Table 2.
Hazard ratios (HRs) comparing cancer mortality after the second primary cancer (SPC) in breast cancer survivors to cancer mortality after the first primary cancer (FPC) for different types of cancer.
| Number of cases | Person-months | Number of deaths | HR (95% CI)a | |
|---|---|---|---|---|
| Breast cancer | 13,903 | 903004.5 | 1815 | 1.00 (Reference) |
| BC + BC | 13,931 | 825131.5 | 3198 | 1.82 (1.71, 1.94) |
| ER-positive BC + BC | 9069 | 534883.5 | 1842 | 1.77 (1.65, 1.90) |
| ER-negative BC + BC | 3184 | 183208 | 889 | 1.98 (1.81, 2.17) |
| Lung cancer | 4900 | 121576 | 3283 | 1.00 (Reference) |
| BC + Lung cancer | 4850 | 120105 | 3339 | 0.95 (0.91, 1.00) |
| ER-positive BC + Lung cancer | 3414 | 87507 | 2260 | 0.92 (0.87, 0.97) |
| ER-negative BC + Lung cancer | 880 | 20057.5 | 659 | 1.10 (1.01, 1.20) |
| Colorectal cancer | 3424 | 181289.5 | 1079 | 1.00 (Reference) |
| BC + Colorectal cancer | 3351 | 173083 | 1171 | 1.11 (1.02, 1.21) |
| ER-positive BC + Colorectal cancer | 2466 | 128772 | 838 | 1.07 (0.98, 1.18) |
| ER-negative BC + Colorectal cancer | 515 | 24758.5 | 186 | 1.17 (1.00, 1.36) |
| Uterine cancer | 2335 | 147537.5 | 433 | 1.00 (Reference) |
| BC + Uterine cancer | 2392 | 144851.5 | 669 | 1.40 (1.24, 1.58) |
| ER-positive BC + Uterine cancer | 1752 | 104264 | 507 | 1.43 (1.26, 1.63) |
| ER-negative BC + Uterine cancer | 380 | 23595 | 88 | 1.30 (1.03, 1.64) |
| Lymphoma | 1202 | 60396.5 | 391 | 1.00 (Reference) |
| BC + Lymphoma | 1191 | 55653 | 448 | 1.15 (1.00, 1.32) |
| ER-positive BC + Lymphoma | 921 | 42804.5 | 335 | 1.09 (0.95, 1.27) |
| ER-negative BC + Lymphoma | 153 | 7048 | 66 | 1.51 (1.16, 1.97) |
| Thyroid cancer | 1237 | 86451.5 | 32 | 1.00 (Reference) |
| BC + Thyroid cancer | 1268 | 85812.5 | 107 | 3.09 (2.06, 4.61) |
| ER-positive BC + Thyroid cancer | 926 | 61235 | 66 | 2.44 (1.59, 3.76) |
| ER-negative BC + Thyroid cancer | 217 | 15688 | 24 | 5.05 (2.93, 8.68) |
| Melanoma | 1240 | 81894.5 | 106 | 1.00 (Reference) |
| BC + Melanoma | 1261 | 83854 | 181 | 1.51 (1.18, 1.92) |
| ER-positive BC + Melanoma | 956 | 62150.5 | 129 | 1.34 (1.03, 1.74) |
| ER-negative BC + Melanoma | 197 | 13689.5 | 30 | 2.06 (1.36, 3.10) |
| Ovarian cancer | 1113 | 49886 | 631 | 1.00 (Reference) |
| BC + Ovarian cancer | 1095 | 48083.5 | 667 | 1.02 (0.92, 1.14) |
| ER-positive BC + Ovarian cancer | 684 | 28563 | 437 | 1.03 (0.91, 1.16) |
| ER-negative BC + Ovarian cancer | 275 | 13461.5 | 145 | 1.00 (0.83, 1.20) |
| Pancreatic cancer | 1093 | 12472.5 | 959 | 1.00 (Reference) |
| BC + Pancreatic cancer | 1130 | 13716 | 999 | 0.97 (0.89, 1.06) |
| ER-positive BC + Pancreatic cancer | 832 | 9953 | 742 | 0.97 (0.88, 1.06) |
| ER-negative BC + Pancreatic cancer | 161 | 2012 | 139 | 0.99 (0.82, 1.18) |
| Leukemia | 1265 | 53258 | 576 | 1.00 (Reference) |
| BC + Leukemia | 1243 | 38144 | 753 | 1.53 (1.37, 1.70) |
| ER-positive BC + Leukemia | 900 | 28404.5 | 533 | 1.45 (1.29, 1.63) |
| ER-negative BC + Leukemia | 228 | 6510.5 | 144 | 1.79 (1.49, 2.16) |
Estrogen receptor (ER) status is missing for some breast cancers.
HRs for overall, ER-positive, and ER-negative breast cancer survivors are presented separately.
FPC first primary cancer, SPC second primary cancer, HR hazard ratio, CI confidence interval, BC breast cancer, ER estrogen receptor.
aModels adjusted for race, year of diagnosis, age at diagnosis, tumor stage, and treatments (surgery, chemotherapy, and radiotherapy). For breast cancer, we further adjusted for ER status. For leukemia, we omitted surgery (it was not a treatment option) and tumor stage (all leukemia were distant stage).