Table 1.
Summary of Baseline Characteristics of Patients With Brain Metastases as Compared to Patients Without Brain Metastases
| Brain Metastasis (N = 42 047) | No Brain Metastasis (N = 2 056 647) | P | |
|---|---|---|---|
| Age, mean (standard deviation) | 64.99 (12.02) | 64.22 (14.50) | <.001a |
| Sex | |||
| Female | 19 989 (47.5%) | 1 040 294 (51.6%) | <.001b |
| Male | 22 058 (52.5%) | 1 016 353 (49.4%) | |
| Year of diagnosis | |||
| 2010 | 6699 (15.9%) | 334 313 (16.3%) | |
| 2011 | 6734 (16.0%) | 339 201 (16.5%) | |
| 2012 | 6961 (16.6%) | 339 801 (16.5%) | <.001b |
| 2013 | 7114 (16.9%) | 342 544 (16.7%) | |
| 2014 | 7306 (17.4%) | 347 392 (16.9%) | |
| 2015 | 7233 (17.2%) | 353 395 (17.2%) | |
| Race | |||
| American Indian/ Alaska Native | 249 (0.6%) | 12 127 (0.6%) | |
| Asian or Pacific Islander | 2998 (7.1%) | 137 248 (6.7%) | <.001b |
| Black | 5034 (12.0%) | 221 846 (10.8%) | |
| White | 33 692 (80.1%) | 1 658 355 (80.6%) | |
| Unknown | 74 (0.2%) | 27 071 (1.3%) | |
| T-stage | |||
| T0 | 1201 (2.9%) | 6567 (0.3%) | |
| T1 | 4446 (10.6%) | 811 899 (39.5%) | |
| T2 | 9144 (21.7%) | 478 510 (23.3%) | <.001b |
| T3 | 8348 (19.9%) | 337 164 (16.4%) | |
| T4 | 10 894 (25.9%) | 160 678 (7.8%) | |
| TX | 6999 (16.6%) | 137 323 (6.7%) | |
| Missing | 1015 (2.4%) | 62 048 (3.0%) | |
| Other T | 0 (0%) | 62 458 (3.0%) | |
| N-stage | |||
| N0 | 10 155 (24.2%) | 1 433 217 (69.7%) | |
| N+ | 26 937 (64.1%) | 491 890 (23.9%) | <.001b |
| NX | 3927 (9.3%) | 69 316 (3.4%) | |
| Missing | 1028 (2.4%) | 1370 (0.1%) | |
| M-stage | <.001b | ||
| M1 | 1033 (97.6%) | 293 557 (14.3%) | |
| M0 | 0 (0%) | 1 701 063 (82.7%) | |
| Missing | 1014 (2.4%) | 62 027 (3.0%) |
aTwo-sample t-tests.
bChi-squared tests.