0.38 | P = 0.67† | ||||||||||
| Personal history of benign breast disease | ||||||||||||
| Yes | 104 (18) | 98 (10) | 23 (23) | 22 (14) | 45 (18) | 162 (13) | ||||||
| No | 469 (82) | 840 (90) | 76 (77) | 134 (86) | 210 (82) | 1134 (87) | ||||||
| P < 0.0001 | P = 0.06 | P = 0.05† | ||||||||||
| . | All study participants . | . | Subset with data from mothers . | . | All study participants . | . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | No. (%) cases (n = 597) . | No. (%) controls (n = 966) . | No. (%) cases (n = 99) . | No. (%) controls (n = 156) . | No. (%) mothers interviewed (n = 255) . | No. (%) mothers not interviewed (n = 1,308) . | ||||||
| Age at diagnosis* | ||||||||||||
| 20-39 | 137 (23) | 270 (28) | 35 (36) | 75 (48) | 110 (43) | 297 (23) | ||||||
| 40-44 | 108 (18) | 191 (20) | 32 (32) | 36 (23) | 68 (27) | 231 (18) | ||||||
| 45-49 | 154 (26) | 190 (20) | 19 (19) | 29 (19) | 48 (19) | 296 (23) | ||||||
| ≥50 | 198 (33) | 315 (33) | 13 (13) | 16 (10) | 29 (11) | 484 (37) | ||||||
| P = 0.05 | P = 0.15 | P < 0.0001 | ||||||||||
| Race | ||||||||||||
| Chinese | 164 (27) | 288 (30) | 26 (26) | 51 (33) | 77 (30) | 375 (29) | ||||||
| Japanese | 239 (40) | 395 (41) | 53 (54) | 82 (52) | 135 (53) | 499 (38) | ||||||
| Filipino | 194 (33) | 283 (29) | 20 (20) | 23 (15) | 43 (17) | 434 (33) | ||||||
| P = 0.17 | P = 0.17 | P = 0.0007 | ||||||||||
| Study center | ||||||||||||
| Hawaii | 213 (36) | 379 (39) | 38 (39) | 84 (54) | 122 (48) | 470 (36) | ||||||
| Los Angeles | 215 (36) | 274 (28) | 28 (28) | 23 (15) | 51 (20) | 438 (34) | ||||||
| San Francisco-Oakland | 169 (28) | 313 (32) | 33 (33) | 49 (31) | 82 (32) | 400 (31) | ||||||
| P = 0.90 | P = 0.12 | P = 0.07 | ||||||||||
| Parity | ||||||||||||
| Nulliparous | 145 (25) | 148 (15) | 38 (38) | 24 (15) | 62 (24) | 231 (18) | ||||||
| 1 live birth | 85 (14) | 141 (15) | 19 (19) | 34 (22) | 53 (21) | 173 (13) | ||||||
| 2-3 live births | 288 (49) | 481 (50) | 37 (38) | 76 (49) | 113 (44) | 656 (51) | ||||||
| ≥4 live births | 73 (12) | 188 (20) | 5 (5) | 22 (14) | 27 (11) | 234 (18) | ||||||
| P < 0.0001 | P < 0.0001 | P = 0.31† | ||||||||||
| Age at first live birth | ||||||||||||
| Nulliparous | 145 (25) | 148 (15) | 38 (38) | 24 (15) | 62 (24) | 231 (18) | ||||||
| ≤20 | 30 (5) | 96 (10) | 2 (2) | 18 (12) | 20 (8) | 106 (8) | ||||||
| 21-30 | 314 (53) | 583 (61) | 39 (40) | 92 (59) | 131 (51) | 766 (59) | ||||||
| ≥31 | 101 (17) | 128 (13) | 20 (20) | 22 (14) | 42 (17) | 187 (15) | ||||||
| P = 0.06 | P = 0.02 | P = 0.67† | ||||||||||
| Menopausal status at diagnosis | ||||||||||||
| Premenopausal | 438 (74) | 684 (71) | 88 (89) | 136 (87) | 224 (88) | 898 (69) | ||||||
| Postmenopausal | 151 (26) | 277 (29) | 11 (11) | 20 (13) | 31 (12) | 397 (31) | ||||||
| P = 0.17 | P = 0.68 | P = 0.92† | ||||||||||
| Age at menarche | ||||||||||||
| ≤11 | 105 (18) | 160 (17) | 19 (19) | 48 (31) | 67 (26) | 198 (15) | ||||||
| 12-13 | 284 (48) | 457 (48) | 60 (61) | 82 (53) | 142 (56) | 599 (46) | ||||||
| 14-15 | 138 (23) | 225 (23) | 16 (16) | 21 (13) | 37 (15) | 326 (25) | ||||||
| ≥16 | 63 (11) | 117 (12) | 4 (4) | 4 (3) | 8 (3) | 172 (13) | ||||||
| P = 0.36 | P = 0.07 | P = 0.004† | ||||||||||
| Family history of breast cancer | ||||||||||||
| First- or second-degree relative | 117 (20) | 92 (10) | 18 (18) | 22 (14) | 40 (16) | 169 (13) | ||||||
| No relatives | 480 (80) | 874 (90) | 81 (82) | 134 (86) | 215 (84) | 1139 (87) | ||||||
| P < 0.0001 | P = 0.38 | P = 0.67† | ||||||||||
| Personal history of benign breast disease | ||||||||||||
| Yes | 104 (18) | 98 (10) | 23 (23) | 22 (14) | 45 (18) | 162 (13) | ||||||
| No | 469 (82) | 840 (90) | 76 (77) | 134 (86) | 210 (82) | 1134 (87) | ||||||
| P < 0.0001 | P = 0.06 | P = 0.05† | ||||||||||
An age comparable with the age at diagnosis of breast cancer was assigned to each of the controls based on the ages at diagnosis of the frequency-matched cases (2).
P values are adjusted for subject's age and place of birth, as these variables reflect the basis for identifying the mothers eligible for interview.