Table 1.

Correlations between expression levels of serum exo-eIF4E and clinical characteristics (n=99).

	n	Serum exo-eIF4E level		P-value
		Low (n=50)	High (n=49)
Age (years)				0.265
<65	53	24	29
≥65	46	26	20
Sex				0.461
Male	59	28	31
Female	40	22	18
Smoking status				0.774
Smoker	39	19	20
Nonsmoker	60	31	29
Size of tumor				0.056
<4 cm	50	30	20
≥4 cm	49	20	29
Histology				0.355
Adenocarcinoma	43	24	19
Squamous carcinoma	56	26	30
TNM stage				0.003*
I–II	39	27	12
III–IV	60	23	37
Lymph node metastasis				0.481
Negative	35	16	19
Positive	64	34	30
Distant metastasis				0.008*
Negative	67	40	27
Positive	32	10	22
CYFRA21-1 (ng/mL)				0.023*
<3.3	32	23	9
≥3.3	67	37	40
CEA (ug/mL)				0.776
<5	33	16	17
≥5	66	34	32

exo-eIF4E – exosomal eIF4E; CYFRA21-1 – cytokeratin fragment 19; CEA – carcinoembryonic antigen.