Table 2.

EGFR mutation, ALK and PD-L1 expression in NSCLC according to the patients’ smoking status (N = 191)

Characteristic	No. of patients (%) (Total = 191)			P value
Smoking status	Total	Ever smoker	Never smoker
		n = 90 (47.1%)	n = 101 (52.9%)
Gender
Male	115 (60.2%)	85 (73.9%)	30 (26.1%)	< 0.0001
Female	76 (39.8%)	5 (6.6%)	71 (93.4%)
EGFR mutation
Positive	81 (42.4%)	16 (17.8%)	65 (64.4%)	< 0.0001
Negative	110 (57.6%)	74 (82.2%)	36 (35.6%)
ALK
Positive	8 (4.2%)	2 (2.2%)	6 (5.9%)	0.285
Negative	183 (95.8%)	88 (97.8%)	95 (94.1%)
PD-L1 expression
TPS ≥ 50% (High expression)	38 (19.9%)	24 (26.7%)	14 (13.9%)	0.042*
TPS 1% to 49% (Low expression)	81 (42.4%)	35 (38.9%)	46 (45.5%)
TPS < 1% (No expression)	72 (37.7%)	31 (34.4%)	41 (40.6%)

TPS = Tumor proportion score

^*Comparison between high PD-L1 expression (TPS ≥ 50%) versus no (TPS < 1%) and low PD-L1 expression (TPS 1%-49%) in ever smoker versus never smoker