Table 3.

Relationship between TTF-1 expression and EGFR gene mutation status in tumors of different categories of patients

Category	Patient, n	TTF-1 expression	Status of TTF-1 expression and EGFR mutation
			EGFR(+)	EGFR(−)	Total	P-value
Overall status
	200	TTF-1(+)	83	80	163	0.000
		TTF-1(−)	6	31	37
		Total	89	111	200
Age
>61 years	94	TTF-1(+)	38	37	75	0.002
		TTF-1(−)	2	17	19
		Total	40	54	94
≤61 years	106	TTF-1(+)	45	43	88	0.025
		TTF-1(−)	4	14	18
		Total	49	57	106
Sex
Male	76	TTF-1(+)	19	35	54	0.080
		TTF-1(−)	4	18	22
		Total	23	53	76
Female	124	TTF-1(+)	64	45	109	0.001
		TTF-1(−)	2	13	15
		Total	66	58	124
Smoking
Ever	101	TTF-1(+)	29	45	74	0.021
		TTF-1(−)	4	23	27
		Total	33	68	101
Never	99	TTF-1(+)	54	35	89	0.034
		TTF-1(−)	2	8	10
		Total	56	43	99
Tumor location
Left	75	TTF-1(+)	32	31	63	0.001
		TTF-1(−)	0	12	12
		Total	32	43	75
Right	125	TTF-1(+)	51	49	100	0.015
		TTF-1(−)	6	19	25
		Total	57	68	125
Clinical stage
I–II	87	TTF-1(+)	34	35	69	0.003
		TTF-1(−)	2	16	18
		Total	36	51	87
III–IV	113	TTF-1(+)	49	45	94	0.013
		TTF-1(−)	4	15	19
		Total	53	60	113
Sex, smoking history
Female nonsmokers	87	TTF-1(+)	45	22	67	0.054
		TTF-1(−)	1	4	5
		Total	46	26	72
Others	113	TTF-1(+)	49	45	94	0.013
		TTF-1(−)	4	15	19
		Total	53	60	113

Abbreviations: EGFR, epidermal growth factor receptor; TTF-1, thyroid transcription factor-1.