5. Results of subgroup analyses (survival ‐ combination CT trials only).

Subgroup	Categories	Interaction	Trend
Age	≺55, 55 to ≺ 65, ≧ 65	1.572 (2 d.f.) P=0.456	0.482 (1 d.f.) P=0.488
Sex	Male, Female	0.266 (1d.f) P=0.606	‐
T category	T1‐2, T3, T4	0.324 (2 d.f.) P=0.850	0.108 (1 d.f.) P=0.742
N category	N0, N1/N2	0.080 (1d.f.) P=0.777	‐
Grade	G1/G2, G3/G4	1.154 (1d.f.) P=0.283	‐
Tumour diameter (cm)	≺ 2.5, 2.5 to 5.0, ≻ 5.0	7.733 (2 d.f.) P=0.021	7.079 (1d.f.) P=0.008
Performance status	0, 1, 2 to 3	1.511 (2 d.f.) P=0.470	0.004 (1 d.f.) P=0.95
Renal function (GFR)	≦ 59, 60 to 69, ≻ 69	3.573 (2 d.f.) P=0.168	3.564 (1d.f.) P=0.059
d.f. = degrees of freedom