Table 5.

Postoperative survival and TTF-1 expression and EGFR gene mutation status in different categories of patients

Category	TTF-1		EGFR
	χ2	P-value	χ2	P-value
Age
>61 years	0.096	0.757	2.330	0.127
≤61 years	3.729	0.053	0.763	0.382
Sex
Male	0.381	0.537	1.062	0.303
Female	0.281	0.596	2.134	0.144
Smoking
Ever	0.068	0.795	2.011	0.156
Never	1.224	0.269	0.427	0.514
Tumor location
Left	0.000	0.999	2.889	0.089
Right	1.562	0.211	0.487	0.485
Pathological stage
I–II	0.889	0.346	1.638	0.201
III–IV	4.578	0.032	2.075	0.150

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