Table 1.
Baseline characteristics of ES-SCLC patients before and after PSM
| Characteristic | Before matching | Characteristic | After matching | ||||
|---|---|---|---|---|---|---|---|
| TRT Group (n = 117) |
non-TRT Group (n = 159) |
P value | TRT Group (n = 99) |
non-TRT Group (n = 98) |
P value | ||
| Age, years | 0.363 | Age, years | 0.939 | ||||
| < 60 | 55(47.0%) | 66(41.5%) | < 60 | 46(46.5%) | 45(45.9%) | ||
| ≥60 | 62(53.0%) | 93(58.5%) | ≥60 | 53(53.5%) | 53(54.1%) | ||
| Gender | 0.135 | Gender | 0.492 | ||||
| Male | 92(78.6%) | 136(85.5%) | Male | 78(78.8%) | 81(82.7%) | ||
| Female | 25(21.4%) | 23(14.5%) | Female | 21(21.2%) | 17(17.3%) | ||
| Smoking history | 0.486 | Smoking history | 0.821 | ||||
| Yes | 65(55.6%) | 95(59.7%) | Yes | 56(56.6%) | 57(58.2%) | ||
| No | 52(44.4%) | 64(40.3%) | No | 43(43.4%) | 41(41.8%) | ||
| ECOG PS | 0.08 | ECOG PS | 0.418 | ||||
| 0–1 | 92(78.6%) | 110(69.2%) | 0–1 | 74(74.7%) | 78(79.6%) | ||
| 2 | 25(21.4%) | 49(30.8%) | 2 | 25(25.3%) | 20(20.4%) | ||
| T stage | 0.909 | T stage | 0.832 | ||||
| T1-T2 | 61(52.1%) | 84(52.8%) | T1-T2 | 48(48.5%) | 49(50.0%) | ||
| T3-T4 | 56(47.9%) | 75(47.2%) | T3-T4 | 51(51.5%) | 49(50.0%) | ||
| N stage | 0.387 | N stage | 0.434 | ||||
| N0-N2 | 61(52.1%) | 73(45.9%) | N0-N2 | 53(53.5%) | 47(48.0%) | ||
| N3 | 56(47.9%) | 86(54.1%) | N3 | 46(46.5%) | 51(52.0%) | ||
| M stage | 0.002 | M stage | 0.665 | ||||
| M1a | 24 (20.5%) | 21 (13.2%) | M1a | 19 (19.2%) | 17 (17.4%) | ||
| M1b | 72 (61.5%) | 80 (50.3%) | M1b | 60 (60.6%) | 56 (57.1%) | ||
| M1c | 21 (18.0%) | 58 (36.5%) | M1c | 20 (20.2%) | 25 (25.5%) | ||
| Type of ICIs | 0.652 | Type of ICIs | 0.793 | ||||
| PD-1 | 36(30.8%) | 53(33.3%) | PD-1 | 31(31.3%) | 29(29.6%) | ||
| PD-L1 | 81(69.2%) | 106(66.7%) | PD-L1 | 68(68.7%) | 69(70.4%) | ||
| NO. of metastatic sites | 0.004 | NO. of metastatic sites | 0.837 | ||||
| ≤ 2 | 106(90.6%) | 123(77.4%) | ≤ 2 | 88(88.9%) | 88(89.8%) | ||
| > 2 | 11(9.4%) | 36(22.6%) | > 2 | 11(11.1%) | 10(10.2%) | ||
| Brain metastases | 0.295 | Brain metastases | 0.725 | ||||
| Yes | 40(34.2%) | 45(28.3%) | Yes | 33(33.3%) | 35(35.7%) | ||
| No | 77(65.8%) | 114(71.7%) | No | 66(66.7%) | 63(64.3%) | ||
| Liver metastases | < 0.001 | Liver metastases | 0.899 | ||||
| Yes | 24(20.5%) | 66 (41.5%) | Yes | 24(24.2%) | 23(23.5%) | ||
| No | 93(79.5%) | 93(58.5%) | No | 75(75.8%) | 75(76.5%) | ||
| Bone metastases | 0.039 | Bone metastases | 0.596 | ||||
| Yes | 27(23.1%) | 55(34.6%) | Yes | 24(24.2%) | 27(27.6%) | ||
| No | 90(76.9%) | 104(65.4%) | No | 75(75.8%) | 71(72.4%) | ||
| Response evaluation* | 0.794 | Response evaluation* | 0.758 | ||||
| CR/PR | 81(69.2%) | 107(67.3%) | CR/PR | 67(67.7%) | 69(70.4%) | ||
| SD | 36(30.8%) | 52(32.7%) | SD | 32(32.3%) | 29(29.6%) | ||
PSM, propensity score matching; ECOG PS, Eastern Cooperative Oncology Group Performance Status; ICIs, immune checkpoint inhibitors; NO., number; TRT, thoracic radiotherapy
*Response evaluation before TRT or immunotherapy maintenance