Table 1. Baseline characteristics of cohorts before and after propensity score matching to examine the difference with or without ACRT after receiving NCRT and surgery.
| Variables | Before PSM | After PSM | ||||
|---|---|---|---|---|---|---|
| no-ACRT | ACRT | p | no-ACRT | ACRT | p | |
| n | 4968 | 837 | 830 | 830 | ||
| Age | 0.010 | 0.428 | ||||
| ≤ 65 | 2632 (53.0) | 484 (57.8) | 465 (56.0) | 482 (58.1) | ||
| > 65 | 2336 (47.0) | 353 (42.2) | 365 (44.0) | 348 (41.9) | ||
| Year of diagnosis | <0.001 | 0.920 | ||||
| 2007–2011 | 1415 (28.5) | 221 (26.4) | 213 (25.7) | 220 (26.5) | ||
| 2012–2016 | 1937 (39.0) | 263 (31.4) | 263 (31.7) | 262 (31.6) | ||
| 2017–2020 | 1616 (32.5) | 353 (42.2) | 354 (42.7) | 348 (41.9) | ||
| Gender | 0.016 | 0.380 | ||||
| Male | 4116 (82.9) | 722 (86.3) | 729 (87.8) | 716 (86.3) | ||
| Female | 852 (17.1) | 115 (13.7) | 101 (12.2) | 114 (13.7) | ||
| Marital | 0.101 | 0.591 | ||||
| Other | 977 (19.7) | 139 (16.6) | 134 (16.1) | 138 (16.6) | ||
| Married | 3325 (66.9) | 576 (68.8) | 589 (71.0) | 572 (68.9) | ||
| Single | 666 (13.4) | 122 (14.6) | 107 (12.9) | 120 (14.5) | ||
| Race | 0.126 | 0.111 | ||||
| Other | 244 (4.9) | 51 (6.1) | 32 (3.9) | 50 (6.0) | ||
| White | 4494 (90.5) | 757 (90.4) | 772 (93.0) | 751 (90.5) | ||
| Black | 230 (4.6) | 29 (3.5) | 26 (3.1) | 29 (3.5) | ||
| T classification | 0.346 | 0.648 | ||||
| T1 | 604 (12.2) | 103 (12.3) | 101 (12.2) | 99 (11.9) | ||
| T2 | 894 (18.0) | 133 (15.9) | 127 (15.3) | 133 (16.0) | ||
| T3 | 3255 (65.5) | 557 (66.5) | 569 (68.6) | 555 (66.9) | ||
| T4 | 215 (4.3) | 44 (5.3) | 33 (4.0) | 43 (5.2) | ||
| N classification | <0.001 | 0.968 | ||||
| N0 | 1800 (36.2) | 220 (26.3) | 219 (26.4) | 219 (26.4) | ||
| N1 | 2876 (57.9) | 521 (62.2) | 515 (62.0) | 521 (62.8) | ||
| N2 | 256 (5.2) | 85 (10.2) | 85 (10.2) | 79 (9.5) | ||
| N3 | 36 (0.7) | 11 (1.3) | 11 (1.3) | 11 (1.3) | ||
| TNM stage | <0.001 | 0.965 | ||||
| I | 395 (8.0) | 56 (6.7) | 58 (7.0) | 56 (6.7) | ||
| II | 1932 (38.9) | 246 (29.4) | 241 (29.0) | 245 (29.5) | ||
| III | 2641 (53.2) | 535 (63.9) | 531 (64.0) | 529 (63.7) | ||
| Histological grade | 0.120 | 0.743 | ||||
| Well | 221 (4.4) | 37 (4.4) | 31 (3.7) | 37 (4.5) | ||
| Moderately | 1927 (38.8) | 310 (37.0) | 299 (36.0) | 307 (37.0) | ||
| Poorly | 2140 (43.1) | 394 (47.1) | 393 (47.3) | 390 (47.0) | ||
| Unknown | 680 (13.7) | 96 (11.5) | 107 (12.9) | 96 (11.6) | ||
| Tumor histology | 0.061 | 0.530 | ||||
| ADC | 3599 (72.4) | 633 (75.6) | 645 (77.7) | 627 (75.5) | ||
| SCC | 916 (18.4) | 126 (15.1) | 110 (13.3) | 125 (15.1) | ||
| Other | 453 (9.1) | 78 (9.3) | 75 (9.0) | 78 (9.4) | ||
Data were presented as n (%). PSM, propensity score matching; ACRT, adjuvant radiotherapy or adjuvant chemotherapy; ADC, adenocarcinoma; SCC, squamous cell carcinoma.