Table 1. Baseline characteristics of the matched IMA and NMA patient cohorts.
| Variables | All (N=499) | Before PSM | After PSM | |||||
|---|---|---|---|---|---|---|---|---|
| IMA (N=97) | NMA (N=402) | P value | IMA (N=97) | NMA (N=97) | P value | |||
| Gender, n (%) | 0.026* | 0.886 | ||||||
| Female | 304 (60.9) | 49 (50.5) | 255 (63.4) | 49 (50.5) | 51 (52.6) | |||
| Male | 195 (39.1) | 48 (49.5) | 147 (36.6) | 48 (49.5) | 46 (47.4) | |||
| Age, n (%) | 0.563 | 1.000 | ||||||
| ≤60 years | 278 (55.7) | 51 (52.6) | 227 (56.5) | 51 (52.6) | 51 (52.6) | |||
| >60 years | 221 (44.3) | 46 (47.4) | 175 (43.5) | 46 (47.4) | 46 (47.4) | |||
| Smoke, n (%) | <0.001* | 0.072 | ||||||
| No | 363 (72.7) | 56 (57.7) | 307 (76.4) | 56 (57.7) | 69 (71.1) | |||
| Yes | 136 (27.3) | 41 (42.3) | 95 (23.6) | 41 (42.3) | 28 (28.9) | |||
| T, n (%) | 0.462 | 1.000 | ||||||
| T1/T2 | 473 (94.8) | 90 (92.8) | 383 (95.3) | 90 (92.8) | 91 (93.8) | |||
| T3/T4 | 26 (5.2) | 7 (7.2) | 19 (4.7) | 7 (7.2) | 6 (6.2) | |||
| N, n (%) | 0.070 | 0.506 | ||||||
| N0 | 305 (61.1) | 69 (71.1) | 236 (58.7) | 69 (71.1) | 66 (68.0) | |||
| N1 | 64 (12.8) | 8 (8.2) | 56 (13.9) | 8 (8.2) | 13 (13.4) | |||
| N2/N3 | 130 (26.1) | 20 (20.6) | 110 (27.4) | 20 (20.6) | 18 (18.6) | |||
| Stage, n (%) | 0.033 | 0.461 | ||||||
| I | 289 (57.9) | 66 (68.0) | 223 (55.5) | 66 (68.0) | 64 (66.0) | |||
| II | 72 (14.4) | 7 (7.2) | 65 (16.2) | 7 (7.2) | 12 (12.4) | |||
| III | 138 (27.7) | 24 (24.7) | 114 (28.4) | 24 (24.7) | 21 (21.6) | |||
| Lymphovascular invasion, n (%) | 0.131 | 0.668 | ||||||
| No | 414 (83.0) | 86 (88.7) | 328 (81.6) | 86 (88.7) | 83 (85.6) | |||
| Yes | 85 (17.0) | 11 (11.3) | 74 (18.4) | 11 (11.3) | 14 (14.4) | |||
| Perineural invasion, n (%) | 1.000 | 0.745 | ||||||
| No | 467 (93.6) | 91 (93.8) | 376 (93.5) | 91 (93.8) | 93 (95.9) | |||
| Yes | 32 (6.4) | 6 (6.2) | 26 (6.5) | 6 (6.2) | 4 (4.1) | |||
| Pleural involvement, n (%) | 1.000 | 1.000 | ||||||
| No | 300 (60.1) | 58 (59.8) | 242 (60.2) | 58 (59.8) | 58 (59.8) | |||
| Yes | 199 (39.9) | 39 (40.2) | 160 (39.8) | 39 (40.2) | 39 (40.2) | |||
| Laterality, n (%) | 0.180 | 0.286 | ||||||
| Left | 203 (40.7) | 44 (45.4) | 159 (39.6) | 44 (45.4) | 52 (53.6) | |||
| Right | 285 (57.1) | 53 (54.6) | 232 (57.7) | 53 (54.6) | 44 (45.4) | |||
| Bilateral | 11 (2.2) | 0 (0.0) | 11 (2.7) | 0 (0.0) | 1 (1.0) | |||
| Location, n (%) | 0.007* | 0.607 | ||||||
| Upper | 270 (54.2) | 40 (41.2) | 230 (57.4) | 40 (41.2) | 43 (44.3) | |||
| Middle | 40 (8.0) | 13 (13.4) | 27 (6.7) | 13 (13.4) | 9 (9.3) | |||
| Lower | 182 (36.5) | 44 (45.4) | 138 (34.4) | 44 (45.4) | 44 (45.4) | |||
| Other | 6 (1.2) | 0 (0.0) | 6 (1.5) | 0 (0.0) | 1 (1.0) | |||
| Operation, n (%) | 0.134 | 0.592 | ||||||
| Sublobar resection | 36 (7.2) | 4 (4.1) | 32 (8.0) | 4 (4.1) | 2 (2.1) | |||
| Lobectomy | 459 (92.0) | 91 (93.8) | 368 (91.5) | 91 (93.8) | 94 (96.9) | |||
| Pneumonectomy | 4 (0.8) | 2 (2.1) | 2 (0.5) | 2 (2.1) | 1 (1.0) | |||
*, P value is less than 0.05. PSM, propensity score matching; IMA, pulmonary invasive mucinous adenocarcinoma group; NMA, pulmonary non-invasive mucinous adenocarcinoma group.