2. Results of trial group analyses for overall survival (Main group of 13 trials only).

	HR(95%CI)	Interaction p‐value
Planned Chemotherapy type Platinum based Non‐platinum based	0.84 (0.72‐0.98) 0.76 (0.62‐0.94)	0.48
Planned Radiotherapy dose > 45 Gy + BRT < 45 Gy + BRT	0.78 (0.68‐0.89) 0.93 (0.70‐1.24)	0.26
Planned Radiotherapy duration < 8 weeks > 8 weeks	0.83 (0.72‐0.96) 0.73 (0.57‐0.93)	0.35
Planned chemotherapy cycle length < 1 week > 1 week	0.74 (0.60‐0.92) 0.95 (0.72‐1.25)	0.16
Planned Cisplatin dose intensity < 25mg/m2/week > 25mg/m2/week	0.93 (0.70‐1.24) 0.76 (0.62‐0.96)	0.25
Cisplatin regimen Single‐agent Combination	0.76 (0.62‐0.93) 0.93 (0.70‐1.24)	0.25
Chemotherapy regimen Single agent Combination	0.75 (0.63‐0.88) 0.86 (0.71‐1.04)	0.29