Table 1.

Correlation between clinicopathological features and K-RAS mutation of codon 12 1^st base and codon 13 2^nd base

		mutation of codon 12 1st base				mutation of codon 13 2nd base
		no	yes	total	p-value	no	yes	total	p-value
Tumor size	<= 3 cm	55	5	57	1	56	1	57	0.03
	>3 cm	160	8	168		149	19	168
Grade	Well	4	0	4	0.749	4	0	4	0.416
	Moderate	171	9	180		161	19	180
	Poor	10	1	11		11	0	11
Lymph node metastasis	-	107	2	109	0.048	101	8	109	0.621
	+	88	8	96		87	9	96
Stage	I, II	76	0	76	0.121	70	6	76	0.782
	III, IV	76	4	80		72	8	80
Survival	<= 5 years	114	9	123	0.023	109	14	123	0.162
	>5 years	104	1	105		99	6	105

p-value by Chi-square Test or Fisher's Exact Test when appropriated