Table 5.

The multinomial logistic regression analysis to investigate the association between the expression of PD-L1 and EGFR mutations.

EGFR mutation	PD-L1 expression
	1–49% versus < 1%		≥ 50% versus < 1%
	Unadjusted OR (95% CI), P	Adjusted ORa (95% CI), P	Unadjusted OR (95% CI), P	Adjusted ORa (95% CI), P
Wild-type	Reference	Reference	Reference	Reference
Ex21	0.61 (0.30–1.22), 0.16	0.87 (0.41–1.85), 0.72	0.04 (0.01–0.31), < 0.001	0.10 (0.01–0.87), 0.03
Ex19	0.39 (0.17–0.88), 0.02	0.54 (0.23–1.30), 0.17	0.09 (0.02–0.46), < 0.001	0.23 (0.04–1.22), 0.08
Minor mutationb	0.83 (0.29–2.36), 0.72	1.05 (0.35–3.22), 0.93	0.25 (0.04–1.30), 0.09	0.38 (0.06–2.50), 0.31

PD-L1 programmed death-ligand 1, EGFR epidermal growth factor receptor gene, OR odds ratio, CI confidence interval, Ex21 exon 21 L858R mutation, Ex19 exon19 deletion mutation.

^aAdjusted by age, sex, smoking status, pathological stage and histological type.

^bDefined as all mutations except Ex21 and Ex19.