Survival analysis based on human epidermal growth factor 2 status in stage II-III gastric cancer

Table 1 Demographics and baseline characteristics n (%)

Characteristic	Stage II (n = 193, II A: 97, II B: 96)	Stage III (n = 191, III A: 55, III B: 63, III C: 73)
Median age (range, yr)	61.27 ± 12.75 (28-90)	62.21 ± 13.20 (33-86)
Gender
Male	124 (64.2)	114 (59.7)
Female	69 (35.8)	77 (40.3)
ECOG PS
0	119 (61.7)	76 (39.8)
1	74 (38.3)	114 (59.7)
2	0	1 (0.5)
HER2 status
HER2 positive
IHC 3 (+)	15 (7.8)	13 (6.8)
IHC 2 (+)/FISH (+)	2 (1.0)	2 (1.0)
HER2 negative
IHC 2 (+)/FISH (-)	6 (3.1)	4 (2.1)
IHC 1 (+) or 0	168 (87.1)	169 (88.5)
IHC not done/FISH (-)	2 (1.0)	3 (1.6)
Pathologic differentiation
WD TA	7 (3.6)	3 (1.6)
MD TA	54 (28.0)	44 (23.0)
PD TA	96 (49.7)	111 (58.1)
Signet ring cell carcinoma	33 (17.1)	27 (14.1)
Others	3 (1.6)	6 (3.2)
T stage
T1	17 (88.1)	0
T2	48 (24.9)	4 (2.1)
T3	90 (46.6)	51 (26.7)
T4	38 (19.7)	136 (71.2)
N stage
N0	97 (50.3)	1 (0.5)
N1	60 (31.0)	30 (15.7)
N2	33 (17.1)	52 (27.3)
N3	3 (1.6)	108 (56.5)
Received adjuvant chemotherapy
Yes	141 (73.1)	161 (84.3)
No	52 (26.9)	30 (15.7)

ECOG PS: Eastern Cooperative Oncology Group Performance Status; HER2: Human epidermal growth factor receptor 2; GEJ: Gastroesophageal junction; IHC: Immunohistochemistry; FISH: Fluorescence in situ hybridization; WD: Well differentiated; MD: Moderately differentiated; PD: Poorly differentiated; TA: Tubular adenocarinoma.

Table 2 Human epidermal growth factor receptor 2 expression and clinicohistologic characteristics

Author	n	Histologic type				Localization			Method
		Intestinal (%)	Diffuse (%)	Mixed / unknown (%)	P	GEJ (%)	Gastric (%)	P value
Tanner et al[6]	231	21.5	2	5	0.005	24	12	-	CISH
Gravalos et al[23]	166	16	7	14	0.27	25	9.5	0.01	IHC, FISH
Lordick et al[24]	1527	34	6	20	-	32	18	-	IHC, FISH
Present study	384	17	2.5	18	< 0.01	20	9.5	0.008	IHC, FISH

GEJ: Gastro-esophageal junction; CISH: Chromogenic in situ hybridization; FISH: Fluorescence in situ hybridization; IHC: Immunochistochemistry.

Table 3 Univariate and multivariate analysis showing factors associated with overall survival

Variable	Univariate		Multivariate
	HR (95%CI)	P value	HR (95%CI)	P value
HER2 status	0.424 (0.208-0.865)	0.018	0.421 (0.206-0.861)	0.018
WD-MD vs PD-SRC	0.694 (0.374-1.290)	0.248
Sex	1.376 (0.821-2.307)	0.226
ECOG PS	2.149 (1.648-2.803)	< 0.001	2.002 (1.530-2.618)	< 0.001
Age (< 65)	1.408 (0.837-2.369)	0.197
Adjuvant chemotherapy	1.750 (0.978-3.128)	0.059

HR: Hazard ratio; CI: Confidence interval; HER2: Human epidermal growth factor receptor 2; WD: Well differentiated; MD: Moderately differentiated; PD: Poorly differentiated; SRC: Signet ring cell carcinoma; ECOG PS: Eastern Cooperative Oncology Group Performance Status.