Relationships among KRAS mutation status, expression of RAS pathway signaling molecules, and clinicopathological features and prognosis of patients with colorectal cancer

Table 4 Relationship between MEK and ERK protein expression and clinicopathological features of colorectal cancer patients

General data		MEK protein			ERK protein
		Positive rate (%)	P-value	χ²	Positive rate (%)	P-value	χ²
Median age (yr)	< 56	62.9 (44/70)	0.097	0.756	46.5 (33/71)	0.822	0.365
	≥ 56	65.1 (82/126)			53.2 (66/124)
Gender	Male	68.1 (77/113)	1.728	0.189	51.3 (58/113)	0.034	0.855
	Female	59.0 (49/83)			50 (41/82)
Differentiation	Medium-low	64.5(100/155)	0.017	0.896	46 (69/150)	6.012	0.015
	Well	63.4 (26/41)			66.7 (30/45)
Infiltration depth	T1 + T2	68.4 (26/38)	0.356	0.553	51.4 (19/37)	0.006	0.937
	T3 + T4	63.3 (100/158)			48.2 (80/166)
Lymph node metastasis	N0	63.0 (58/92)	0.117	0.733	47.8 (44/92)	0.604	0.437
	N1-N3	65.4 (68/104)			53.4 (55/103)
Distant metastasis	M0	60.3 (91/151)	4.631	0.031	49 (74/151)	0.832	0.362
	M1	77.8 (35/45)			56.8 (25/44)
TNM stage	I	72 (18/25)	5.89	0.117	52.0 (13/25)	2.435	0.487
	II	57.9 (33/57)			43.63 (25/57)
	III	58.6 (41/70)			50 (35/70)
	IV	77.3 (34/44)			59.1 (26/44)