Significance of HER2 protein expression and HER2 gene amplification in colorectal adenocarcinomas

Table 4 Association of human epidermal growth factor receptor 2 gene status with clinicopathological features n (%)

Clinicopathological features	HER2 status		P-value
	HER2 negative	HER2 positive
Gender			0.441
Male	616 (96.2)	24 (3.8)
Female	406 (97.1)	12 (2.9)
Age (yr)			0.272
≤ 60	501 (96.0)	21 (4.0)
> 60	521 (97.2)	15 (2.8)
Tumor grade			0.784
1	39 (97.5)	1 (2.5)
2	773 (96.7)	26 (3.3)
3	210 (95.9)	9 (4.1)
Histology			0.762
Tubular	937 (96.5)	34 (3.5)
Mucinous/other types	85 (97.7)	2 (2.3)
Tumor site			0.819
Colon	548 (96.5)	20 (3.5)
Rectal	474 (96.7)	16 (3.3)
Left-sided colon	203 (88.3)	27 (37.0)	0.514
Right-sided colon	292 (86.4)	46 (63.0)
Depth of invasion
T1	31 (100.0)	0 (0.0)	0.039
T2	165 (98.8)	2 (1.2)
T3	815 (96.3)	31 (3.7)
T4	11 (78.6)	3 (21.4)
T1-2	196 (99.0)	2 (1.0)	0.001
T3-4	826 (96.0)	34 (4.0)
Lymph node metastasis
N0	541 (96.3)	21 (3.7)	0.260
N1	261 (98.1)	5 (1.9)
N2	220 (95.7)	10 (4.3)
No	541 (96.3)	21 (3.7)	0.524
Yes	481 (97.0)	15 (3.0)
Distant metastasis			0.028
No	940 (96.9)	30 (3.1)
Yes	81 (92.0)	7 (8.0)
Tumor stage
(1)I-II	192 (98.5)	2 (1.0)	0.012
III	749 (96.5)	27 (3.5)
IV	81 (92.0)	7 (8.0)
(3)I-II	192 (99.0)	2 (1.0)	0.044
III-IV	830 (96.1)	34 (3.9)

HER2: Human epidermal growth factor receptor 2.