Alterations in the human epidermal growth factor receptor 2-phosphatidylinositol 3-kinase-v-Akt pathway in gastric cancer

Table 1 Clinicopathological characteristics of patients with gastric cancer

Variables (n = 231)		n (%)
Sex	Male	157 (68)
	Female	74 (32)
Age (yr)	Median (range)	71 (25-91)
Location	Cardias	82 (35)
	Body	62 (27)
	Antrum	83 (36)
	Unknown	4 (2)
Depth of invasion	T2	125 (54)
	T3	92 (40)
	T4	14 (6)
Lymph node metastasis	N0	65 (28)
	N+	158 (68)
	N1	73 (32)
	N2	56 (24)
	N3	29 (13)
	Unknown	8 (3)
Stage	IB	49 (21)
	II	45 (19)
	IIIA + IIIB	82 (35)
	IV	51 (22)
	Unknown	4 (2)
Lauren histotype	Intestinal	113 (49)
	Diffuse	112 (48)
	Others	6 (3)

Table 2 Clinicopathological characteristics of patients with gastric cancer based on human epidermal growth factor receptor 2 expression, phosphatidylinositol 3-kinase, catalytic, alpha polypeptide mutations and Epstein-Barr virus infection n (%)

		HER2			PIK3CA			EBV
		Positive(n = 20)	Negative(n = 211)	P value	Mutation(n = 20)	Wild type(n = 211)	P value	Positive(n = 18)	Negative(n = 204)	P value
Sex	Male	15 (75)	142 (67)	0.48	13 (65)	144 (68)	0.77	14 (78)	138 (68)	0.38
	Female	5 (25)	69 (33)		7 (35)	70 (32)		4 (22)	66 (32)
Age	Median	69 (50-84)	71 (25-91)	0.26	71 (25-85)	70 (38-91)	0.40	72 (48-90)	70 (38-91)	0.41
Location	Cardias	10 (50)	72 (34)	0.49	5 (25)	77 (36)	0.31	8 (44)	73 (36)	0.70
	Body	5 (25)	57 (27)		4 (20)	58 (27)		5 (28)	55 (27)
	Antrum	5 (25)	78 (37)		10 (50)	73 (35)		5 (28)	75 (37)
	Unknown	0	4 (2)		1 (5)	2 (1)		0	1 (0)
Depth	T2	12 (60)	113 (54)	0.48	8 (40)	117 (55)	0.15	12 (67)	106 (52)	0.35
	T3	8 (40)	84 (40)		9 (45)	83 (39)		6 (33)	85 (42)
	T4	0	14 (6)		3 (15)	11 (5)		0	13 (6)
L/N meta	N0	5 (25)	60 (28)	0.71	4 (20)	61 (29)	0.37	3 (17)	57 (28)	0.28
	N+	14 (70)	144 (68)		16 (80)	142 (67)		14 (77)	140 (69)
	N1	5 (25)	68 (32)		8 (40)	65 (31)		8 (44)	63 (31)
	N2	6 (30)	50 (24)		6 (30)	50 (24)		2 (11)	53 (26)
	N3	3 (15)	26 (12)		2 (10)	27 (13)		4 (22)	24 (12)
	Unknown	1 (5)	7 (3)		0	8 (4)		1 (6)	7 (3)
Stage	I	5 (25)	44 (21)	0.89	1 (5)	48 (23)	0.14	3 (17)	41 (20)	0.98
	II	3 (15)	42 (20)		7 (35)	38 (18)		4 (22)	39 (19)
	III	6 (30)	76 (36)		8 (40)	74 (35)		6 (33)	75 (37)
	IV	5 (25)	46 (22)		4 (20)	47 (22)		4 (22)	46 (23)
	Unknown	1 (5)	3 (1)		0	4 (2)		1 (6)	3 (1)
Lauren	Intestinal	15 (75)	98 (46)	0.05	14 (70)	99 (47)	0.13	5 (28)	105 (51)	0.04
histotype	Diffuse	5 (25)	107 (51)		6 (30)	106 (50)		13 (72)	93 (46)
	LELC	0	6 (3)		2 (10)	4 (2)		5 (28)	0
	Others	0	6 (3)		0	6 (3)		0	6 (3)
MSI		2 (10)	28 (13)	0.72	10 (50)	20 (9)	< 0.01	1 (6)	26 (13)	0.36
pAkt		16 (84)	103 (51)	< 0.01	12 (63)	107 (53)	0.37	8 (47)	103 (52)	0.69
3 yr OS (%)		29.4	59.2	0.24	57.3	56.8	0.59	57.4	57.3	0.98

MSI: Microsatellite instability; LELC: Lymphoepithelioma-like carcinoma; HER2: Human epidermal growth factor receptor 2; PIK3CA: Phosphatidylinositol 3-kinase, catalytic, alpha polypeptide mutations; EBV: Epstein-Barr virus; pAkt: Phospho Akt; OS: Overall survival.

Table 3 Frequencies of phosphatidylinositol 3-kinase, catalytic, alpha polypeptide mutations detected in gastric cancer tissues

	Mutation	Overall frequency	Percent/total cases	Percent/mutated cases	Microsatellite instability
Exon1	R88Q	1	0.4	5	1
	R108H	4	1.7	20	1
	Total	5	2.2		2
Exon9	E542K	5	2.2	25	1
	E545K	2	0.9	10	1
	E545G	2	0.9	10	1
	Total	9	4.0		3
Exon20	H1047Y	1	0.4	5	1
	H1047R	6	2.6	30	4
	Total	7	3.0		5