Table 3

K-ras mutation and p16 methylation in cholangiocarcinoma

Case	Stage	Grade	Codon	Mutation	Amino acid substitution	p21^rasIHC^3-a	p16 methylation^b	p16 IHC
Codon 12				GGT (wild type)	Glycine
1	II	1	12	GGT→AGT	Serine	++	++	—
2	IIIA	2	12	GGT→GAT	Aspartate	++	++	—
3	IIIA	2	12	GGT→GTT	Valine	++	++	—
4	IIIB	3	12	GGT→TGT	Cysteine	++	++	—
7	IIIA	2	12	GGT→GCT	Alanine	+	++	—
8	IVA	1	12	GGT→TGT	Cysteine	++	++	—
13	IIIA	1	12	GGT→TGT	Cysteine	++	++	—
14	IVA	3	12	GGT→GCT	Alanine	+	++	—
17	IIIA	2	12	GGT→GAT	Aspartate	++	++	—
25	IIIB	2	12	GGT→GCT	Alanine	+	++	—
28	IIIA	2	12	GGT→GTT	Valine	++	++	—
29	IVA	2	12	GGT→TGT	Cysteine	++	++	—
31	IIIA	2	12	GGT→TGT	Cysteine	++	++	—
33	IVA	2	12	GGT→GAT	Aspartate	++	++	—
35	IIIA	1	12	GGT→TGT	Cysteine	++	++	—
39	IIIA	2	12	GGT→AGT	Serine	+++	++	—
40	II	1	12	GGT→GTT	Valine	++	++	—
Codon 13				GGC (wild type)	Glycine
6	IIIA	1	13	GGC→GAC	Aspartate	+++	++	—
12	I	1	13	GGC→TGC	Cysteine	++	++	—
21	IVA	1	13	GGC→CAT	Aspartate	+	++	—
27	IVA	2	13	GGC→TGC	Cysteine	++	++	—
34	IIIA	1	13	GGC→GAC	Aspartate	+++	++	—
5 non-neoplastic tissue		12	GGT→GAT	Aspartate	+	—	++
11 non-neoplastic tissue		13	GGC→GAC	Aspartate	++	—	++

↵3-a IHC, defined by immunohistochemistry;
3-b methylation status defined by methylation specific polymerase chain reaction.