Table 4.

Changes in circulating tumor cell (CTC) count and in human epidermal growth factor receptor 2 (HER2) status in CTCs from baseline to first follow-up

Baseline						First follow-up
HER2 status in CTCs	No. of patients (%)	No. of CTCs				HER2 status in CTCs	No. of patients (%)	No. of CTCs
		Total	HER2 overexpressed by ICC	Examined by FISH	HER2 amplified by FISH			Total	HER2 overexpressed by ICC	Examined by FISH	HER2 amplified by FISH
Positive	8 (15.4)	6,067	0	50	6	Positive	3 (5.8)	1,938	0	50	6
		1,128	0	50	2			1,100	0	50	3
		220	118	50	50			10	3	7	3
		56	0	40	3	Negative	2 (3.8)	4	0	2	0
		3	1	1	1			2	0	0	0
		1,577	1119	50	50	No CTCs	2 (3.8)	0	0	0	0
		7	2	5	1			0	0	0	0
		15	3	10	1	NA	1 (1.9)	NA	NA	NA	NA
Negative	23 (44.2)	13	0	9	0	Positive	3 (5.8)	39	0	27	1
		12	0	14	0			12	1	7	0
		2	0	1	0			4	1	3	1
		97	0	50	0	Negative	12 (23.1)	1	0	0	0
		76	0	50	0			26	0	18	0
		50	0	35	0			3	0	1	0
		43	0	30	0			44	0	30	0
		12	0	10	0			3	0	1	0
		11	0	7	0			2	0	0	0
		10	0	8	0			5	0	3	0
		3	0	2	0			2	0	2	0
		2	0	2	0			4	0	3	0
		2	0	1	0			1	0	0	0
		2	0	0	0			19	0	13	0
		1	0	1	0			1	0	0	0
		6	0	4	0	No CTCs	8 (15.4)	0	0	0	0
		4	0	2	0			0	0	0	0
		3	0	2	0			0	0	0	0
		2	0	0	0			0	0	0	0
		2	0	2	0			0	0	0	0
		1	0	0	0			0	0	0	0
		1	0	0	0			0	0	0	0
		1	0	0	0			0	0	0	0
No CTCs	21 (40.4)					Negative	1 (1.9)	4	0	2	0
		0	0	0	0	No CTCs	18 (34.7)	0	0	0	0
						NA	2 (3.8)	NA	NA	NA	NA

HER2 human epidermal growth factor receptor 2, CTCs circulating tumor cells, FISH fluorescence in situ hybridization, ICC immunocytochemistry, NA not assessed