Analysis of clinical features, genomic landscapes and survival outcomes in HER2-low breast cancer

Table 2 Metastatic Sites Stratified by HER2 Status

	HER2-zero N = 220		HER2-low N = 194		HER2+ N = 165		P value
Initial metastatic sites
Lung	87	39.6%	79	40.7%	78	47.3%	P vs L: 0.22 Z vs L: 0.81
Liver	49	22.3%	52	26.8%	42	25.5%	P vs L: 0.77 Z vs L: 0.28
Bone	65	29.6%	81	41.8%	45	27.3%	P vs L: 0.004 Z vs L: 0.01
Metastatic sites
Brain	23	10.5%	29	15.0%	33	20.0%	P vs L: 0.21 Z vs L: 0.17
Lung	117	53.2%	98	50.6%	95	57.6%	P vs L: 0.18 Z vs L: 0.59
Liver	94	42.7%	105	54.1%	69	41.8%	P vs L: 0.02 Z vs L: 0.02
Bone	113	51.4%	128	66.0%	66	40.0%	P vs L: < 0.0001 Z vs L:0.003

	HR+HER2-zero N = 66		HR+HER2-low N = 116		HR+HER2+ N = 42		P value
Initial metastatic sites
Lung	17	25.8%	49	42.2%	20	47.6%	P vs L: 0.547 Z vs L:0.026
Liver	15	22.7%	30	25.9%	13	31.0%	P vs L: 0.525 Z vs L:0.637
Bone	32	48.5%	58	50.0%	20	47.6%	P vs L: 0.791 Z vs L: 0.844
Metastatic sites
Brain	3	4.6%	17	14.7%	7	16.7%	P vs L: 0.756 Z vs L: 0.036
Lung	31	47.0%	63	54.3%	24	57.2%	P vs L: 0.75 Z vs L: 0.341
Liver	41	62.1%	70	60.3%	23	54.8%	P vs L: 0.529 Z vs L: 0.813
Bone	51	77.3%	90	77.6%	25	59.5%	P vs L: 0.024 Z vs L: 0.961

	HR–HER2-zero N = 154		HR–HER2-low N = 78		HR–HER2+ N = 123		P value
Initial metastatic sites
Lung	70	45.45%	30	38.46%	58	47.15%	P vs L: 0.226 Z vs L: 0.31
Liver	34	22.08%	22	28.21%	29	23.58%	P vs L: 0.463 Z vs L: 0.303
Bone	33	21.43%	23	29.49%	25	20.33%	P vs L: 0.138 Z vs L: 0.175
Metastatic sites
Brain	20	12.98%	12	15.38%	26	21.14%	P vs L: 0.31 Z vs L: 0.617
Lung	86	55.84%	35	44.87%	71	57.77%	P vs L: 0.075 Z vs L: 0.114
Liver	53	34.42%	35	44.87%	46	37.40%	P vs L: 0.292 Z vs L:0.121
Bone	62	40.26%	38	48.72%	41	33.33%	P vs L: 0.03 Z vs L:0.219

Bold value indicates the siginificant P values
HER2+: HER2-positive; HR−: HR-negative; HR+: HR-positive; P: HER2-positive; L: HER2-low; Z: HER2-zero;
HER2 Status was defined by the most recent pathological result
The P value was calculated by Chi-square test

ISSN: 1479-5876