HER2 heterogeneity is a poor prognosticator for HER2-positive gastric cancer

Table 1 Patients’ demographic information

	Homo, n = 65	Hetero, n = 23	P-value
Age in yr	69 (42-81)	67.0 (45-82)
< 70	34 (52%)	15 (65%)	0.284
≥ 70	31 (48%)	8 (35%)
Sex
Male	43 (66%)	18 (78%)	0.279
Female	22 (34%)	5 (22%)
ECOG performance status
0	61 (94%)	20 (87%)	0.152
1	2 (3%)	3 (13%)	(0 vs ≥ 1)
2	2 (3%)	0
Macroscopic type
1	7 (11%)	1 (5%)	0.008
2	28 (43%)	4 (17%)	(type 1/2 vs 3/4)
3	23 (35%)	16 (69%)
4	7 (11%)	2 (9%)
Tumor location
Upper	27 (42%)	11 (48%)	0.601
Middle / lower	38 (58%)	12 (52%)
Histology
Well differentiated	48 (74%)	14 (61%)	0.31
Poorly differentiated	15 (23%)	9 (39%)
Other/unknown	2 (3%)	0
T status
cT2	2 (3%)	0	0.267
cT3	17 (26%)	4 (17%)	(cT2/3 vs cT4)
cT4	46 (71%)	19 (83%)
N status
cN0	5 (8%)	2 (9%)	0.748
cN1	5 (8%)	1 (4%)	(≤cN2 vs cN3)
cN2	32 (49%)	11 (48%)
cN3	23 (35%)	9 (39%)
Number of non-curative factor
0	1 (1%)	1 (4%)	0.404
1	32 (49%)	13 (57%)	(≤1 vs >1)
2	29 (45%)	9 (39%)
>2	3 (5%)	0
Non-curative factor
Lymph node	34 (52%)	10 (43%)
Peritoneal	22 (34%)	6 (26%)
Hepatic	27 (42%)	12 (52%)
Other	9 (14%)	1 (5%)
Number of HER2 assessment
2	35 (54%)	10 (43%)	0.393
3	27 (42%)	13 (57%)
>3	3 (4%)	0
HER2 score
3+	53 (82%)	10 (43%)	0.001
2+	12 (18%)	13 (57%)
Upfront chemotherapy
SOXT	33 (50%)	12 (52%)
XPT	25 (37%)	7 (30%)
SPT	3 (5%)	2 (9%)
FPT	1 (2%)	2 (9%)
FLT	1 (2%)
PTXT	1 (2%)
DCST	1 (2%)

ECOG: Eastern Cooperative Oncology Group; SOXT: S-1 oxaliplatin capecitabine trastuzumab; XPT: capecitabine cisplatin trastuzumab; SPT: S-1 cisplatin trastuzumab; FPT: 5-Fluorouracil cisplatin trastuzumab; FLT: 5-Fluorouracil leucovorin trastuzumab; PTXT: Paclitaxel trastuzumab; DCST: Docetaxel cisplatin S-1 trastuzumab.