Table 1 Baseline characteristics comparison between patients with and without synchronous bone metastasis.
Variables | Total, N = 21,809 (%) | Patients without synchronous BM, N = 16,784 (%) | Patients with synchronous BM, N = 5025 (%) | P value |
|---|---|---|---|---|
Age (years), Median, IQR | 67 (60, 74) | 67 (60, 74) | 66 (59, 73) | < 0.001 |
Race | < 0.001 | |||
White | 18,848 (86) | 14,373 (86) | 4475 (89) | |
Black | 1969 (9) | 1596 (10) | 373 (7) | |
Others | 992 (5) | 815 (5) | 177 (4) | |
Sex | < 0.001 | |||
Male | 10,963 (50) | 8145 (49) | 2818 (56) | |
Female | 10,846 (50) | 8639 (51) | 2207 (44) | |
Primary site | 0.001 | |||
Main bronchus | 2534 (12) | 1910 (11) | 624 (12) | |
Upper lobe of lung | 10,852 (50) | 8442 (50) | 2410 (48) | |
Middle lobe of lung | 876 (4) | 703 (4) | 173 (3) | |
Lower lobe of lung | 4547 (21) | 3480 (21) | 1067 (21) | |
Overlapping lesion of lung | 334 (2) | 250 (1) | 84 (2) | |
Lung, NOS | 2666 (12) | 1999 (12) | 667 (13) | |
Laterality | < 0.001 | |||
Left | 8974 (41) | 6851 (41) | 2123 (42) | |
Right | 12,254 (56) | 9525 (57) | 2729 (54) | |
Bilateral, single primary | 189 (1) | 124 (1) | 65 (1) | |
Paired site | 309 (1) | 216 (1) | 93 (2) | |
Others | 83 | 68 | 15 | |
Histology type | < 0.001 | |||
SCLC | 20,539 (94) | 15,733 (94) | 4806 (96) | |
LCNEC | 1270 (6) | 1051 (6) | 219 (4) | |
T stage | < 0.001 | |||
T1 | 2760 (13) | 2325 (14) | 435 (9) | |
T2 | 5868 (27) | 4586 (27) | 1282 (26) | |
T3 | 4839 (22) | 3650 (22) | 1189 (24) | |
T4 | 8342 (38) | 6223 (37) | 2119 (42) | |
N stage | < 0.001 | |||
N0 | 3501 (16) | 3049 (18) | 452 (9) | |
N1 | 1628 (7) | 1330 (8) | 298 (6) | |
N2 | 11,900 (55) | 9095 (54) | 2805 (56) | |
N3 | 4780 (22) | 3310 (20) | 1470 (29) | |
Marital status | < 0.001 | |||
Married | 10,558 (48) | 7942 (47) | 2616 (52) | |
Others | 11,251 (52) | 8842 (53) | 2409 (48) | |
Brain metastasis | < 0.001 | |||
Yes | 3642 (17) | 2595 (15) | 1047 (21) | |
No | 18,167 (83) | 14,189 (85) | 3978 (79) | |
Liver metastasis | < 0.001 | |||
Yes | 6404 (29) | 3656 (22) | 2748 (55) | |
No | 15,405 (71) | 13,128 (78) | 2277 (45) | |
Lung metastasis | < 0.001 | |||
Yes | 3194 (15) | 2064 (12) | 1130 (22) | |
No | 18,615 (85) | 14,720 (88) | 3895 (78) |
