Table 1.
Demographics and clinicopathologic characteristics of the cohort with breast cancer lung metastatic.
| Variables | Total Cohort (n = 3916) | Training Cohort (n = 2611) | Validation Cohort (n = 1305) | |||
|---|---|---|---|---|---|---|
| No | % | No | % | No | % | |
| Age | ||||||
| ≤50 | 788 | 20.1 | 516 | 19.8 | 272 | 20.8 |
| 51–65 | 1556 | 39.7 | 1045 | 40.0 | 511 | 39.2 |
| >65 | 1572 | 40.1 | 1050 | 40.2 | 522 | 40.0 |
| Gender | ||||||
| Female | 3853 | 98.4 | 2573 | 98.5 | 1280 | 98.1 |
| Male | 63 | 1.6 | 38 | 1.5 | 25 | 1.9 |
| Marital status | ||||||
| Married | 1613 | 41.2 | 1073 | 41.1 | 540 | 41.4 |
| Unmarried | 2303 | 58.8 | 1538 | 58.9 | 765 | 58.6 |
| Insurance | ||||||
| No | 228 | 5.8 | 146 | 5.6 | 82 | 6.3 |
| Yes | 3688 | 94.2 | 2465 | 94.4 | 1223 | 93.7 |
| Race | ||||||
| White | 2830 | 72.3 | 1886 | 72.2 | 944 | 72.3 |
| Black | 729 | 18.6 | 469 | 18.0 | 260 | 20.0 |
| Other | 357 | 9.1 | 256 | 9.8 | 101 | 7.7 |
| Grade | ||||||
| I/II | 1729 | 44.2 | 1149 | 44.0 | 580 | 44.4 |
| III/IV | 2187 | 55.8 | 1462 | 56.0 | 725 | 55.6 |
| T stage | ||||||
| T1 | 433 | 11.1 | 294 | 11.3 | 139 | 10.7 |
| T2 | 1140 | 29.1 | 779 | 29.8 | 361 | 27.7 |
| T3 | 691 | 17.6 | 452 | 17.3 | 239 | 18.3 |
| T4 | 1652 | 42.2 | 1086 | 41.6 | 566 | 43.3 |
| N stage | ||||||
| N0 | 861 | 22.0 | 580 | 22.2 | 281 | 21.5 |
| N1 | 1931 | 49.3 | 1279 | 49.0 | 652 | 50.0 |
| N2 | 516 | 13.2 | 336 | 12.9 | 180 | 13.8 |
| N3 | 608 | 15.5 | 416 | 15.9 | 192 | 14.7 |
| Surgery | ||||||
| No | 2719 | 69.4 | 1807 | 69.2 | 912 | 69.9 |
| Yes | 1197 | 30.6 | 804 | 30.8 | 393 | 30.1 |
| Chemotherapy | ||||||
| No | 1462 | 37.3 | 965 | 37.0 | 497 | 38.1 |
| Yes | 2454 | 62.7 | 1646 | 63.0 | 808 | 61.9 |
| Radiation | ||||||
| No | 1689 | 43.1 | 754 | 28.9 | 935 | 71.6 |
| Yes | 2227 | 56.9 | 1857 | 71.1 | 370 | 28.4 |
| Bone metastatic | ||||||
| No | 1829 | 46.7 | 1244 | 47.6 | 585 | 44.8 |
| Yes | 2087 | 53.3 | 1367 | 52.4 | 720 | 55.2 |
| Brain metastatic | ||||||
| No | 3559 | 90.9 | 2370 | 90.8 | 1189 | 91.1 |
| Yes | 357 | 9.1 | 241 | 9.2 | 116 | 8.9 |
| Liver metastatic | ||||||
| No | 2872 | 73.3 | 1921 | 73.6 | 951 | 72.9 |
| Yes | 1044 | 26.7 | 690 | 26.4 | 354 | 27.1 |
| ER | ||||||
| Negative | 1194 | 30.5 | 803 | 30.8 | 391 | 30.0 |
| Positive | 2722 | 69.5 | 1808 | 69.2 | 914 | 70.0 |
| PR | ||||||
| Negative | 1705 | 43.5 | 1132 | 43.4 | 573 | 43.9 |
| Positive | 2211 | 56.5 | 1479 | 56.6 | 732 | 56.1 |
| HER2 | ||||||
| Negative | 2770 | 70.7 | 1824 | 69.9 | 946 | 72.5 |
| Positive | 1146 | 29.3 | 787 | 30.1 | 359 | 27.5 |
| OS (months) | 20.94 | 20.9 | 20.9 | |||
| CSS (months) | 21.01 | 21.0 | 20.9 | |||
For marital status, unmarried consists of single, divorced, separated, and widowed. For race, ‘other’ includes American Indian, AK Native, Asian, and Pacific Islander. ER, estrogen receptor. PR, progesterone receptor. HER2, human epidermal growth factor receptor 2.