Table 1.
Demographic and clinical characteristics of the patients
| Characteristic | Training cohort | Validation cohort | p-value |
|---|---|---|---|
| (n = 64) | (n = 28) | ||
| Sex, n. (%) | 0.086 | ||
| Female | 14 (21.88) | 11 (39.29) | |
| Male | 50 (78.12) | 17(60.71) | |
| Age(years), mean (SD) | 20.44 (8.98) | 20.04 (8.99) | 0.844 |
| Smoking status, n. (%) | 0.656 | ||
| No | 34 (53.10) | 17 (60.7) | |
| Yes | 30 (46.90) | 11 (39.3) | |
| Family history, n. (%) | 0.754 | ||
| No | 62 (96.90) | 26 (92.9) | |
| Yes | 2 (3.10) | 2 (7.1) | |
| TTF-1, n. (%) | 0.070 | ||
| Negative | 42 (65.60) | 12 (42.9) | |
| Positive | 22 (34.40) | 16 (57.1) | |
| Ki-67, n. (%) | 0.560 | ||
| Low expression | 33 (51.60) | 17 (60.7) | |
| High expression | 31 (48.40) | 11 (39.3) | |
| Histologic type, n. (%) | 0.120 | ||
| Adenocarcinoma | 32 (50.00) | 20 (71.43) | |
| Squamous cell carcinoma | 28 (43.80) | 6 (21.43) | |
| NOS | 4 (6.20) | 2 (7.14) | |
| Stage, n. (%) | 0.257 | ||
| Ш | 23 (35.90) | 6 (21.40) | |
| IV | 41 (64.10) | 22 (78.60) | |
| T stage, n. (%) | 0.842 | ||
| 0 | 1 ( 1.60) | 0 ( 0.00) | |
| 1 | 8 (12.50) | 3 (10.70) | |
| 2 | 20 (31.20) | 11 (39.30) | |
| 3 | 9 (14.10) | 5 (17.90) | |
| 4 | 26 (40.60) | 9 (32.10) | |
| N stage, n. (%) | 0.821 | ||
| 0 | 6 (9.38) | 3 (10.70) | |
| 1 | 5 (7.81) | 1 (3.60) | |
| 2 | 25 (39.06) | 13 (46.40) | |
| 3 | 28 (43.75) | 11 (39.30) | |
| M stage, n. (%) | 0.176 | ||
| 0 | 22 (34.40) | 5 (17.90) | |
| 1 | 42 (65.60) | 23 (82.10) | |
| Lymph node metastasis, n. (%) | 0.880 | ||
| No | 9 (14.10) | 5 (17.90) | |
| Yes | 55 (85.90) | 23 (82.10) | |
| Intrapulmonary metastasis, n. (%) | 0.466 | ||
| No | 39 (60.90) | 20 (71.40) | |
| Yes | 25 (39.10) | 8 (28.60) | |
| Brain metastasis, n. (%) | 0.330 | ||
| No | 55 (85.90) | 21 (75.00) | |
| Yes | 9 (14.10) | 7 (25.00) | |
| Liver metastasis, n. (%) | 1.000 | ||
| No | 59 (92.20) | 026 (92.90) | |
| Yes | 5 ( 7.80) | 2 (7.10) | |
| Bone metastasis n. (%) | 1.000 | ||
| No | 44 (68.80) | 019 (67.90) | |
| Yes | 20 (31.20) | 9 (32.10) | |
| Pleural metastasis n. (%) | 0.073 | ||
| No | 54 (84.38) | 19 (67.86) | |
| Yes | 10 (15.62) | 9 (32.14) | |
| White blood cell, (median [IQR]) | 6.40 [4.47, 7.78] | 6.15 [5.00, 8.33] | 0.333 |
| Neutrophil, (median [IQR]) | 69.05 [62.65,73.78] | 65.20 [58.50, 71.08] | 0.203 |
| Monocyte, (median [IQR]) | 8.65 [6.83, 11.03] | 6.70 [5.27, 9.45] | 0.952 |
| CRP, (median [IQR]) | 18.10 [5.05, 19.85] | 12.00 [1.17, 18.83] | 0.330 |
| CEA, (median [IQR]) | 13.60 [3.88, 84.30] | 11.30 [2.80, 84.30] | 0.568 |
| NSE, (median [IQR]) | 14.25 [10.35, 19.10] | 15.05 [12.00, 19.10] | 0.513 |
| PD-L1 expression, n. (%) | 0.9276 | ||
| < 1% | 30 (46.88) | 12 (42.86) | |
| ≥ 1% | 12 (18.75) | 6 (21.43) | |
| Unknown | 22 (34.37) | 10 (35.71) | |
| Therapy line, n. (%) | 0.7251 | ||
| 1st | 23 (35.94) | 9 (32.14) | |
| ≥ 2nd | 41 (64.06) | 19 (67.86) | |
| Immunotherapy regimen, n. (%) | 0.9366 | ||
| PD-1 inhibitors | 36 (56.25) | 16 (57.14) | |
| PD-1 inhibitors + chemotherapy | 28 (43.75) | 12 (42.86) |
CRP C-reactive protein, CEA carcinoembryonic antigen, NSE neuron-specific enolase, NOS not otherwise specified, four are adenosquamous carcinoma and two are small cell lung cancer