Detection of EpCAM positive and negative circulating tumor cells in metastatic breast cancer patients

Figures & data

Figure 1. EpCAM expression of two luminal cell lines (A) MCF-7, (B) ZR-75-1 and one basal like (C) Hs578T cell line. MCF-7 and ZR-75-1 cells have a significantly higher EpCAM expression than Hs 578T cells (p < 0.001).

Table I. Recovery rates of spiking experiments of the EpCAM (+) cell lines, MCF-7 and ZR-75-1, and the EpCAM (−) cell line, Hs 578T. To enrich tumor cells one EpCAM dependent assay, MACS HEA MicroBeads^®, and one EpCAM independent assay, OncoQuick^® plus, were used.

	MACS HEA MicroBeads^®
Cell line	Mean number of spiked cells (range)	Median (%) of spiked cells recovered (CI)^1
MCF-7	108.00 (6–410)	76.35 (72.62–80.08)
ZR-75-1	34.90 (5–106)	75.00 (71.45–78.55)
Hs 578T	48.10 (2–98)	3.92 (0.00–7.14)
	OncoQuick^® plus
	Mean number of spiked cells (range)	Median (%) of spiked cells recovered (CI)^1
MCF-7	89.85 (11–390)	57.89 (50.83–64.95)
ZR-75-1	40.10 (5–101)	59.80 (51.87–67.73)
Hs 578T	47.75 (3–105)	57.14 (40.00–75.24)

¹CI, 95% Confidence Interval.

Figure 2. Box plots demonstrating that basal like Hs 578T EpCAM (−) tumor cells are enriched to a significant lesser extent with the EpCAM dependent enrichment method, MACS HEA MicroBeads^®, compared to luminal EpCAM (+) cell lines, MCF-7 and ZR-75-1. Vice versa, an EpCAM independent enrichment method, OncoQuick^® plus, enriches EpCAM (−) and EpCAM (+) tumor cells without significant difference. MACS HEA MicroBeads^® recovered significantly more EpCAM (+) cells compared to OncoQuick^® plus. Vice versa, OncoQuick^® plus recovered significantly more of EpCAM (−) Hs 578T tumor cells.

Table II. Detection rates of circulating tumor cells (CTCs) by two enrichment technologies according to the clinical pathological patient variables at the time of their diagnosis.

			Enrichment technology used for CTC enumeration
			MACS HEA MicroBeads^®			OncoQuick^® plus
Variable	Cases (n = 26)	%	Number of patients with CTCs	%	p-value	Number of patients with CTCs	%	p-value
Menopausal status
Premenopausal	9	34.6	4	44.4	0.873	7	77.8	0.492
Postmenopausal	17	65.4	7	41.2		11	64.7
Receptor status
ER positive	21	81.5	12	56.3	0.129	13	62.5	0.636
ER negative	5	18.5	1	20.0		4	80.0
PR positive	11	42.3	6	54.5	0.393	7	63.6	0.680
PR negative	15	57.7	5	33.3		11	73.3
Her/2neu status
Her/2 neu positive	7	26.9	4	57.1	0.353	6	85.7	0.269
Her/2 neu negative	19	73.1	7	36.8		12	63.2
Ki-67 status
Ki-67 ≥ 14%	17	65.4	8	47.1	0.402	12	70.6	0.837
Ki-67 < 14%	9	34.6	3	33.3		6	66.7
Breast cancer subgroups
Luminal B^1	11	42.3	6	54.5	0.121	6	54.5	0.344
Her/2 neu positive^2	7	26.9	4	57.1		6	85.7
Basal like^3	8	30.8	1	12.5		6	75.0
Histology
Ductal	19	73.1	9	47.4	0.390	13	68.4	0.883
other	7	26.9	4	52.6		2	31.6
Pathologic tumor size
pT1	11	42.3	7	63.6	0.548	9	81.8	0.254
pT2	9	34.6	3	33.3		6	66.7
pT3	1	3.8	1	100.0		1	100.0
pT4	5	19.2	2	40.0		4	80.0
Lymph node status
Negative	8	30.8	4	50.0	0.813	5	66.7	0.583
Positive	18	69.2	9	50.0		6	33.3
Tumor Grade
G1	0	0.0	0	0.0	0.390	0	0.0	0.077
G2	7	26.9	2	28.6		3	42.9
G3	19	73.1	9	47.4		15	78.9

¹ER (+) and/ or PR (+) and Her/2neu negative and/ or Ki-67 high.

²ER (+/−) PR (+/−), Her/2neu positive.

³ER (−), PR (−), Her/2neu (−), EGFR (+) and/ or CK 5/6 (+).

Table III. CTC detection rates according to the two CTC enrichment methods, MACS HEA MicroBeads^® and OncoQuick^® plus, of diverse breast cancer subtypes in 26 breast cancer patients.

	MACS HEA MicroBeads^®		OncoQuick^® plus
Breast cancer subtypes	Median of CTCs detected (range)	p-value	Median of CTCs detected (range)	p-value
Luminal B^1	1.00 (0–30)	0.197	6.00 (0–21)	0.326
Her/2neu^2	1.00 (0–61)		10.00 (0–339)
Basal like^3	0.00 (0–3459)		13.50 (0–2895)

¹ER (+) and/ or PR (+) and Her/2neu negative and/ or Ki-67 high.

²ER (+/−) PR (+/−), Her/2neu positive.

³ER (−), PR (−), Her/2neu (−), EGFR (+) and/ or CK 5/6 (+).

Figure 3. Box plots showing the detection rate of EpCAM (−) and EpCAM (+) CTCs enriched with MACS HEA Micro Beads^® and OncoQuick^® plus, respectively.

Figure 4. No, low level and high level EpCAM expressions, respectively, according to primary breast cancer subtypes of 22 breast cancer patients.