|
Characteristic
|
Development cohort (n = 117)
|
Validation cohort (n = 144)
|
p-value†
|
|---|
|
n (%)
|
n (%)
|
|---|
|
Sex
| | |
0.1
|
|
Male
|
79 (67.5)
|
83 (57.6)
| |
|
Female
|
38 (32.5)
|
61 (42.4)
| |
|
Age (years)
| | |
0.31
|
|
Median (range)
|
73 (34–90)
|
74 (45–91)
| |
|
ECOG performance status
| | |
0.025
|
|
0
|
55 (47.0)
|
44 (30.6)
| |
|
1
|
35 (29.9)
|
61 (42.4)
| |
|
≥ 2
|
27 (23.1)
|
36 (25.0)
| |
|
Unknown
|
0 (0)
|
3 (2.1)
| |
|
SCS
| | |
0.16
|
|
0–9
|
77 (65.8)
|
104 (72.2)
| |
|
10–20
|
40 (34.2)
|
37 (35.6)
| |
|
Unknown
|
0 (0)
|
3 (2.1)
| |
|
Smoking status
| | |
0.53
|
|
Current
|
38 (32.5)
|
37 (25.7)
| |
|
Past
|
71 (60.7)
|
93 (64.6)
| |
|
Never
|
7 (6.0)
|
10 (6.9)
| |
|
Unknown
|
1 (0.9)
|
4 (2.8)
| |
|
Pack years smoked
| | |
0.7
|
|
Median (range)
|
40 (0–150)
|
40 (0–150)
| |
|
Unknown
|
7 (6.0)
|
7 (4.9)
| |
|
Weight loss (%)
| | |
< 0.001
|
|
None
|
57 (48.7)
|
41 (28.5)
| |
|
≤ 10
|
29 (24.8)
|
51 (35.4)
| |
|
> 10
|
25 (21.4)
|
7 (4.9)
| |
|
Unknown
|
6 (5.1)
|
45 (31.3)
| |
|
FEV1 (%)
| | |
0.19
|
|
Median (range)
|
68 (25–121)
|
68 (30–133)
| |
|
Unknown
|
16 (13.7)
|
36 (25.0)
| |
|
DLCO (%)
| | |
0.5
|
|
Median (range)
|
60 (28–115)
|
58 (28–134)
| |
|
Unknown
|
24 (20.5)
|
84 (58.3)
| |
|
Overall stage
| | |
0.016
|
|
I
|
34 (29.1)
|
62 (43.1)
| |
|
II
|
22 (18.8)
|
13 (9.0)
| |
|
III
|
61 (52.1)
|
69 (47.9)
| |
|
T stage
| | |
0.086
|
|
T1
|
31 (26.5)
|
54 (37.5)
| |
|
T2
|
38 (32.5)
|
52 (36.1)
| |
|
T3
|
33 (28.2)
|
25 (17.4)
| |
|
T4
|
14 (12.0)
|
13 (9.0)
| |
|
Unknown
|
1 (0.9)
|
0 (0)
| |
|
N stage
| | |
0.065
|
|
N0
|
56 (47.9)
|
79 (54.9)
| |
|
N1
|
14 (12.0)
|
5 (3.5)
| |
|
N2
|
31 (26.5)
|
42 (29.2)
| |
|
N3
|
16 (13.7)
|
18 (12.5)
| |
|
Histological diagnosis
| | |
0.034
|
|
Squamous cell carcinoma
|
64 (54.7)
|
24 (16.7)
| |
|
Adenocarcinoma
|
37 (31.6)
|
45 (31.3)
| |
|
Other
|
16 (13.7)
|
69 (47.9)
| |
|
Tumour grade
| | |
0.11
|
|
< 3
|
36 (30.8)
|
24 (16.7)
| |
|
3
|
39 (33.3)
|
45 (31.3)
| |
|
Unknown
|
42 (35.9)
|
75 (52.1)
| |
|
Tumour laterality
| | |
0.23
|
|
Left
|
48 (41.0)
|
71 (49.3)
| |
|
Right
|
67 (57.3)
|
73 (50.7)
| |
|
Unknown
|
2 (1.7)
|
0 (0)
| |
|
Tumour lobe
| | |
0.76
|
|
Upper
|
71 (60.7)
|
86 (59.7)
| |
|
Middle/lower
|
44 (37.6)
|
57 (39.6)
| |
|
Unknown
|
2 (1.7)
|
1 (0.7)
| |
|
GTV (cc)
| | |
0.32
|
|
Median (range)
|
49.8 (0.7–1039.0)
|
23 (1.7–1065.0)
| |
|
Unknown
|
26 (22.2)
|
29 (20.1)
| |
|
Mutation status
| | |
0.28
|
|
EGFR positive
|
4 (3.4)
|
8 (5.6)
| |
|
ALK positive
|
1 (0.9)
|
2 (1.4)
| |
|
None
|
36 (30.8)
|
30 (20.8)
| |
|
Unknown
|
76 (65.0)
|
104 (72.2)
| |
|
PD-L1 status (%)
| | |
0.45
|
|
< 1
|
4 (3.4)
|
2 (1.4)
| |
|
1–49
|
8 (6.8)
|
4 (2.8)
| |
|
≥ 50
|
5 (4.3)
|
2 (1.4)
| |
|
Unknown
|
100 (85.5)
|
136 (94.4)
| |
|
Radiotherapy technique
| | |
< 0.001
|
|
Conformal
|
15 (12.8)
|
80 (55.6)
| |
|
IMRT
|
80 (68.4)
|
24 (16.7)
| |
|
VMAT
|
22 (18.8)
|
39 (27.1)
| |
|
Unknown
|
0 (0)
|
1 (0.7)
| |
|
Radiotherapy treatment duration (days)
| | |
0.37
|
|
Median (range)
|
26 (1–47)
|
22 (1–48)
| |
|
EQD2 (Gy)
| | |
0.12
|
|
Median (range)
|
60 (12–126)
|
60 (6.3–88)
| |
|
Chemotherapy use
| | |
0.18
|
|
Chemotherapy
|
45 (38.5)
|
44 (30.6)
| |
|
No chemotherapy
|
72 (61.5)
|
100 (69.4)
| |
|
Survival time (months)
| | |
0.011
|
|
Median (range)
|
17 (1–44)
|
22 (0–46)
| |
|
2-year status
| | |
0.92
|
|
Alive
|
56 (47.9)
|
68 (47.2)
| |
|
Dead
|
61 (52.1)
|
76 (52.8)
| |
- ECOG = Eastern Cooperative Oncology Group; SCS = Simplified Comorbidity Score; FEV1 = forced expiratory volume in 1 s; DLCO = diffusing capacity of the lung for carbon monoxide; GTV = gross tumour volume; EGFR = epidermal growth factor receptor; ALK = anaplastic lymphoma kinase, PD-L1 = programmed death-ligand 1; IMRT = intensity-modulated radiotherapy; VMAT = volumetric modulated arc therapy; EQD2 = equivalent dose in 2 Gy fractions
- †Comparison of development and validation cohort
