Table 5.
Association between first breast cancer HR status and subtype-specific CBC, among known BRCA1/2 mutation non-carriers
| Overall CBC | ER+/PR+ CBC | ER+/PR- CBC | ER-/PR- CBC | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N (cases/controls) | RRa (95% CI) | RRb (95% CI) | N (cases/controls) | RRa (95% CI) | RRb (95% CI) | N (cases/controls) | RRa (95% CI) | RRb (95% CI) | N (cases/controls) | RRa (95% CI) | RRb (95% CI) | |
| All women tested for BRCA1/2 mutationsc, tumor status at first diagnosis | ||||||||||||
| ER status | ||||||||||||
| Positive | 336/745 | 1.0 (ref.) | 1.0 (ref.) | 100/179 | 1.0 (ref.) | 1.0 (ref.) | 41/66 | 1.0 (ref.) | 1.0 (ref.) | 26/114 | 1.0 (ref.) | 1.0 (ref.) |
| Negative | 193/338 | 1.4 (1.1, 1.9) | 1.2 (0.9, 1.6) | 22/82 | 0.6 (0.3, 1.2) | 0.7 (0.3, 1.3) | 15/31 | 0.8 (0.3, 2.0) | 0.8 (0.3, 2.0) | 56/56 | 4.6 (2.1, 10.2) | 3.8 (1.6, 8.9) |
| Other/unknownd | 176/315 | 33/44 | 9/30 | 19/32 | ||||||||
| PR status | ||||||||||||
| Positive | 287/615 | 1.0 (ref.) | 1.0 (ref.) | 88/160 | 1.0 (ref.) | 1.0 (ref.) | 35/61 | 1.0 (ref.) | 1.0 (ref.) | 23/95 | 1.0 (ref.) | 1.0 (ref.) |
| Negative | 172/318 | 1.3 (1.0, 1.7) | 1.1 (0.8, 1.5) | 26/86 | 0.8 (0.4, 1.5) | 0.8 (0.5, 1.5) | 16/20 | 2.2 (0.7, 6.8) | 2.2 (0.7, 6.8) | 56/55 | 5.3 (2.3, 12.2) | 6.8 (2.6, 17.6) |
| Other/unknownd | 246/465 | 41/59 | 14/46 | 22/52 | ||||||||
| Joint ER/PR status | ||||||||||||
| ER+/PR+ | 250/536 | 1.0 (ref.) | 1.0 (ref.) | 84/143 | 1.0 (ref.) | 1.0 (ref.) | 29/46 | 1.0 (ref.) | 1.0 (ref.) | 16/86 | 1.0 (ref.) | 1.0 (ref.) |
| ER+/PR- | 38/85 | 1.1 (0.7, 1.7) | 1.1 (0.7, 1.7) | 9/22 | 0.9 (0.3, 2.3) | 0.8 (0.3, 2.2) | 7/4 | 4.9 (0.9, 26.5) | 5.0 (0.9, 27.3) | 8/14 | 4.6 (1.3, 16.4) | 5.3 (1.3, 21.5) |
| ER-/PR- | 132/221 | 1.5 (1.1, 2.1) | 1.2 (0.9, 1.7) | 17/61 | 0.7 (0.3, 1.5) | 0.8 (0.4, 1.6) | 9/16 | 1.2 (0.3, 4.7) | 1.2 (0.3, 4.6) | 48/41 | 7.6 (3.0, 19.5) | 8.9 (3.1, 25.9) |
| Other/unknownd.e | 285/556 | 45/79 | 20/61 | 29/61 | ||||||||
| BRCA1/2 non-carriers only, tumor status at first diagnosis | ||||||||||||
| ER status | ||||||||||||
| Positive | 307/716 | 1.0 (ref.) | 89/178 | 1.0 (ref.) | 39/64 | 1.0 (ref.) | 23/106 | 1.0 (ref.) | ||||
| Negative | 137/304 | 1.2(0.9, 1.7) | 19/70 | 0.7 (0.3, 1.5) | 12/29 | 0.4 (0.1, 1.4) | 33/52 | 3.6 (1.4, 8.9) | ||||
| Other/unknownd | 152/302 | 30/42 | 9/29 | 14/32 | ||||||||
| PR status | ||||||||||||
| Positive | 261/593 | 1.0 (ref.) | 81/159 | 1.0 (ref.) | 32/59 | 1.0 (ref.) | 18/88 | 1.0 (ref.) | ||||
| Negative | 122/286 | 1.0 (0.8, 1.4) | 21/75 | 0.8 (0.4, 1.7) | 14/19 | 1.6 (0.5, 5.3) | 36/52 | 6.7 (2.4, 18.9) | ||||
| Other/unknownd | 213/443 | 36/56 | 14/44 | 16/50 | ||||||||
| Joint ER/PR status | ||||||||||||
| ER+/PR+ | 233/520 | 1.0 (ref.) | 77/143 | 1.0 (ref.) | 27/45 | 1.0 (ref.) | 15/80 | 1.0 (ref.) | ||||
| ER+/PR- | 31/78 | 0.9 (0.5, 1.4) | 7/22 | 0.7 (0.2, 2.0) | 7/4 | 4.4 (0.8, 23.6) | 6/13 | 3.8 (0.8, 17.2) | ||||
| ER-/PR- | 90/197 | 1.2 (0.8, 1.8) | 14/50 | 0.9 (0.4, 2.0) | 7/15 | 0.6 (0.1, 2.8) | 30/39 | 7.7 (2.6, 23.3) | ||||
| Other/unknownd,e | 242/527 | 40/75 | 19/58 | 19/58 | ||||||||
Abbreviations: HR, hormone receptor, CBC contralateral breast cancer, N number, RR risk ratio, CI confidence interval, ER estrogen receptor, PR progesterone receptor. aAdjusted for age at first breast cancer diagnosis, first-degree family history of breast cancer, histologic assessment, menopausal status, age at menarche, parity, radiation, chemotherapy and hormone therapy at first breast cancer diagnosis. bAdjusted for all covariates listed in footnote a and in addition BRCA1 deleterious mutation status. c BRCA1/2 mutation status only assessed among women sampled in the first phase of the Women’s Environmental Cancer and Radiation Epidemiology Study (WECARE) I. d“Other/unknown” category consists of women for whom no laboratory test was given, the test was given and the results were unknown or the test was given and the results were borderline; estimates not reported. eIncludes tumors classified as ER-/PR+