Table 3.
Association between HR status of first breast cancer and CBC risk, by time since diagnosis
| Time <5 years to CBC | Time 5 to <10 years to CBC | Time ≥10 years to CBC | |||||
|---|---|---|---|---|---|---|---|
| N (cases/controls) | RRa (95% CI) | N (cases/controls) | RRa (95% CI) | N (cases/controls) | RRa (95% CI) | P-heterogeneity | |
| All women, tumor status at first diagnosis | |||||||
| ER status | |||||||
| Positive | 306/585 | 1.0 (ref.) | 293/440 | 1.0 (ref.) | 198/229 | 1.0 (ref.) | |
| Negative | 186/241 | 1.4 (1.1, 1.9) | 186/209 | 1.3 (1.0, 1.8) | 95/111 | 1.0 (0.7, 1.5) | 0.37 |
| Other/unknownb | 94/160 | 95/155 | 68/82 | ||||
| PR status | |||||||
| Positive | 262/477 | 1.0 (ref.) | 249/395 | 1.0 (ref.) | 176/211 | 1.0 (ref.) | |
| Negative | 183/238 | 1.3 (1.0, 1.8) | 169/203 | 1.3 (1.0, 1.8) | 90/108 | 0.9 (0.6, 1.4) | 0.26 |
| Other/unknownb | 141/271 | 156/206 | 95/103 | ||||
| Joint ER/PR status | |||||||
| ER+/PR+ | 239/423 | 1.0 (ref.) | 219/351 | 1.0 (ref.) | 163/184 | 1.0 (ref.) | |
| ER+/PR- | 38/68 | 1.0 (0.6, 1.6) | 31/48 | 1.2 (0.7, 2.2) | 16/26 | 0.6 (0.3, 1.3) | |
| ER-/PR- | 145/166 | 1.5 (1.1, 2.1) | 136/145 | 1.5 (1.0, 2.0) | 71/76 | 1.1 (0.7, 1.6) | 0.45 |
| Other/unknownb,c | 164/329 | 188/260 | 111/136 | ||||
| Women who did not receive tamoxifen treatment for first diagnosis, tumor status at first diagnosis | |||||||
| ER status | |||||||
| Positive | 169/290 | 1.0 (ref.) | 141/196 | 1.0 (ref.) | 97/108 | 1.0 (ref.) | |
| Negative | 169/212 | 1.4 (0.9, 2.1) | 166/173 | 1.4 (0.9, 2.0) | 87/92 | 1.1 (0.7, 1.9) | 0.77 |
| Other/unknownb | 85/142 | 80/135 | 60/77 | ||||
| PR status | |||||||
| Positive | 135/222 | 1.0 (ref.) | 117/165 | 1.0 (ref.) | 84/102 | 1.0 (ref.) | |
| Negative | 159/187 | 1.4 (0.9, 2.1) | 145/160 | 1.3 (0.8, 2.0) | 82/82 | 1.3 (0.7, 2.2) | 0.97 |
| Other/unknownb | 129/235 | 125/179 | 78/93 | ||||
| Joint ER/PR status | |||||||
| ER+/PR+ | 121/185 | 1.0 (ref.) | 97/136 | 1.0 (ref.) | 75/83 | 1.0 (ref.) | |
| ER+/PR- | 24/31 | 1.3 (0.6, 2.7) | 16/26 | 0.7 (0.3, 2.0) | 12/13 | 1.6 (0.4, 6.2) | |
| ER-/PR- | 135/152 | 1.4 (0.9, 2.3) | 127/125 | 1.5 (0.9, 2.4) | 67/64 | 1.3 (0.7, 2.4) | 0.84 |
| Other/unknownb,c | 143/276 | 147/217 | 90/117 | ||||
Abbreviations: HR hormone receptor, CBC contralateral breast cancer, RR risk ratio, CI confidence interval, N number, ER estrogen receptor, PR progesterone receptor
aAdjusted for age at first breast cancer diagnosis, first-degree family history of breast cancer, histologic assessment, stage, menopausal status, age at menarche, parity, radiation, chemotherapy and hormone therapy at first breast cancer diagnosis. b“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. cIncludes tumors classified as ER-/PR+