Table 1. Demographics and clinical characteristics of patients selected.
| Factors | No SPC (%) | SPC (%) | P value |
|---|---|---|---|
| Total | 226,374 (93.6) | 15,431 (6.4) | |
| Gender | 0.009 | ||
| Female | 104,358 (93.5) | 7,281 (6.5) | |
| Male | 122,016 (93.7) | 8,150 (6.3) | |
| Race | 0.000 | ||
| White | 180,806 (93.3) | 13,054 (6.7) | |
| Black | 27,420 (94.6) | 1,554 (5.4) | |
| Others | 18,148 (95.7) | 823 (4.3) | |
| Age | 0.000 | ||
| ≤60 | 57,272 (95.0) | 3,029 (5.0) | |
| 61–70 | 70,855 (92.6) | 5,689 (7.4) | |
| 71–80 | 67,280 (92.8) | 5,239 (7.2) | |
| >80 | 30,967 (95.5) | 1,474 (4.5) | |
| Differentiation | 0.000 | ||
| Well | 13,196 (88.6) | 1,699 (11.4) | |
| Moderate | 48,311 (90.5) | 5,076 (9.5) | |
| Poor | 64,400 (93.3) | 4,654 (6.7) | |
| Undifferentiated | 3,622 (93.6) | 247 (6.4) | |
| Unknown | 96,845 (96.3) | 3,755 (3.7) | |
| Histology | 0.000 | ||
| Squamous | 71,872 (93.8) | 5,214 (6.2) | |
| Adenocarcinoma | 139,336 (93.8) | 9,220 (6.2) | |
| Others | 15,166 (93.8) | 997 (6.2) | |
| T-stage | 0.000 | ||
| T0 | 967 (96.4) | 36 (3.6) | |
| T1 | 41,558 (87.9) | 5,741 (12.1) | |
| T2 | 65,352 (92.1) | 5,617 (7.9) | |
| T3 | 13,844 (95.0) | 731 (5.0) | |
| T4 | 82,018 (97.0) | 2,555 (3.0) | |
| Tx | 22,635 (96.8) | 751 (3.2) | |
| N-stage | 0.000 | ||
| N0 | 87,474 (89.7) | 10,087 (10.3) | |
| N1 | 19,684 (93.2) | 1,425 (6.8) | |
| N2 | 76,322 (96.5) | 2,739 (3.5) | |
| N3 | 25,935 (97.4) | 696 (2.6) | |
| Nx | 16,959 (97.2) | 484 (2.8) | |
| M-stage | 0.000 | ||
| M0 | 118,470 (90.4) | 12,532 (9.6) | |
| M1 | 99,611 (97.5) | 2,558 (2.5) | |
| Mx | 8,293 (96.1) | 341 (3.9) | |
| Marriage | 0.000 | ||
| Married | 116,431 (93.1) | 8,681 (6.9) | |
| Others | 109,943 (94.2) | 6,750 (5.8) | |
| Radiation | 0.000 | ||
| Radiation | 88,876 (95.3) | 4,377 (4.7) | |
| Others | 137,498 (92.6) | 11,054 (7.6) | |
| Chemotherapy | 0.000 | ||
| Yes | 100,570 (94.8) | 5,569 (5.2) | |
| Others | 125,804 (92.7) | 9,862 (7.3) | |
| Surgical procedure | 0.000 | ||
| No | 166,989 (96.6) | 5,894 (3.4) | |
| Sublobectomy | 11,430 (86.2) | 1,827 (13.8) | |
| Lobectomy | 42,853 (85.5) | 7,272 (14.5) | |
| Pneumonectomy | 3,393 (90.5) | 356 (9.5) | |
| Surgery (the type of operation is unclear.) | 537 (91.8) | 48 (8.2) | |
| Unknown | 1,172 (97.2) | 34 (2.8) | |
| Survival | 0.000 | ||
| Alive | 56,200 (89.9) | 6,301 (10.1) | |
| Dead | 170,174 (94.9) | 9,130 (5.1) |
NSCLC, non-small cell lung cancer; SPC, second primary cancer.