Table 3.

Association between clinical characteristics and post-progression survival among 288 patients with advanced stage lung adenocarcinoma and available data of CEA^In and CEA^Pd, stratified by EGFR mutation status.

Predictor	EGFR wild-type (n = 94)		EGFR mutant (n = 194)
	aHR (95% CI)	P value	aHR (95% CI)	P value
Age ≥ 65 years	1.82 (1.04–3.19)	0.036	0.82 (0.57–1.18)	0.277
Male sex	1.73 (0.95–3.15)	0.072	1.32 (0.83–2.11)	0.241
Stage IV	2.39 (1.19–4.81)	0.015	3.43 (1.63–7.22)	0.001*
Ever smoking	1.17 (0.63–2.16)	0.624	0.68 (0.41–1.14)	0.142
CEAIn
<5 ng/mL	Reference		Reference
5–100 ng/mL	1.50 (0.70–3.23)	0.300	0.61 (0.36–1.01)	0.057
>100 ng/mL	1.13 (0.39–3.25)	0.823	0.43 (0.22–0.85)	0.014
CEAPd
<5 ng/mL	Reference		Reference
5–100 ng/mL	1.28 (0.59–2.79)	0.531	2.55 (1.48–4.42)	0.001*
>100 ng/mL	1.94 (0.75–5.03)	0.175	4.39 (2.22–8.70)	<0.001*

HR, hazard ratio; aHR, adjusted hazard ratio; CI, confidence interval; EGFR, epidermal growth factor receptor; CEA^In, serum carcinoembryonic antigen level at initial diagnosis; CEA^Pd, serum carcinoembryonic antigen level at disease progression;

^*Statistically significant after a Bonferroni adjustment at P < 0.0071.