Table 1 The descriptive characteristics of NSCLC patients with PL before and after PSM

Year at diagnosis

 2010–2012

1273 (46.9%)

1029 (46.1%)

244 (50.1%)

418 (48.8%)

210 (49.1%)

208 (48.6%)

 2013–2015

1444 (53.1%)

1201 (53.9%)

243 (49.9%)

438 (51.2%)

218 (50.9%)

220 (51.4%)

Age

69.0 (14.1)

68.0 (13.8)

72.0 (15.6)

71.0 (13.3)

71.0 (16.6)

71.0 (16.1)

Gender

 Female

1380 (50.8%)

1126 (50.5%)

254 (52.2%)

446 (52.1%)

219 (51.2%)

227 (53.0%)

 Male

1337 (49.2%)

1104 (49.5%)

233 (47.8%)

410 (47.9%)

209 (48.8%)

201 (47.0%)

Race

 White

2185 (80.4%)

1792 (80.4%)

393 (80.7%)

712 (83.2%)

363 (84.8%)

349 (81.5%)

 Non-White

532 (19.6%)

438 (19.6%)

94 (19.3%)

144 (16.8%)

65 (15.2%)

79 (18.5%)

Marital status

 Married

1598 (58.8%)

1339 (60.0%)

259 (53.2%)

473 (55.3%)

244 (57.0%)

229 (53.5%)

 Unmarried

1119 (41.2%)

891 (40.0%)

228 (46.8%)

383 (44.7%)

184 (43.0%)

199 (46.5%)

Grade

 I

218 (8.0%)

176 (7.9%)

42 (8.6%)

65 (7.6%)

29 (6.8%)

36 (8.4%)

 II

1349 (49.7%)

1114 (50.0%)

235 (48.3%)

424 (49.5%)

213 (49.8%)

211 (49.3%)

 III

1112 (40.9%)

910 (40.8%)

202 (41.5%)

357 (41.7%)

181 (42.3%)

176 (41.1%)

 IV

38 (1.4%)

30 (1.3%)

8 (1.6%)

10 (1.2%)

5 (1.2%)

5 (1.2%)

T stage

 T2

1702 (62.6%)

1386 (62.2%)

316 (64.9%)

588 (68.7%)

289 (67.5%)

299 (69.9%)

 T3

847 (31.2%)

742 (33.3%)

105 (21.6%)

196 (22.9%)

103 (24.1%)

93 (21.7%)

 T4

168 (6.2%)

102 (4.6%)

66 (13.6%)

72 (8.4%)

36 (8.4%)

36 (8.4%)

N stage

 N0

1883 (69.3%)

1486 (66.6%)

397 (81.5%)

691 (80.7%)

340 (79.4%)

351 (82.0%)

 N1

387 (14.2%)

367 (16.5%)

20 (4.1%)

48 (5.6%)

29 (6.8%)

19 (4.4%)

 N2

433 (15.9%)

370 (16.6%)

63 (12.9%)

110 (12.9%)

55 (12.9%)

55 (12.9%)

 N3

14 (0.5%)

7 (0.3%)

7 (1.4%)

7 (0.8%)

4 (0.9%)

3 (0.7%)

Metastasis

 M0

2547 (93.7%)

2139 (95.9%)

408 (83.8%)

765 (89.4%)

381 (89.0%)

384 (89.7%)

 M1

170 (6.3%)

91 (4.1%)

79 (16.2%)

91 (10.6%)

47 (11.0%)

44 (10.3%)

Pathology

 Adenocarcinoma

1978 (72.8%)

1625 (72.9%)

353 (72.5%)

618 (72.2%)

308 (72.0%)

310 (72.4%)

 Others

67 (2.5%)

56 (2.5%)

11 (2.3%)

16 (1.9%)

7 (1.6%)

9 (2.1%)

 Squamous cell carcinoma

672 (24.7%)

549 (24.6%)

123 (25.3%)

222 (25.9%)

113 (26.4%)

109 (25.5%)

Pleural invasion

 PL-1

1280 (47.1%)

1073 (48.1%)

207 (42.5%)

389 (45.4%)

201 (47.0%)

188 (43.9%)

 PL-2

1076 (39.6%)

869 (39.0%)

207 (42.5%)

347 (40.5%)

170 (39.7%)

177 (41.4%)

 PL-3

361 (13.3%)

288 (12.9%)

73 (15.0%)

120 (14.0%)

57 (13.3%)

63 (14.7%)

Primary site

 Lower lobe

802 (29.5%)

667 (29.9%)

135 (27.7%)

243 (28.4%)

125 (29.2%)

118 (27.6%)

 Others

219 (8.1%)

177 (7.9%)

42 (8.6%)

73 (8.5%)

37 (8.6%)

36 (8.4%)

 Upper lobe

1696 (62.4%)

1386 (62.2%)

310 (63.7%)

540 (63.1%)

266 (62.1%)

274 (64.0%)

Laterality

 Left

1108 (40.8%)

868 (38.9%)

240 (49.3%)

406 (47.4%)

207 (48.4%)

199 (46.5%)

 Right

1609 (59.2%)

1362 (61.1%)

247 (50.7%)

450 (52.6%)

221 (51.6%)

229 (53.5%)

Tumor size

3.0 (1.0)

3.2 (1.1)

2.2 (0.7)

2.4 (0.9)

2.5 (0.8)

2.3 (1.1)

Radiation

 None

2231 (82.1%)

1854 (83.1%)

377 (77.4%)

676 (79.0%)

335 (78.3%)

341 (79.7%)

 Radiotherapy

486 (17.9%)

376 (16.9%)

110 (22.6%)

180 (21.0%)

93 (21.7%)

87 (20.3%)

Chemotherapy

 None

1660 (61.1%)

1328 (59.6%)

332 (68.2%)

596 (69.6%)

293 (68.5%)

303 (70.8%)

 Chemotherapy

1057 (38.9%)

902 (40.4%)

155 (31.8%)

260 (30.4%)

135 (31.5%)

125 (29.2%)