Table 1 The clinicopathologic characteristics of patients in the training and validation cohorts
Variable | All cohort | Training cohort | Validation cohort | P value | ||
|---|---|---|---|---|---|---|
N = 153 (%) | N = 123 | % | N = 30 | % | ||
Sex | 0.248* | |||||
Male | 115 (75.2) | 90 | 73.2 | 25 | 83.3 | |
Female | 38 (24.8) | 33 | 26.8 | 5 | 16.7 | |
Age (year, mean ± SD) | 59.7 ± 8.9 | 59.5 ± 9.0 | 60.5 ± 8.8 | 0.583** | ||
Smoking status | 0.157* | |||||
No | 58 (37.9) | 50 | 40.7 | 8 | 26.7 | |
Yes | 95 (62.1) | 73 | 59.3 | 22 | 73.3 | |
Drinking status | 0.379* | |||||
No | 107 (69.9) | 88 | 71.5 | 19 | 63.3 | |
Yes | 46 (30.1) | 35 | 28.5 | 11 | 36.7 | |
Tumor length (cm, mean ± SD) | 3.6 ± 1.5 | 3.7 ± 1.7 | 3.3 ± 1.0 | 0.227** | ||
PD-L1 expression | 0.780* | |||||
Low | 80 (52.3) | 65 | 52.8 | 15 | 50.0 | |
High | 73 (47.7) | 58 | 47.2 | 15 | 50.0 | |
Surgery approach | 0.156* | |||||
Left thorax | 108 (70.6) | 90 | 73.2 | 18 | 60.0 | |
Right thorax | 45 (29.4) | 33 | 26.8 | 12 | 40.0 | |
Differentiation | 0.013* | |||||
Well-moderate | 71 (46.4) | 51 | 41.5 | 20 | 66.7 | |
Poor | 82 (53.6) | 72 | 58.5 | 10 | 33.3 | |
pT stage | 0.549* | |||||
T2 | 59 (38.6) | 46 | 37.4 | 13 | 43.3 | |
T3 | 94 (61.4) | 77 | 62.6 | 17 | 56.7 | |
NLNs (mean ± SD) | 19.7 ± 14.1 | 19.3 ± 13.9 | 21.4 ± 14.9 | 0.470** | ||
pTNM stage | 0.102* | |||||
IB | 52 (34.0) | 38 | 30.9 | 14 | 46.7 | |
IIA | 101 (66.0) | 85 | 69.1 | 16 | 53.3 | |
LNs dissection of left recurrent laryngeal nerve | 0.592* | |||||
No | 47 (30.7) | 39 | 31.7 | 8 | 26.7 | |
Yes | 106 (69.3) | 84 | 68.3 | 22 | 73.3 | |
LNs dissection of right recurrent laryngeal nerve | 0.415* | |||||
No | 45 (29.4) | 38 | 30.9 | 7 | 23.3 | |
Yes | 108 (70.6) | 85 | 69.1 | 23 | 76.7 | |
Dissection of left gastric artery LNs | 1.00*** | |||||
No | 9 (5.9) | 7 | 5.7 | 2 | 6.7 | |
Yes | 144 (94.1) | 116 | 94.3 | 28 | 93.3 | |
Dissection of subcarinal LNs | 0.69*** | |||||
No | 10 (6.5) | 9 | 7.3 | 1 | 3.3 | |
Yes | 143 (93.5) | 114 | 92.7 | 29 | 96.7 | |