Table 2.

Baseline characteristics of the non-response and response patients

	Non-response	Response	P value
Total (n)	112	138	–
Age (n)	64.2 ± 6.2	64.7 ± 5.5	0.472
Gender (n)
Female	23	30	0.817
Male	89	108
Smoking history (n)
Non-smoker	42	65	0.127
Smoker	70	73
Performance status
0–1	93	125	0.076
2	19	13
Tumor grade (n)
High-middle	91	102	0.169
Low	21	36
Tumor stage (n)
LDa	68	75	0.312
EDa	44	63
EGFR (n)a
Negative	83	119	0.016
Positive	29	19
KRAS (n)a
Negative	101	133	0.046
Positive	11	5
Serum PD-L1 (ng/ml)a	7.6 ± 2.5	6.6 ± 3.2	0.008

^aLD Limited disease, ED Extensive disease, EGFR Epidermal growth factor receptor, KRAS Kirsten rat sarcoma viral oncogene, PD-L1 Programmed death ligand 1