Table 1.
Summary of baseline characteristics for all cancer cases with and without synchronous lung metastasis in the United States from 2010 to 2015.
| Synchronous lung metastasis (N = 100,751) | No synchronous lung metastasis (N = 1,996,258) | P -value | |
|---|---|---|---|
| Age, mean (standard deviation) | 66.8 (14.3) | 64.1 (14.5) | <0.001 |
| Sex | |||
| Female | 48,819 (48.5%) | 1,010,788 (50.6%) | <0.001 |
| Male | 51,932 (51.5%) | 125,649 (49.4%) | |
| Year of diagnosis | |||
| 2010 | 15,202 (15.1%) | 325,629 (16.3%) | <0.001 |
| 2011 | 15.934 (15.8%) | 329,677 (16.5%) | |
| 2012 | 16,819 (16.7%) | 329,712 (16.5%) | |
| 2013 | 17,331 (17.2%) | 332,026 (16.6%) | |
| 2014 | 17,690 (17.6%) | 336,711 (16.9%) | |
| 2015 | 17,775 (17.6%) | 342,503 (17.2%) | |
| Presence of bone, brain or liver metastasis at diagnosis | |||
| Yes | 54,937 (54.5%) | 164,491 (8.2%) | <0.001 |
| No | 45,814 (45.5%) | 1,831,767 (91.8%) | |
| Race | |||
| American Indian/Alaska Native | 792 (0.8%) | 11,573 (0.6%) | <0.001 |
| Asian or Pacific Islander | 7,953 (7.9%) | 132,326 (6.6%) | |
| Black | 13,202 (13.1%) | 213,513 (10.7%) | |
| White | 78,589 (78.0%) | 1,611,906 (80.7%) | |
| Unknown | 215 (0.2%) | 26,940 (1.3%) | |
| T-Stage | |||
| T0 | 1,671 (1.7%) | 6,045 (0.3%) | <0.001 |
| T1 | 7,979 (7.9%) | 808,117 (40.5%) | |
| T2 | 13,431 (13.3%) | 473,803 (23.7%) | |
| T3 | 24,682 (24.5%) | 320,577 (16.1%) | |
| T4 | 29,894 (29.7%) | 141,626 (7.1%) | |
| TX | 19,045 (18.9%) | 124,536 (6.2%) | |
| Other T | 0 (0%) | 62,460 (3.1%) | |
| Missing | 4,409 (4.0%) | 59,094 (3.0%) | |
| N-Stage | |||
| N0 | 30,912 (30.7%) | 1,411,811 (70.7%) | <0.001 |
| N+ | 53,580 (53.2%) | 464,279 (23.3%) | |
| NX | 12,103 (12.0%) | 60,992 (3.1%) | |
| Missing | 4,156 (4.1%) | 59,176 (3.0%) | |
| M-Stage | |||
| M1 | 96,693 (96.0%) | 237,074 (11.9%) | |
| Other M-Stage | 12 (<0.1%) | 1,700,109 (85.2%) | |
| Missing | 4,046 (4.0%) | 59,075 (3.0%) | |
| Survival duration missing | |||
| No | 100,584 (99.8%) | 1,995,011 (99.9%) | <0.001 |
| Yes | 167 (0.2%) | 1,247 (<0.1%) | |
| Median follow-up duration (months, 95% confidence interval) | 33 (32–33) | 34 (34–34) | 0.01 |
P-values represent results from t-tests, chi-squared tests or log-rank tests for continuous, categorical and time to event variables, respectively, where appropriate. T-Stage, N-Stage, and M-Stage represent those from the American Joint Committee on Cancer 7th Edition Staging Manual.