Table 1. Demographics and clinical characteristics of patients with lung cancer, as well as the association with the expression of CK20 and CK7.

Variables	Expression of CK20 (n=258)			Expression of CK7 (n=258)
	Negative expression (n=61)	Positive expression (n=197)	P	Negative expression (n=54)	Positive expression (n=204)	P
Sex
Male	34	121	0.428	22	133	0.001
Female	27	76		32	71
Age (years)
<60	25	71	0.485	30	66	0.002
≥60	36	126		24	138
Smoking
No	18	73	0.281	17	74	0.512
Yes	43	124		37	130
T stage
T1–2	38	79	0.002	26	71	0.072
T3–4	23	118		28	133
Lymph node metastasis
No	36	74	0.003	29	73	0.017
Yes	25	123		25	131
Invasion
No	21	113	0.002	28	74	0.037
Yes	40	84		26	130
Size (cm)
<3	43	109	0.035	34	118	0.497
≥3	18	88		20	86
Differentiation
Well	21	91	0.106	16	96	0.022
Poor	40	106		38	108
Clinical stage
Stage I	23	120	0.006	29	114	0.732
Stage II	25	51		15	61
Stage III	13	26		10	29