Table 3.

Multivariate analyses of factors that might affect the presence of EGFR, HER2 or KRAS mutations

EGFR mutation
Variable	Category	OR	95% CI	P
Age	≥58 years/<58 years	1.93	1.15–3.24	0.013
Stage	I+II/III+IV	1.46	0.84–2.54	0.180
Differentiation	Poor/Moderate+Well	0.64	0.35–1.16	0.144
Histological subtype	Acinar predominant/Othersa	2.10	1.25–3.52	0.005
HER2 mutation
Variable	Category	OR	95% CI	P
Age	<58 years/≥58 years	4.17	1.15–15.11	0.030
Stage	I+II/III+IV	0.72	0.24–2.15	0.551
Differentiation	Poor/Moderate+Well	1.65	0.50–5.42	0.408
Histological subtype	IMA/Othersb	5.81	1.37–24.72	0.017
KRAS mutation
Variable	Category	OR	95% CI	P
Age	<58 years/≥58 years	2.32	0.42–12.98	0.337
Stage	I+II/III+IV	1.16	0.22–6.10	0.858
Differentiation	Poor/Moderate+Well	6.91	1.24–38.60	0.028
Histological subtype	IMA/Othersb	14.30	2.15–95.10	0.006

^aOthers, subtypes other than acinar predominant.

^bOthers, subtypes other than invasive mucinous adenocarcinoma.